Use of soybean protein for controlled release of drugs administered orally.

The influence of soybean protein (SBP) on the release of drugs from per-oral formulations was investigated, using dl-propranolol as model drug. Directly compressed tablets of SBP/lactose containing more than 40% of SBP did not disintegrate and kept their shape for long periods. Then, dissolution tests (JPX) were carried out with similar tablets containing dl-propranolol hydrochloride as active ingredient. The dissolution profiles showed sustained release of the drug, the dissolution rate being prolonged with increasing amounts of added SBP. Dissolution was affected by the pH of the test medium and accelerated by addition of pancreatin to the test medium. Our results suggest that interaction between SBP, drug and lactose may influence the dissolution rate. Dissolution was unaffected by varying compressional pressure (100-300 kg/cm2) in the preparation of tablets.