Enhancement of the dissolution rates of poorly water-soluble drugs by water-soluble gelatin.

The dissolution behavior of several acidic and basic drugs from kneaded mixtures with water-soluble gelatin have been studied in comparison with that of the drug alone. The results revealed a significant increase of dissolution rate of drugs from kneaded mixtures. The water-soluble gelatin showed little interaction with any of the drugs in solution or in the solid state. Interestingly, the contact angle of the kneaded mixture was remarkably decreased compared with that of the drug powder and was found to be almost the same as that of water-soluble gelatin powder. Thus, the enhanced dissolution rate of the drug caused by water-soluble gelatin was explained by the improvement of wettability of the drug by water.