Studies on Dissolution Tests of Soft Gelatin Capsules. V.1) Rotating Dialysis Cell Method2)

Abstract

A dissolution test was performed on a soft-gelatin capsule containing tocopherol nicotinate (TN) diluted with vegetable oil. The test methods were the paddle (PD) method described in the Japanese Pharmacopoeia (JP) and a rotating dialysis cell (RDC) method by which the sample is disintegrated inside a rotating cell covered with a filter and the contents are expelled from the cell into a solution outside. TN is practically insoluble. In the aqueous test solutions (pH 1.2 and 6.8), low dissolution rates were obtained by both the PD and RDC methods. However, we obtained a high dissolution rate by adding n-octanol, which has often been used for the measurement of drug partition coefficient, as a modification of the RDC method which has many factors controlling the drug dissolution. By examining the changes in the blood concentrations of TN after administration of the TN soft-gelatin capsule to humans, we established a relationship between the in vivolin vitro findings. © 1994, The Pharmaceutical Society of Japan. All rights reserved.