Similar or not? Comparison of dissolution profiles of different hydroxypropylmethyl cellulose (HPMC) capsules

Abstract

The effect of using different HPMC hard capsule shells on the in vitro dissolution profile of acetaminophen powder was investigated. Use of HPMC capsule shells from different manufacturers resulted in different in vitro dissolution profiles. These differences were unrelated to the presence or absence of a gelling agent (carrageenan) in the capsule shells when potassium was absent from the dissolution media. Even though these differences can be significant from a regulatory point of view, they do not translate into differences in the in vivo performance. This is because, in some cases, the similarity criterion of f2 ≥ 50 is too strict.