ABSTRACT

Considerable evidence that drug bioavailability is influenced by food, in conjunction with the poor and erratic bioavailability of sparingly soluble drugs, serve as a stimulus in the research field for examining new formulations that may provide more consistent absorption. The in vitro and in vivo availability of freeze dried and spray dried drug-milk products were studied under “high-fat meal” conditions. In vitro drug release profile showed that though the freeze-dried product released the maximum drug, release was sporadic. Spray dried product increased the drug release but lesser than freeze dried products. The spray dried product also showed consistent release of drug. The interaction of theophylline with milk fat influenced all pharmacokinetic parameters such as, the action of theophylline being observed to be sustained for a longer period. Spray dried product also increased the rate and extent of absorption. The main feature of this system is that the drug-milk product is regenerated by adding water to the freezedried and spray dried drug-milk formulation just prior to administration. Thus, a drug-milk product with most of the drug in solution is effectively ingested. One important factor which has shown effect on drug bioavailability is the potential influence of regenerated fluid volume on drug absorption.