Overcoming Bioavailability Challenges In Oral Formulation Development

By Sundeep Sethia, Ph.D.

Poor solubility of drug substance is a major challenge in early oral formulation development. When a drug candidate has poor or low solubility, this can have a major impact on the ability of a drug to be absorbed into a patient’s gastrointestinal tract. These compounds are classified as either Biopharmaceutical Classification System (BCS) Class II, meaning they have high permeability and low solubility, or as BCS Class IV, which are compounds with low permeability and low solubility. With nearly 90 percent of the developmental pipeline drugs consisting of poorly soluble molecules¹, formulation experts must be prepared to address this obstacle by applying various approaches to improve an API’s pharmacokinetics. The development process needs to be focused on improving the rate of dissolution and maintaining the supersaturated solubility state at the site of absorption. If it is not, it can lead to delays in development or even clinical trial failures, leading to added costs.