Dissolution profiles for cytochrome c in capsule containing enteric coated granules and in enteric coated tablet were investigated. The studies were carried out by using the JP X dissolution method II (paddle method) with agitation at 100rpm in 2nd fluid of JP X disintegration test.
A marked difference of dissolution profiles between two dosage forms was observed. The capsule achieved nearly 100% dissolution in 40min and the mean dissolution time (MDT) of cytochrome c in capsule was estimated as 16.6min. The tablet showed a poor dissolution profile and achieved only 72% dissolution in 40min. The MDT of cytochrome c in tablet was estimated as 22.2min. The contents of cytochrome c in capsule and tablet were determined by extraction with distilled water and phosphate buffers. Cytochrome c in capsule was completely extracted into distilled water and phosphate buffers and the content of cytochrome c in capsule was 105% of the labeled amount. A large difference between distilled water and phosphate buffers was recognized in extraction from tablet, and the content of cytochrome c in tablet was closed to the labeled amount by extraction with 1.0M phosphate buffer. The results suggest that cytochrome c may probably be adsorbed to the additives of the tablet.