Felicity Thomas is the former Associate Editorial Director of Pharmaceutical Technology, Pharmaceutical Technology Europe, BioPharm International.

Felicity Thomas

	A vast global study on the public’s attitude towards science, scientists, and health recently been published by Wellcome (1) has demonstrated an overall positive trust in science. However, the results are perhaps tinged with some concern, particularly in terms of certain attitudes towards vaccines.

	The Wellcome Global Monitor comprises the responses of more than 140,000 people located in over 140 countries, making it the largest study of its kind to date (1). Although the questions were aimed at assessing global attitudes towards science in general, there was also a series of questions devoted to vaccines.

	Overall, the key findings of the report have demonstrated that the majority of people (72% of respondents) trust scientists. However, more than half of the respondents believe that they do not know very much about science; a gender gap, in terms of knowledge, was apparent from the results, with men more likely to claim they have a greater knowledge of science than women.

	These results are probably in tune with smaller studies that have been performed, commonly with a bias towards the United States and Europe. Additionally, other regional studies have confirmed the gender disparity found in those studying science subjects at various levels and of those in the science, technology, engineering, and mathematics (STEM) workforce. Although, according to annual statistics, released by Women into Science and Engineering campaign in the United Kingdom, there has been a steady increase in the number of women taking up a STEM career path in recent years (2). 

	Vaccines were specifically targeted in the Wellcome Global Monitor due to the impact they have on global health. The World Health Organization has specified that delay of acceptance or a rejection of vaccines represents one of the top 10 threats to global health in 2019 (3).

	Despite nearly 80% of respondents ‘somewhat’ or ‘strongly’ agreeing that vaccines are safe, the report also demonstrated that there was less certainty on safety in high-income regions. Respondents from France had the least belief in vaccine safety, with one in three people disagreeing that they are safe. The regions with the highest belief in vaccine safety were South Asia (95%) and Eastern Africa (92%).

	These results are perhaps a little discerning, particularly given the fact that there was a spike in measles cases witnessed globally, with the greatest upsurge seen in the Americas, the Eastern Mediterranean region, and Europe in 2017, as reported by WHO (4).

	“The increase in measles cases is deeply concerning, but not surprising,” said Seth Berkley, CEO of Gavi, the Vaccine Alliance in the news release (4). “Complacency about the disease and the spread of falsehoods about the vaccine in Europe, a collapsing health system in Venezuela, and pockets of fragility and low immunization coverage in Africa are combining to bring about a global resurgence of measles after years of progress.”

	In 2018, the European Commission published a preliminary report from an expert panel on vaccinations and health systems in Europe, which highlighted the main factors influencing vaccine uptake and measures that could help improve vaccination coverage (5). As some of the obstacles to vaccine uptake were identified as anxieties over safety and side effects, as well as a lack of trust, measures to help overcome these and improve uptake included reliable information, positive media messages, and building trust in institutions and providers.

	The pharma industry certainly can help the public overcome anxieties of safety and side. The Association of the British Pharmaceutical Industry, for example, has already published a series of infographics on the benefits of vaccines for public health, the socio-economic impact of vaccines, and the future of vaccines to help provide information on the value of these life-saving products (6). 

	Furthermore, vaccinations can help combat the antimicrobial resistance crisis, which is increasing globally year-on-year. Pfizer has recently urged the European Commission to put forward a legislative proposal on against antimicrobial resistance, which includes ‘pull’ mechanisms at the European Union level, to incentivise research into new vaccines and treatments (7). 

	It will be interesting to see how the global monitor results are applied throughout science and within pharma over the coming months and whether positive influence will garner greater trust in science in the future.

	1. Wellcome, “Wellcome Global Monitor,” Report, 19 June 2019.
	2. WISE, “Annual Report-April 2017–March 2018,” Report, July 2018.
	3. WHO, “Ten Threats to Global Health in 2019,” Emergency Notice [accessed 19 June 2019].
	4. WHO, “Measle Cases Spike Globally Due to Gaps in Vaccination Coverage,” News Release, 29 Nov. 2018.
	5. EC, “Expert Panel on Effective Ways of Investing in Health: Vaccination Programmes and Health Systems in the European Union,” Report, 26 Sept. 2018.
	6. ABPI, “Vaccines,” Infographics [accessed 19 June 2019].
	7. Pfizer, “Committed to the Fight Against Antimicrobial Resistance (AMR),” Article, 

	When referring to this article, please cite it as F. Thomas, “A Wellcome Result for Science,” 

Articles

The Wellcome Global Monitor has demonstrated an overall positive trust in science but some concerns still remain on attitudes on vaccines.


A Wellcome Result for Science

According to market forecasts, the global oral solidâdosage (OSD) pharmaceutical formulation market is anticipated to grow by a compound annual rate of 6.5%, reaching a little less than US$930 billion by the end of 2027 (1). This growth rate stands to reason, as solid dosage forms remain the most popular and commonly used drug form within the industry.

	“OSD forms, such as tablets and powder-filled capsules, are the most popular in the industry,” says Ronak Savla, global scientific affairs manager at Catalent. “These drug forms are cost-effective, scalable, and acceptable to patients. However, the manufacture of OSD forms is becoming less straightforward than API-excipient blends compressed into tablets or filled in capsules.”

	Over the past decade, Savla notes that there has been a steady increase in the number of drugs formulated as solid dispersions, driven by technology advances and the increasing number of poorly soluble drug candidates. 

	Concurring with Savla, Krizia Karry, global technical marketing manager at BASF Pharma Solutions, specifies that technological advances enabling the ability to manufacture OSD forms of poorly water-soluble drugs is one of three major trends impacting the industry. “Technologies such as hot-melt extrusion and spray drying, which allow for the drug to be solubilized in a polymeric carrier and subsequently formulated into a tablet, have seen growth,” she says.

	In Karry’s opinion, approaches to improve patient compliance and continuous manufacturing have been two further trends in the field of OSD formulation. “It is no secret that a large percent of the population has difficulty swallowing tablets and capsules. As a consequence, formulations such as oral dispersible tablets and mini-tablets have expanded the ability of patients to take lifesaving medications,” she notes.

	“Finally, the adoption of continuous manufacturing platforms for solid oral dosage forms offers a cost-competitive advantage by reducing overall manufacturing footprint, accelerating drug product development, allowing for flexible batch sizes, being amenable for real-time release testing, and by enabling higher assurance of product quality through automated control strategies that react to process disturbances,” Karry continues. 

	Harald Stahl, head of application development at GEA, raises the point that the industry is moving away from the blockbuster and toward the development of specialized drugs that target rare and orphan diseases. “Consequentially, batch sizes decrease while at the same time prices per dose go up,” he adds. “As a result, companies are looking into technologies that allow for the necessary development and scale-up activities while using minimal amounts of API-one of the main drivers into continuous processing.”

	“More than ever before, pharmaceutical companies are taking a holistic approach when formulating new drug products so that patients are at the center of everything they do,” says Jessica Mueller-Albers, strategic marketing director for oral drug delivery solutions at Evonik. “This has strengthened demand for solutions that can improve rates of patient compliance and brand preference, such as the development of pediatric or geriatric dosage forms, as well as coatings that enhance swallowability.”

	Furthermore, Bruhalkumar Shah, senior formulation scientist at Cambrex highlights that outsourcing of pharmaceutical development and/or manufacturing to various contract organizations has also been rising. This is a result of an increase in merger and acquisition activity, pharmaceutical company downsizing, and the emergence of virtual companies, he explains.

	“Each of the sector trends, however, require excipients that are ‘fit-for-purpose’ to overcome the various challenging tasks that face formulators of OSD drugs,” stresses Karry. 

Key considerations for excipient selection

	“Careful consideration must be taken in the selection of any functional or non-functional excipient as it greatly impacts the quality and efficacy of the finished product,” says Shah. “Special attention should be given to functional excipients, which can directly impact the stability of the product or can change pharmacokinetic performance, such as with controlled or modifiedârelease products.” 

	Excipients are rarely now just bulking agents, asserts Savla. “Rather, such agents are increasingly used to serve an additional function, such as improving solubility. It is highly likely that multiple excipients, each serving a different function, are required,” he notes. “Polymers used in amorphous solid dispersions retard recrystallization of amorphous drug molecules. Understanding the functionality, stability, and API interactions of the excipients is paramount.” 

	Karry adds that of primary importance is an understanding of API properties and solubility in common solvents. “From there, formulation screening methods vary depending on whether the excipient helps solubilize the drug (e.g., by complexation or solid solution systems where the API is solubilized in a polymeric carrier) and pharmacokinetic considerations such as the rate of administration (instant or modified release), and preferred site of drug absorption (pH dependent solubility),” she says. Further considerations are then made on a case-by-case basis but may include processing aids (glidants and lubricants), drug abuse deterrents, taste-masking or moisture protection coatings, and antioxidants to protect the API from oxidation reactions, among others, Karry states.

	The first step is certainly screening of API compatibility, specifically, chemical and physical stability in a panel of common excipients used in regulatory-approved products, agrees Savla. “The goal of compatibility screening is to minimize risks, costs, and formulation development time,” he explains. “Some key areas of focus are keeping the drug in an amorphous state (for amorphous solid dispersions), change in polymorphism, and chemical degradation. Based on these results, formulation prototype development with other ingredients (binders, fillers, disintegrants etc.) is undertaken. For hot-melt extrusion, the miscibility of API and polymer is important, as is the melting temperature of the polymer.”

	Then, it is vital to consider the amount of excipient in the formulation, as this should be kept under the maximum allowable potency per dose. “For pediatric patients, the number of allowable excipients is rather limited,” Savla continues. “An adult formulation may not be acceptable for pediatric use by regulatory authorities based on the components. Therefore, the formulator is challenged with designing a different formulation while maintaining safety and efficacy.”

	If using large amounts of excipients in a dosage form, there may be a requirement to have a larger dosage unit or for the patient to take multiple doses to achieve the correct dosage of API, which can lead to swallowability and adherence issues. “The formulator must study the drug loading when choosing polymers for amorphous dispersions. Simply choosing the formulation with the highest drug load is not recommended, as high drug loading may lead to a higher propensity for recrystallization in an amorphous solid dispersion,” Savla stresses.

	“The growing complexity of drug products has increased demand for specialized excipients and other delivery technologies that can facilitate the targeted release of the API at the right place over the right duration,” emphasizes Mueller-Albers. The crucial role these agents play in the properties and performance of the final drug product has meant that regulatory authorities have scrutinized the functionality and quality of excipients closely over the past decade.

	“As a result of this scrutiny, pharmaceutical companies have been prompted to take a science- and risk-based approach towards the selection of excipients that are widely accepted across all key worldwide markets,” Mueller-Albers adds. Without the appropriate attention to excipient quality, companies may be taking significant risks to drug development and could end up with production downtime and supply shortages, she warns.

	“As mentioned earlier, industry has been witnessing a shift away from the blockbuster style drug product and, as such, is seeing volumes of manufacturing decrease,” says Stahl. “Therefore, several companies have been focusing on a direct compression method, which negates the need for the wet granulation step, while also increasing the requirements on the physical characteristics of APIs as well as the excipients.”

	Successful application of the direct compression method requires a critical selection of excipients, to ensure good flowability and compressibility. “Powder flow is an extremely important property for processes such as tableting and capsule filling, and therefore, excipients that can improve powder flow for ‘difficult’ powder blends are of interest to formulators,” emphasizes Savla. “These can be excipient grades with a particular particle-size and shape to provide good flow properties, or co-processed materials (e.g., silicified microcrystalline cellulose), which offer similar advantages.”

	Co-processed materials are now more widely available and offer formulators a single, multi-functional excipient option, which helps to reduce development time and cost, particularly in early development phases, Savla explains. “Further, easy-to-prepare products, such as preformulated coating preparations for tablets are now freely available and can also cut down on processing time.”

	As the drug development process itself becomes more complex, excipient suppliers are required to follow the various industry trends and innovate, confirms Shah. “Important advances have been seen specifically when developing novel drug delivery systems,” he says. 

	Giving some examples, Shah highlights that excipient advances have been seen as a result of industry trends towards immediate and controlled dosage forms, specialized delivery systems for poorly soluble molecules, and nanotechnology. “So, co-processed excipients and the development of new grades of existing excipients have helped with immediate and controlledârelease dosage forms,” he adds. “Then for specialized delivery systems, cyclodextrins, mesoporous silica, new polymers to inhibit crystallization, and copolymer dispersions for taste-masking have been introduced. In terms of nanotechnology, the sector has seen the use of PEGylated derivatives and drug targeting moieties for stabilization and specificity, respectively.” 

	However, Karry states that innovation has remained relatively slow. “Naturally, it is a significant gamble for pharmaceutical companies to utilize novel or innovative excipients in formulations, largely due to the increased risk on the drug filing,” she says. “Nevertheless, innovation for excipients continues.”

	“Even though there are a number of excipient options available today with a strong history of safety and performance, there are still unmet market needs when it comes to functionality,” notes Mueller-Albers. “As one example, despite several companies seeking to develop new permeation-enhancing solutions, there is still a clear need for additional excipient offerings or drug delivery technologies that can better address poor permeability. Likewise, despite the use of solid dispersions to help address poor solubility, we are still seeking specialized solutions that can tackle the bioavailability constraints of certain new drug entities.”

	In Savla’s opinion, despite growth in the number of acceptable excipients available to help with solubility enhancement, it remains one of the main issues for formulators. “There continues to be a need for new excipients that can help overcome the challenges offered by chemically diverse compounds,” he explains. “The limited number of polymers used in amorphous solid dispersions is not adequate to cover the wide chemical diversity of drug molecules.”

	Additionally, Savla believes that there is a great unmet need in the number of pediatric-appropriate excipients that are considered to be acceptable by regulatory authorities. “The development of pediatric medicines has become of key importance within the pharmaceutical industry as developers are increasingly required to conduct clinical studies in pediatric populations with appropriate formulations first, before going on to get regulatory approval for adult formulations,” he states.

Slow progress in oral delivery of biologics

	It is generally known that oral administration of biopharmaceutical products has been limited and progress within the field slow. “Most macromolecules are still formulated into parenterals and applied subcutaneously or intravenously,” notes Karry. “While clearly, oral delivery of these would improve patient compliance and avoid injection-related injuries and illnesses, the stability of large therapeutic molecules in the gastrointestinal (GI) tract remains a significant challenge, mainly due to the inability to protect therapeutic proteins from the body.”

	Although many attempts have been made to develop oral versions of biopharmaceuticals, such as insulin, the enzymatic and chemical degradation pathways in the GI tract are too problematic, confirms Shah. “However, delivering biopharmaceutical products orally remains the holy grail for this molecule class, and there are advances being made in nanoparticle drug delivery systems and advanced manufacturing technologies coming to the fore. So, more progress is expected in this area,” he says.

	Mueller-Albers concurs there has been a strong demand within the industry for excipients that can reliably control transit of biologic drug products through the GI tract. “There are many promising examples in the literature and in the start-up community to keep an eye on,” adds Karry.

	“Oral solids are likely to remain the dominant dosage form within the pharmaceutical market for the foreseeable future,” confirms Mueller-Albers. “Above all, we expect tablets and capsules will continue to remain popular for use across the entire spectrum of drug candidates due to cost-effectiveness, stability, and strong rates of patient compliance. However, OSD forms will continue to become more complex and personalized.”

	For Shah, the drug pipeline will continue to be healthy, with increasing numbers of smallâmolecule drugs being launched in the OSD sector, which is still considered to be the backbone of all medicines. “While OSD forms continue to remain an important part of the pharmaceutical industry, there is a continual drive to develop new drug delivery technologies, such as the use of nanotechnology for example,” he says. “On a manufacturing front, there seems to be a trend toward the application of continuous manufacturing technologies, improving processes for complex drug products, and introducing manufacturing technology for individualized and on-demand drug products.”

	Spray-dried dispersions have been ‘on point’ for many drug developers in recent times, according to Savla, who believes this trend will likely continue. “There is a significant percentage of poorly soluble molecules whose sub-optimal solubility is not adequately addressed by current technologies or excipients,” he asserts. “This unmet need will require advancements in novel excipients or polymers, and novel technologies.”

	Karry adds that cost-competitive manufacturing, increased use of functional coatings, dosage forms amenable for pediatric applications, and drug products with more than one API are all trends that have been identified and are anticipated in the future of global OSD forms. Adding to this list, Mueller-Albers and Shah raise the point that stronger collaboration between pharma and non-profit organizations or academia is benefiting drug development advancement and so should continue to be a promising trend.

	1. Future Market Insights, “Oral Solid Dosage Pharmaceutical Formulation Market: Emerging Markets of Latin America, APEJ and MEA to Collectively Hold over 45% Market Value Share: Global Industry Analysis 2012–2016 and Opportunity Assessment 2017–2027,” Report, July 18, 2017. 


	Vol. 43, No. 7
	July 2019
	Pages: 24–29

	When referring to this article, please cite it as F. Thomas, “Selecting a Solid Approach,” 

Several trends are driving change in oral solid‑dosage forms and giving rise to the requirement of ‘fit-for-purpose’ excipients.


Selecting a Solid Approach

The potentially devastating effects of endotoxins to humans have been widely reported. At sufficient concentrations in the bloodstream it is possible for endotoxins to cause irreversible side effects and even death in severe cases.  

	Found on the outer cell membrane of Gram-negative organisms, bacterial endotoxins are one of the most potent toxins known and strongly pyrogenic (fever-causing) substances, explains Allen L. Burgenson, Testing Solutions, Lonza Pharma & Biotech. “These toxins are harmless outside of the body and in the alimentary canal. They are extremely potent, however, once introduced in the bloodstream or intrathecally,” he says.

	“Bacterial endotoxins (also referred to as pyrogens) have the capacity to induce a high fever,” confirms John Dubczak, general manager, Microbial Solutions, Charles River Laboratories. “A large enough dose of endotoxin can lead to lung and kidney failure, intravascular coagulation, and a systemic inflammatory response that can lead to septic shock and death.” 

	As a result of the dangers of bacterial endotoxins, the importance of testing for them is plainly apparent, in the view of Victoria Watson, laboratory manager, Microbiology at Wickham Labs. “The importance of endotoxin testing is clear when looking at how susceptible and sensitive humans are to even minute amounts of endotoxin,” she says.

	“Bacterial endotoxins are ubiquitous in nature and are a menace for the manufacturers of all parenteral drugs and medical devices,” asserts Dubczak. “Not only are they everywhere environmentally, they are very difficult to remove once they are introduced into a finished parenteral product.”

	Introduction of these molecules can come from simple contact with contaminated parenteral devices or medications, notes Watson. “Ensuring that equipment and medication are free from endotoxins is particularly important when caring for vulnerable patients, including the elderly, patients in intensive care, and infants,” she says. “For example, sudden infant death syndrome has been linked to varying levels of bacterial endotoxin present in the bloodstream.”

	“In the early days of injectable pharmaceutical products, there was no method for testing for pyrogenic contaminants,” reveals Burgenson. “If a patient received an injection, there was a high likelihood that they would spike a fever, which at the time was termed ‘injection fever’.”

	It was the work of Florence Seibert and her team in the 1920s that brought forth the introduction of the Rabbit Pyrogen Test (RPT) (1), which was eventually incorporated into the 

) in 1942 as an official test, Burgenson explains. “The clotting of Limulus blood was noted for many years in injured horseshoe crabs,” he says. “Frederick Bang and Jack Levin discovered the enzymatic pathway causing the clotting of Limulus blood (2,3), and developed the Limulus Amebocyte Lysate, or LAL test.”  

	During the 1970s, pharmaceutical companies experimented with the LAL test and compared it with the RPT, finding that the LAL test was a more reliable and sensitive assay (4), and offered cost-efficacy for companies as there was no need to maintain rabbit colonies for product testing. “FDA took notice, and decided that, since LAL was derived from blood, it was a biologic subject to regulation under Section 351(h) of the Public Health Service Act, and subject to regulation and licensure by FDA,” confirms Burgenson.  

	“Since its introduction, the LAL test has become one of the most important tools used in the pharmaceutical industry,” adds Dubczak. “It has allowed for a level of bacteria and pyrogen monitoring that simply eluded manufacturers when the RPT was the only pyrogen test available. The LAL test has ensured the absence of pyrogens in raw materials, water for injection systems, in-process samples, and in the final products.”

	The LAL assay works via the reaction of the LAL reagent-an aqueous extract of blood cells from the horseshoe crab-with bacterial endotoxins and lipopolysaccharides. “There are currently three compendial bacterial endotoxin tests (BET) found in the 

 (gel-clot, kinetic chromogenic, and kinetic turbidimetric) that may be used to test injectable pharmaceutical products and implantable medical devices for release into commerce,” notes Burgenson. “There is also the endpoint chromogenic assay, which is a timed endpoint version of the kinetic chromogenic assay.” (See 

 for a list of the advantages and disadvantages of endotoxin testing methods.)

This method is the oldest of the three and the simplest, Dubczak explains. “The major advantage of the gel-clot LAL test is its simplicity,” he says. “It is easily learned and can be performed without expensive equipment.”

	The gel-clot assay works through production of a clot in the presence of endotoxins by cleavage of a coagulogen to coagulin, notes Burgenson. “This method can be performed as either a limits test or a semi-quantitative assay, giving a positive or negative result at the sensitivity of the lysate used,” adds Watson. “Dilutions are tested with lysate, and the endpoint is used to calculate approximate endotoxin level.”

	Despite the method’s advantages, such as interacting with fewer materials, thereby giving rise to a lower likelihood of results being affected by sample inhibition or enhancement, certain disadvantages have hindered its popularity. “The amount of time that is required to prepare samples using this process has made it less popular for use in raw material testing in some laboratories,” Watson says. “Additionally, the lysate sensitivities used in the gel-clot method are less sensitive than the quantitative methods.” 

	“Furthermore, the test does not allow for automation and data assimilation by computers, making it difficult to track and trend results,” adds Dubczak.

The KTA is one of the quantitative assays in which the measurement of absorbance versus endotoxin concentration is used to create a standard curve, explains Watson.

	“During the LAL-endotoxin reaction, the solution mixture becomes increasingly turbid as the gel begins to form,” adds Dubczak. “The time required for these turbidity changes to occur is inversely proportional to the amount of endotoxin present in the sample (i.e., more endotoxin requires less time). The endotoxin in a sample can be estimated by comparing the time it takes to reach a defined level of turbidity to the times obtained from a series of endotoxin standards (standard curve).” 

	Sensitivity can be higher with KTA over the gel-clot method, he asserts, and although it is possible for KTA to be performed in test tubes, it is more common to perform the assays on plastic, 96-well microtiter plates. “The spectrophotometers that are used to measure turbidity changes can be captured by the use of appropriate software, and the assimilated data are used to generate quantitative reports,” Dubczak continues. “Those same data can be uploaded to a LIMS database for tracking and trending.” 

	Watson adds that the most significant advantages of quantitative methods over the gel-clot method are the increase in sensitivity and ability to extrapolate results. “Being able to extrapolate quantitative results can be invaluable when testing raw materials because it can offer insights into potential sources of endotoxin contamination,” she states.

The third method, the chromogenic substrate test, is a further evolution of the LAL test. “Instead of cleaving coagulogen to coagulin, the same enzymes cleave a substrate-releasing para-nitroanaline (pNA), and a yellow color develops,” reveals Burgenson. “Similar to the turbidimetric assay, the time of color development to exceed a threshold is measured. The more endotoxin, the faster the substrate is cleaved, resulting in a deeper yellow color.”

	For Dubczak, these chromogenic tests have an elegant methodology and feature many of the advantages that are found with KTA, such as increased sensitivity and extrapolation of quantitative results. “Chromogenic tests are, however, more expensive,” he says. “The chromogenic substrate material requires months to synthesize and as such, is very expensive to manufacture.” 

	“The latest evolution of the LAL assay is the use of recombinant Factor C, derived from the DNA of a horseshoe crab,” says Burgenson. “The gene sequence for Factor C is inserted into cells and expressed in cell culture. This recombinant Factor C (rFC) is the same as the natural Factor C. The assay using rFC does not produce a gel, turbidity, or a yellow color; it produces fluorescence proportional to the amount of endotoxin in a sample. The more endotoxin in a sample, the more light is generated.”

	Another in-vitro alternative is the monocyte activation test (MAT), which was developed on the principle of the human immune system response, reveals Watson. “When challenged by the pyrogens entering the body or coming into contact with the bloodstream, the host’s innate immune defense mechanisms cause the monocytes/macrophages to produce prostaglandins and pro-inflammatory cytokines such as interleukin-1 (ILâ1), interleukin-6 (ILâ6) and tumor necrosis factor-α (TNFâα),” she says.

	Additionally, the RPT is also an option, although this should only be considered as a final option once the LAL in-vitro methods have failed, Watson notes. “RPT is generally used for highly complex products that interfere with the in-vitro methods, and for release of products that require full pyrogen evaluation in markets that do not accept MAT as an alternative,” she explains.

	There are some products, namely biological ones, that are exempt from the rabbit test as stated in US 21 Code of Federal Regulations (CFR) 610.13(b), clarifies Burgenson. Therefore, in his opinion it is prudent for the developer to look at every approach that may be able to help overcome any interferences with the LAL assay. Some formulations include a chelator (such as citrate), with a non-ionic surfactant (such as polysorbate) causing the endotoxin to be lost in the product formulation. “A magnesium chloride solution has been successfully used to overcome interferences by chelating agents such as ethylenediaminetetraacetic acid or citrate buffers. There are other proprietary products, such as Pyrosperse (Lonza) or a glucan blocker that have also been used.”

	If difficulties persist, however, Burgenson recommends the best course of action is to contact the LAL reagent manufacturer, so that the work can be done in partnership. “These manufacturers have seen all types of interferences many times over, and, therefore, should be able to help,” he says.

	As LAL assays are performed using an extract of blood cells from the Atlantic horseshoe crab, the prehistoric marine arthropod plays an important role in patient safety. “This animal is under legal protection,” emphasizes Watson. “Without this protection, the horseshoe crab population would be threatened.” 

	Dubczak concurs, highlighting the fact that reduction of animal use for pharmaceutical testing has been a well-established influencer of the industry over the years, which has seen the LAL in-vitro test replace the traditional RPT to prevent the use of hundreds of thousands of rabbits per year to test for product safety and contamination. The LAL test is an animal-derived test, meaning the animal itself is not tested upon. “The horseshoe crab’s blood is collected only to a point where the crab stops bleeding as part of a natural mechanism to protect itself,” he notes.

	Additionally, there has been much work and commitment by manufacturers of the LAL reagent to conserve the horseshoe crab. “Work has included sustainability partnerships to enhance the horseshoe crab population along the mid-Atlantic shores,” says Watson. “Such projects have focused on increasing the survival rate of the horseshoe crab in early stages of life. Eggs are collected, and the crabs are grown in predation-free, controlled environments then released into their natural environment when older and stronger.” 

	Other projects include the “Just Flip Em” program where volunteers scan the beaches to rescue horseshoe crabs stranded on the beach on their backs, adds Burgenson.  Each year many thousands of stranded crabs are rescued.

	“Without the protection of the biomedical industry, these prehistoric creatures would surely become endangered, if not extinct. For this reason, it is critical that we serve as advocates for the humane treatment of these animals and strive to achieve balance between our need for this valuable material and the life of the animal that provides it,” stresses Dubczak.

	Raw material quality: Regulation required?

	“There has been an increase in raw material manufacturers requiring their products be tested for endotoxins,” notes Sophie Bell, section head for Bacterial Endotoxin and Cell Culture at Wickham Labs. “These requests come in usually due to pharmaceutical manufacturers requiring materials that do not contain detectable levels of endotoxins. The responsibility of the manufacturer is to source adequate materials for their products, so regulation of raw materials seems unnecessary; especially as different endotoxin specifications in end-products can affect the level of endotoxin contamination allowed in raw materials.”

	In agreement, Dubczak highlights that product regulations are designed to set forth the standardized expectations for finished drugs, biologics, and medical devices, and as such the responsibility of sourcing adequate raw material is that of the manufacturer. Using an example from FDA guidance on pharmaceutical good manufacturing practices (5), he states that it is clear that regulators expect the sound application of science and associated risk-based rationales to be the basis for a product’s development and manufacturing process. 

	“For instance, manufacturers should determine the level of risk for both active and inactive raw materials, and there should be a comprehensive assessment of critical raw material formulations, ingredients of in-process buffers, and final product formulations,” he adds. “However, to place strict regulations on this process would be counter to the intent of this approach.”

	Furthermore, Bell emphasizes the point that raw materials are not the only source of endotoxin contamination in end products. “Manufacturing processes can equally be a source of contamination, so the requirement for endotoxin testing in the product is still necessary. Testing of products from the beginning, middle, and end of manufacture is still advised to ensure uniformity across the manufacturing process,” she says. “Products that can be terminally depyrogenated will not require as clean raw materials compared to those that cannot.” 

	Despite the fact that raw materials going into pharmaceutical products are not specifically regulated, drug manufacturers use the highest grade of raw materials obtainable, emphasizes Burgenson. “Many of these materials are USP grade,” he adds. “Manufacturers will test raw materials and purified waters for the presence of endotoxins, and determine if the raw material meets its specifications and is suitable for manufacturing use.”

	“What is important is that the quality of the raw materials used in production meet the standards appropriate for their intended use,” clarifies Dubczak. “Raw materials or reagents do require science-based evaluation to establish the presence or absence of deleterious endogenous or adventitious agents.”

 71 621–651 (1925).
	2. J. Levin and F.B. Bang, 

 115 337–345 (1964).
	3. J. Levin, P.A. Tomasulo, and R.S. Oser, 

 75 903–911 (1970).
	4. F. Pearson, “LAL Assay: Applications and Equivalence,” in 

Pyrogens: Endotoxins, LAL Testing, and Depyrogenation

, Marcel Dekker, pp. 148–155 (New York and Basel, 1985).
	5. FDA, “Pharmaceutical cGMPs for the 21st Century-A Risk Based Approach,” Final Report (September 2004). 


	Vol. 43, No. 7
	July 2019
	Pages: 38–42

	When referring to this article, please cite it as F. Thomas, “Putting Endotoxins to the Test,” 

It is important to adhere to current methods of endotoxin testing, on which the industry relies for process sustainability. 

The Importance of Endotoxin Testing

	Hot-melt extrusion (HME) is a well-known process within industry, being used since the 1930s, and more recently has found prominence in the pharma industry within the application of enhancing the bioavailability of APIs. As the industry is witnessing a surge in the number of poorly soluble drug molecules entering the development pipeline, techniques to improve solubility will inevitably continue to experience growth.

	To learn more about HME, its advantages, limitations, and recent advances, 

spoke with Michael Dennis, director of technical operations, science and technology, and Bill Huang, senior principal research scientist, formulation sciences, both from AbbVie.

Can you give a brief overview of HME and how it can aid in solubility/bioavailability enhancement?

Historically, HME was used to convert raw materials into a homogenous solid with a particular shape. In pharmaceuticals, it also enables dissolution of APIs into a polymer to form a matrix known as an amorphous solid dispersion (ASDs). ASDs achieve higher apparent solubility and faster dissolution for enhanced absorption of poorly soluble compounds (BCS Class II and IV).

	In an ASD, solute molecules are dispersed molecularly randomly within the amorphous carrier. This allows for a drastic significant increase in the apparent solubility and dissolution rate achieving high bioavailability and better human pharmacokinetic/pharmacodynamic performance. A rationally formulated ASD generates drug-rich amorphous nanodroplets that maximize the surface area of the compound for improved absorption when contacting the dissolution medium as the carrier dissolves.

	While this technology is gaining significant traction in the pharmaceutical industry, especially in the oncology therapeutic area, it is key for anyone developing in this area to have a solid understanding of HME or to partner with someone with a strong and long tenure in understanding its nuances to ensure timely entry into the market.

What are the advantages afforded by HME over other available technologies/solutions aimed at enhancing solubility/bioavilability?

A major advantage is that it does not use organic solvents. This significantly reduces or minimizes both environmental and safety concerns. In spray drying, an alternative method for manufacturing ASDs, for instance, organic solvents are required to dissolve the polymer and drug and then the solvents are removed during spray drying and a subsequent product drying step.  

	Other benefits of HME when comparing to other techniques, such as spray-drying, is that it offers shorter cycle times, a smaller footprint, and lower capital costs, which all add to its efficiency. Moreover, it is inherently a continuous unit operation, allowing fast development and scalability. HME is well placed to serve as an effective anchor for an integrated continuous manufacturing line, whether that means sequencing a continuous blender to the extruder or sizing and compressing unit operations downstream.

	A well-developed ASD formulation and HME process is robust and well controlled, enabling the production of consistent product quality both intra- and inter-batch. Furthermore, HME provides an option to formulate drug products for molecules which have zero or limited solubility in organic solvents. 

Are there specific limitations of HME that should be considered?

Since HME depends on melting the polymer and drug, thermally sensitive API molecules and potentially some polymers may not be suitable. Additionally, as a result of the inherent characteristics of BCS Class II and IV API molecules, it is challenging to attain high drug loading in many cases. Further, the choice of pharmaceutical grade polymers and surfactants that are suitable for HME is still very limited.

Could you highlight the most recent advances in HME?

Absolutely, there are numerous efforts being made by industry to advance HME. For example, the understanding of fundamental aspects of formulation and drug release has been dramatically improved in recent years, which is aiding HME product and process design and development. We have also seen industry embrace the rigorous application of physicochemical characterization tools that are helping in the understanding of the impact of physical and thermal properties of materials (constituent components as well as drug-polymer and drug-surfactant interactions) on HME processing and product characteristics. We are also seeing a surge in the use of one-dimensional and three-dimensional computational models to optimize HME processes, which is a result of computational power increases and more efficient algorithms for discrete element models and computational fluid dynamics.  Through this improved understanding, it is becoming easier to develop robust formulations and processes with reduced development time and costs.

	Various custom in-house modeling tools have been developed by companies, enabling scientists to select the appropriate polymers, surfactants, and drug concentration, which is supporting faster and more efficient drug development. Additionally, in recent years, there have been significant research efforts made by excipient suppliers to advance HME through the development of new polymer systems (e.g., hypromellose acetate succinate and graft polymers).

	In addition to HME processes being applied to traditional solid oral drug products, they are also now being used in the formulation of biodegradable implantable products, such as poly lactic acid- and poly glycolic acid-based implants.

Experts from AbbVie discuss the advantages and limitations of HME for enhancing bioavailability of poorly soluble APIs.

Considering Hot-Melt Extrusion

	Supply chain security has been long deliberated and extensively scrutinized within the pharmaceutical industry. Much of the attention around supply chains has been focused on the later stages. However, as the industry shifts and more challenges become apparent, particularly with non-cGMP intermediates-early intermediates (EI)-there has been a drive to ensure greater security across earlier parts of the supply chain as well.

	To address the concerns around the supply and quality of EIs, Lonza Pharma & Biotech, headquartered in Switzerland, launched an initiative for small-molecule APIs (1). Through this initiative, the company will use its chemical production facilities located in Visp, Switzerland, to offer customers an integrated supply chain. Pharmaceutical Technology Europe spoke with Sean Diver, director of business development at Lonza Pharma & Biotech, to find out more about the changing supply chain security landscape.

What are the current challenges with the EI supply chain?

In recent years, the reliability of supply of materials, as well as the price, have become far less stable, and this has forced customers to re-evaluate the value of the supply chain, including the non-cGMP intermediates or EIs. The unstable supply largely comes from the over-dependence on regional supply of non-cGMP materials and increased regulations to address quality and environmental concerns in the regions that traditionally supply materials.

Why has there been such an industry trend towards outsourcing of EIs and how has this impacted the supply chain?

Over the past 15 years, Western producers have largely focused on downstream cGMP manufacturing while raw materials and non-cGMP intermediate production have shifted towards the East, into China particularly. In the late 1990s and early 2000s, Chinese producers invested in chemical capacity that produced materials at very low costs. This additional capacity at lower costs shifted the supply/demand balance significantly, provided tremendous excess capacity, and made it difficult for Western producers to compete based on price. The dependence on regional Eastern suppliers has been widely accepted and utilized until recently. 

	However, due to shifts in the supply of materials, closures of significant capacity, and considerably higher pricing, the supply of EIs has shifted. As security of supply is driving the decisions around these materials, and price is not as strong as a driver, companies are broadening their horizon related to the source of supply. Today we are seeing companies working more broadly with Western producers.

What are the potential ramifications later in the chain if EI batches are found to be of poor or inconsistent quality?

The implications of poor or inconsistent quality EIs are severe, as the downstream quality of advanced intermediates, API, and drug product could easily be impacted. It is critical that EIs be manufactured with a well-defined process, and with changes closely monitored and controlled. The impurities from these EIs can very easily make their way to the end product. 

	A recent example of this is seen in the need to recall many sartan products in Europe, as well as the United States, due to impurities from an EI. In addition, correcting these quality-related problems can cost a lot of money, time, and most importantly, supply of life-saving medicines to patients. Speaking generally, when products are recalled due to the API being contaminated at one site, overreliance on a small set of producers can lead to supply shortages. In more extreme cases, such as if one site is the single source of a drug, a global shortage of a drug could occur.

How can manufacturers improve the security and quality of EI supply?

Embracing the supply chain as a ‘value chain’ can help ensure robustness, quality, sustainability, and innovation of API supply. Total cost of ownership philosophies need to include the EIs to address the security of the value chain.

	Companies can benefit from engaging suppliers with assets for cGMP production as well as non-cGMP materials. Going beyond the traditional Eastern region and engaging with Western partners, such as those in Europe, with deep experience in quality management systems, technology, manufacturing, and innovation for the pharmaceutical industry can increase quality systemically and provide the manufacturing and delivery services needed to ensure uninterrupted supply and availability of critical medicines for patients. The right suppliers can enhance the value chain by engaging the appropriate technologies in the appropriate facilities that drive compliance and competitiveness. 

In Europe, we are seeing a drive to improve supply chain security through the falsified medicines directive (FMD). Has this revised regulation impacted companies’ decisions on procurement of ingredients, in your opinion?

The FMD has created a more rigorous system to protect and regulate the supply chain, manufacturing process, and delivery of medicines. In essence, the directive will influence companies to continue to seek data-rich and technology-driven solutions that optimize, streamline, and unlock value within their supply chains, starting from the very initial upstream phases including extraction and procurement of ingredients.

Are there other regulatory challenges impacting the supply of EIs?

Enhanced approaches to environment, health, and safety (EHS) regulations has weakened the value of the supply chain as costs have risen in certain regions. In China, increasingly rigorous EHS requirements and substantial environmental taxes have put pressure on manufacturing facilities and even shut down a number of them due to poor environmental conditions. With such a reliance on supply of materials from China, customers’ supply chains have seen substantial price increases or have been left with no qualified suppliers of non-cGMP materials due to environmental regulatory requirements. This is why European and US suppliers are now being reconsidered for supply of these materials as rigorous EHS programmes have been in place and proven for many years.

Over the coming five to 10 years, what may we expect to see trending, in terms of the EI supply chain?

The unstable supply of EIs and new regulations will require pharmaceutical companies to transition from a supply chain mindset to that of a value chain, where companies can extract and unlock value-such as data, increased quality protection, and responsiveness-from every facet. Additionally, the Western chemical capacity must re-emphasize upstream manufacturing and invest in local assets, or their own assets, to better distribute the global supply of APIs, and intermediates to stabilize sustainability, cost, and quality of supply.

	In summary, the industry has seemed to learn a lesson that being overly dependent on one region for global supply has serious risk. Pharmaceutical supply chains seem to be thinking about region-by-region strategies as well as global ones, and find tremendous value in it. In the future, look for supply of materials to come from sources that have a culture of compliance, innovation, and efficiency. The supply of these EIs will be treated more strategically than they have been over the last era. 

	1. Lonza, “Lonza Launches Early-Intermediates Supply Initiative for Small-Molecule APIs,” Press Release, 14 Sept. 2018. 


	Vol. 31, No. 6
	June 2019
	Pages: 40–41

	When referring to this article, please cite it as F. Thomas, “Filling the Early Intermediate Security Gap,” 

With an increased focus on the supply chain security of non-cGMP intermediates, companies need to re-emphasize upstream manufacturing.

Filling the Early Intermediate Security Gap

	Recently, it was announced that several pharma companies, namely Novartis, Sanofi, Otsuka, and Pfizer, were to be strategically aligned with Verily, an Alphabet company, in an initiative aimed at engaging more patients and clinicians in clinical research (1). As clinical trials can sometimes prove to be a sticking point for drug developers, in terms of dwindling or even lacking participation numbers, could this initiative offer a paradigm shift by making trials more accessible?

	Project Baseline was originally launched in 2017 by Verily with the goal of closing the gap between clinical research and patient care. Partners of the original project included Duke University School of Medicine, Stanford Medicine, the American Heart Association, and Verily’s sister company, Google. Technology and tools, including DNA tests and wearable devices, were developed and built for the project, and were used to map out human health.

	Now, Verily is looking to enrol more patients within its registry and the aforementioned industry partners will leverage the Baseline Platform-an endâto-end evidence generation platform-to support their clinical studies across a variety of therapeutic areas. The ultimate aim is to create patient-centric trial programmes that will deliver ‘real-world evidence’ for the companies, which is certainly seems to be a buzz term currently experiencing enthusiasm within the bio/pharma sector.

	“Evidence generation through research is the backbone of improving health outcomes. We need to be inclusive and encourage diversity in research to truly understand health and disease, and to provide meaningful insights about new medicines, medical devices, and digital health solutions,” said Jessica Mega, chief medical and scientific officer, Verily, in a press release (1). “Novartis, Otsuka, Pfizer, and Sanofi have been early adopters of advanced technology and digital tools to improve clinical research operations, and together we’re taking another step towards making research accessible and generating evidence to inform better treatments and care.”

	However, reinventing the clinical trial wheel is not necessarily a brand-new concept. There has been a plethora of news items in recent years on how various companies or research bodies are implementing technological solutions to help accelerate the costly and timeâconsuming clinical trial process. 

	The difference that perhaps makes Project Baseline stand out from the crowd is the ability of Verily to lean on its sister company, Google, to engage with patients using tools such as personalized advertising functionality for engagement. For example, if a patient performs a Google search for treatments within a specific therapeutic area, an ad that offers enrolment within a clinical trial from Verily could be placed on the web page being viewed by said patient.

	“Our scientific knowledge has exploded over the past generation, but efficiently bringing these new breakthroughs from lab bench to patient requires us to greatly improve the way we conduct these complex clinical trials,” said Lionel Bascles, global head of clinical sciences and operations, Sanofi, in a press release (1). “Project Baseline will allow us to better recruit appropriate patients and more efficiently integrate data for a greater understanding of diseases, reconnecting trials to our patients’ healthcare journeys.”

	So far, the project is solely focused on the United States, but the company is hopeful to expand it out on an international scale. However, there may be some bumps in the road ahead for these plans, as European data protection could prove a challenging obstacle to overcome.

	Google is already facing investigation by the Irish Data Protection Commission (DPC) surrounding the way it uses personal data for targeted advertising (2) and whether or not this adheres to the 2018 General Data Protection Regulation, which may mean Europe is not as attractive as other regions for rollout of Project Baseline. 

	It will be a case of waiting and watching as to whether data protection becomes an issue for the initiative on the whole and whether the global uptake of stricter data regulations, a possibility given the political draw such issues can have, hampers the potential this project may have on accelerating the lab bench-to-bedside timeline of drugs in development.

	1. Verily, “Verily Forms Strategic Alliances with Novartis, Otsuka, Pfizer, and Sanofi to Transform Clinical Research,” Press Release, 21 May 2019.
	2. DPC, “Data Protection Commission Opens Statutory Inquiry into Google Ireland Limited,” Press Release, 22 May 2019.

	When referring to this article, please cite it as F. Thomas, “As Easy as ABC?,” 

Big Pharma is partnering with Alphabet company, Verily, to modernize clinical trials and accelerate time-to-market for drugs.