By Otilia Koo
As pharmaceutical scientists, we are constantly faced with the need for innovation and breakthroughs in formulation design. One way is to try and use novel excipients in order to ensure successful formulation and drug delivery. However, novel excipients have regulatory challenges and may involve longer time and greater resources in development. As a result, there are limited options in excipient selection, and we may have to look to new applications of existing excipients to address challenges like low bioavailability, food effect, and poor stability issues. As an illustration, we are very familiar with the established chemistry and safety of hypromellose (also known as HPMC = hydroxypropyl methylcellulose). Recent advancement of the HPMC chemistry has led us to HPMC-AS (hydroxypropyl methylcellulose acetate succinate), which is a mixture of acetic acid and monosuccinic acid esters of HPMC thus providing good hydrogen bonding potential. As a result of this enhancement, HPMC-AS has been widely used as a solid-dispersion carrier for bioavailability enhancement of poorly soluble compounds. Furthermore, if we select the right grade of HPMC-AS, it also can be applied for an enteric coating for delayed release formulations. This is a good example of innovation in excipient design and modification for new formulation innovation.
In a mini-symposium session at the 2014 AAPS Annual Meeting and Exposition, Next Generation Formulation Design: Innovations in Material Selection and Functionality, attendees will learn about innovations in material selection and functionality of existing excipients for new applications. You will hear different ideas from the regulatory, industry, and excipient supplier perspectives on how we can achieve greater functionality utilization and what issues may arise.
New applications of existing excipients can include new routes of administration, increased levels of incorporation (beyond those in the Inactive Ingredient Database), new grades of existing excipients, coprocessed excipients, and new understanding of the potential for excipients to influence/modify physiological processes. Regulatory impact when new uses of an existing excipient are proposed will be discussed. Several examples of new uses of existing excipients will be reviewed. The excipient innovator and supplier’s perspective, and the novel applications of existing excipient polymer chemistries to overcome drug delivery and stability challenges will be presented. Finally, it will be interesting to hear how we can use porous inorganic excipients as carriers for amorphous solid dispersions as a new technology. The design, processability, and characterization of mesoporous excipient-based amorphous solid dispersions will illustrate where this novel technology fits into the existing toolbox of formulation technologies for poorly water soluble drugs.
The panel of speakers includes:
- Richard Moreton, Ph.D., is a partner in FinnBrit Consulting and a member of the USP Expert Committee—Excipient Monographs for the 2010–2015 Revison Cycle. He is also a past chair of Chair of IPEC-Americas and is still active on several IPEC committees including GMP, QbD, and Excipient Composition.
- Thomas Durig, Ph.D., is senior director, Pharmaceutical & Nutrition Specialties R&D at Ashland, Inc., where he is responsible for new product and new applications development.
- Irina Kazakevich, Ph.D., is an associate principal scientist in the parental formulation group, Merck Research Laboratories, where she supports multiple development projects.
As we all try to find new ways to innovate our formulation designs, the sharing of experiences in this mini-symposium on Thursday, November 6, will definitely provide you with ideas to take home.