Making drugs more bioavailable
C&EN, 25 September, 2022
Hints of new science emerge in a field of growth for pharmaceutical services firms.
Earlier this year, Hovione announced a partnership with a Danish firm that has developed a whey protein–based excipient meant to enhance spray-dry dispersions. Hovione saw in Zerion Pharma’s Dispersome a means of advancing its services addressing bioavailability in drug formulation. Zerion, launched in 2019, saw a clear advantage in teaming with a well-established pharmaceutical services firm recognized as a leader in spray-drying services.
A few months later, Nanoform Finland, a nanoparticle engineering specialist based in Helsinki, announced a partnership with the specialty drug firm Pharmanovia, which will apply Nanoform’s nanoparticle technology and formulation know-how to improve the bioavailability of drugs in its product line.
Zerion and Nanoform are among the growing number of firms trying to deal with problems related to drug bioavailability. Their approaches are welcomed by industry observers, given the increased urgency of such problems and the relative sparsity of technological innovation.
Bioavailability, a measure of the portion of an active drug substance that enters the body’s circulation and affects the drug’s target, may not be the steepest challenge faced by developers of new therapeutic compounds. But it may well be the most pervasive. By many estimates, 70–90% of new small-molecule oral drugs have problems related to solubility and absorption.
These problems have been exacerbated in recent years by the increasing complexity of drug molecules, especially in the oncology arena, according to Peter Bigelow, president of xCell Strategic Consulting. The speed with which innovators need to move forward in development has also resulted in a growing market for particle engineering and design, he says.
“Because speed is kind of the most important objective of so many of these programs, changing the chemistry is not something they have the luxury to do,” Bigelow says. “A sponsor company will say, ‘I can’t take a year off to come up with a new synthetic route. So you’ve got to make this route to work.’ ”
Bioavailability services first emerged among providers specializing in formulation rather than at contract development and manufacturing organizations (CDMOs), whose primary service centers on the manufacture of active pharmaceutical ingredients (APIs). But the field has shifted over the last decade with the broadening of service offerings among CDMOs and the emergence of a one-stop-shop approach.
BEYOND API MANUFACTURE
One of the most popular techniques for improving bioavailability is spray drying, a method for converting poorly soluble APIs into an amorphous dispersion by dissolving the API and a polymer exipient in an organic solvent and evaporating the solvent with heated gases. Hovione was an early adopter, investing in its first spray-drying capacity in 2004, but not with an eye toward improving bioavailability of customers’ drug candidates.
“This is a good example of taking the right decision for the wrong reason,” says Guy Villax, who stepped down as CEO of the family-owned company earlier this year but remains on its board. “I was out in the market looking for business. I came across two inquiries that needed spray drying. We decided if customers were ready to make commitments, we were willing to invest.”
"To be successful you need more than the hardware." - Filipe Gaspar, chief technology officer
The contracts involved work on Captisol, a solubilizing agent whose manufacture required spray drying as an isolation technique. “There was nothing strategic in terms of addressing poorly soluble molecules,” Villax recalls. But as a result of those early contracts, Hovione was in position to provide solubility services—notably for hepatitis C drugs—as the market grew.
Hovione significantly increased its spray-drying capacity in 2009, when it acquired a Pfizer plant in Cork, Ireland, that included what at the time was the world’s largest solvent-based pharmaceutical spray-drying tower.
Other CDMOs have added services more recently. Fabbrica Italiana Sintetici (FIS) adopted spray drying in 2017, when it opened a new facility at its headquarters plant in Montecchio, Italy. FIS also provides micronization, a process of physically and mechanically breaking up drug crystals, and lyophilization, a freeze-drying means of manipulating particle size. Its sister company, Brenta, is a nanotechnology specialist offering formulation services that address API absorption and bioavailability.
“FIS is a drug substance manufacturer; we are not in drug product,” says Luca Parlanti, the firm’s marketing director, using industry terms for active chemicals and finished drugs. “However, we recognized the increasing relevance of particle-size solid-state technology in general. It is important for a provider like ourselves to offer a forward integration into areas that bridge drug substance and formulation.” Particle engineering is a method of addressing not only bioavailability but also processability, Parlanti says, “because solid-state properties may impact the flow of a drug in the formulation process.”
Lonza, one of the largest contract API manufacturers, has extended services into particle design via acquisition. The company acquired Capsugel, a formulation services specialist, in 2016, 3 years after Capsugel bought Bend Research, a leader in spray-dry dispersion services. The Capsugel deal also netted Lonza micronization services, but the Swiss firm recently divested assets, notably a plant in Quakertown, Pennsylvania, that was acquired by investors and set up on its own as Microsize.
Lonza announced last month that it would introduce X-ray powder diffraction technology, an analytical tool to improve jet-milling micronization, at its formulation services operation in Monteggio, Switzerland.
The company’s sale of the Pennsylvania plant is the latest transaction for a business dating back to 1994, when it began as Powdersize. It changed hands twice—purchased first in 2013 by Microsize’s current CEO, TJ Higley, and then by Capsugel. Higley left after the Lonza acquisition and returned to head the company this year.
Higley says Microsize maintains its heritage of micronization, which he characterizes as a first line of attack in addressing bioavailability. He says the advantages of micronization include ease of process development and scale-up, an increase in particle surface area, processing at ambient temperatures, and overall low cost compared with its primary alternative, spray drying.
Higley sees Microsize in a strong position. “The market is capacity constrained,” he says. “There is plenty of work out there, plenty of demand.” Some drugmakers have responded by setting up in-house particle design centers, “but there are huge limitations because people aren’t experts at it.” Nor are the in-house facilities typically capable of processing APIs from gram scale up to clinical and commercial scale, he says. “I would say people are bringing early, small-scale micronization in-house,” Higley says. “So, at some point they are going to need to outsource.”
Catalent, another big services firm that has amassed particle design services, has bioavailability assets that date back nearly a century. “Catalent has been in the business of increasing oral bioavailability for oral delivery of active ingredients since the RP Scherer business was formed in 1933,” says Cornell Stamoran, vice president of corporate strategy, referring to a company formed by Robert Pauli Scherer, inventor of the rotary die encapsulation process used to formulate soft gelatin capsules. “I have a lab notebook in my office of one of the first R&D people on their second or third project, which was increasing bioavailability of fish oil.”
Scherer was purchased in 1998 by Cardinal Health, which spun out its pharmaceutical services business as Catalent in 2007. Catalent has since acquired Pharmatek Laboratories, a drug services firm with spray-drying capabilities, and Juniper Pharmaceuticals, an expert in spray drying, nanomilling, and hot-melt extrusion—a method of melting a substance and forcing it through a die to form a new structure; it is widely employed in plastics and has more recently been adapted to pharmaceutical particle design applications.
Thermo Fisher Scientific, a pharmaceutical services firm that took a leadership position in formulation services with the acquisition of Patheon in 2017, has also built a portfolio of bioavailability technologies. It added small-scale spray-drying dispersions with the purchase of Agere Pharmaceuticals in Bend, Oregon, which was formed in 2016 by the former CEO of Bend Research. Thermo Fisher added commercial-scale spray drying at a plant in Florence, South Carolina, shortly after acquiring the site from Roche in 2016.
The Roche site also added micronization to Thermo Fisher’s tool kit. And the company invested in small-scale hot-melt extrusion capacity in Bend before scaling up the technology at its plant in Cincinnati.
Both Catalent and Thermo Fisher have introduced systems to assess the most effective approach to formulation in early-stage drug development, including the selection of techniques to address bioavailability. Catalent has a program, OptiForm, that is based on a predictive modeling regimen it acquired from GSK in 2010. And Thermo Fisher introduced a predictive modeling tool, called Quadrant 2, that guides drug developers in choosing particle design approaches.
Meanwhile, there are indications that improved approaches are coming to the market. Based on research that began at the University of Copenhagen, Zerion has developed a technology that uses proteins to increase small-molecule drug solubility and that constitutes an alternative to known polymer excipients in spray-dry dispersion applications. “We researched all sorts of different materials, including mesoporous silica, amino acid peptides, and cellulose nanofibers and eventually also proteins,” says Korbinian Löbmann, who is now Zerion’s chief science officer. The firm zeroed in on proteins.
“We tested all the different proteins we could get our hands on, and out of all that research we identified that whey proteins worked particularly well not only for amorphous stabilization but also solubility enhancement,” Löbmann says. The whey protein also allowed significantly higher drug loading—up to 70% of the weight of the particle as opposed to an industry standard of 30% at the high end.
Researchers filed a patent on behalf of the university and formed Zerion. The company has a partnership with Arla Food Ingredients, a specialist in whey protein processing that has developed a means of purifying β-lactoglobulin from whey protein isolate, for which the largest market is infant formula.
Interest in the protein excipient Dispersome has materialized, says Zerion CEO Ole Wiborg, and the firm now has contracts with four major drug companies. And then there is the partnership with Hovione.
“We were approached by Hovione, and this was very positive,” Wiborg says. We could see there was a lot of synergy between what we offer and what Hovione offers. And Hovione is, if not the best, then one of the best at spray-dry amorphous dispersion.”
Moreover, Wiborg says, Hovione opens the door to small and midsize companies, the primary pharmaceutical innovators, which have been more difficult to identify and connect with than the majors.
Hovione also sees benefits for both partners, whereby it gets access to a sophisticated new technology and boosts market access for a start-up, says António Dinis, Hovione’s director of sales and marketing. The deal establishes Hovione as “the sole partner for promoting the technology into the pharma marketplace,” he says.
The arrangement is the first in which Hovione has gained new technology through a partnership, he adds. It may not be the last, given the industry’s problems with bioavailability. “Hovione is actively pursuing opportunities to enhance our technology offering to address these problems,” Dinis says. “Hovione will from now on be much more open to partnering with companies that help us bring more solutions to our customers.”
Nanoform, which spun out of the University of Helsinki in 2015, has innovated a nanocrystalization approach to particle design by employing supercritical carbon dioxide. The company’s controlled expansion of supercritical solution technology produces particles as small as 10 nm but more typically within a range of 100–300 nm without the use of solvents, excipients, or polymers.
The technology works by dissolving APIs in supercritical CO2 and controlling the pressure through a flow process to achieve supersaturation, which leads to crystallization or precipitation, according to Christopher Worrall, Nanoform’s vice president of US business development. The reduced size increases particles’ surface area, thereby increasing the dissolution rate and thus bioavailability.
Nanoform signed its first contract last year for a drug produced according to the Finnish Medicines Agency Fimea's good manufacturing practice standards and has a goal of signing three such contracts this year.
TWEAKS AND TRANSFORMATION
Despite the paucity of wholly new approaches to particle design, efforts are underway to improve workhorse approaches such as spray drying. Deanna Mudie, a principal scientist at Lonza’s operation in Bend, says Lonza has been experimenting with methods to facilitate amorphous dispersion of so-called brick-dust APIs—poorly soluble drugs with high melting points.
“When drugs have poor solubility in organic spray-dry solvents, you end up with a very low throughput and also high organic solvent usage, which of course is not environmentally friendly,” Mudie says.
One approach is to install a heat exchanger before the spray-drying step to increase a drug’s solubility in an organic solvent. The company is also applying environmentally friendly solvents, such as acetic acid, to processes to reduce the use of standards such as acetone, methanol, and in some cases environmentally impactful solvents such as dichloromethane.
“In general, we have had that focus on improving spray drying over the last 5 years,” Mudie says. “There is a big push because we have seen a trend toward the brick-dust APIs.”
While CDMOs have tended to bring on board tried-and-true methodologies for addressing bioavailability, adding such services can have a transformative impact. At Hovione, research in particle design has grown from a small research group of five chemists in 2005 to a multidisciplinary division with 70 scientists, including chemists, chemical engineers, biologists, and mathematicians.
“To be successful you need more than the hardware,” says Filipe Gaspar, Hovione’s chief technology officer and head of its particle design group. “You need the software, the people, the knowledge in R&D, the marketing effort. It is the coordination of a lot of disciplines.”
And innovation in particle design, as well as the customer engagements that arise as a result, aims CDMOs toward broader activity in services downstream from API manufacturing. Last month, Hovione announced the start of a new continuous tableting operation at its site in Loures, Portugal. Dinis sees a continuity in the growth of services. “A hundred percent of the powder we process in tableting comes out of spray drying,” he says. “If we weren’t working in spray drying, we would not be involved in tableting.”