Abstract
Stability of nifedipine preparations was studied using samples of 5 brands. The samples were kept in 2 different conditions: one group exposed direct to the sunlight and the other under fluorescent light in or out of a blister pack. Changes in appearance, weight and content were examined of the samples kept under the direct sunlight for 3 months and those kept under the fluorescent light for 6 months. GLC, as well as TLC, methods were used for the analysis of nifedipine.
Among the samples taken out of a blister pack and exposed to the direct sunlight, those in lightproof red capsules were stable with little loss in content. No changes were observed in the samples kept in a blister pack under the fluorescent light. However, in some of the sampies out of a blister pack under the fluorescent light, oozing out of nifedipine on the surface of capsules and a considerable content loss were observed as compared with the samples out of a blister pack under the direct sunlight. These results suggest that loss in nifedipine content in soft capsules be not only due to the influence of light.
