Unlocking the full potential of many therapies hinges on effective absorption in the lower GI tract. Yet, delivering fragile APIs to the right location is no small feat. In this insightful series, we dive into real-world challenges and innovative solutions for the precise delivery of acid-sensitive APIs—helping you stay ahead in drug development.
Question: How do you develop an oral drug formulation that will protect an API in the acidic stomach environment and dissolve easily in pH of 6.8?
Answer: Achieving acid resistance and protecting acid-labile active pharmaceutical ingredients (APIs) from the acidic gastric milieu, with a typical pH in the range 1.5 to 3.5, has traditionally required the use of enteric-coated capsules. This meant an additional manufacturing process, post-filling, to apply an enteric coating, often involving the use of heat and solvents. Though these coatings can offer effective acid resistance, the solvents and heat treatments themselves can be deleterious to the integrity of APIs.
To overcome this drawback, Lonza developed a unique hypromellose / hypromellose acetate succinate (HPMC/HPMC-AS) bi-layered polymer capsule that does not require secondary treatment. Capsugel® Enprotect® capsule achieves full compendial acid resistance without the need for secondary enteric coating of the capsule. This not only increases manufacturing speed and efficiency but also ensures that the integrity of the API payload is maintained. The entire small intestine has an extended area for absorption, from the duodenum to the distal ileum, with a pH typically in the range 6.5 to 7. To ensure that the API is released at the optimal site, the dosage form needs to use a capsule that can be formulated to dissolve at the pH most correlated with the optimal release site.
Capsugel® Enprotect® capsules offer both standard dissolution profiles and customized dissolution options through our Innovaform® Accelerator formulation center of excellence, enabling precise API targeting and release. In conclusion, capsule options are available that can resist the acidity of the stomach and dissolve at a pH of 6.8. These either use secondary enteric coating – involving a two-step manufacturing process, and consequent API exposure to heat and solvents – or the unique intrinsically enteric polymer bi-layered Capsugel® Enprotect® capsule.
Learn more about the Capsugel® Enprotect® capsule and how it could help solve your oral-dosage challenge.