Biopharmaceutic evaluation of etofylline clofibrate and its drug formulation.

The biopharmaceutic criteria of Duolip and its active principle, 1-(theophyllin-7-yl)-ethyl-2-[2-(p-chlorophenoxy)-2-methylpropionate] (etofylline clofibrate, ML 1024), are described. ML 1024 was found to be practically insoluble in water at pH values ranging from 2 to 7.4 and in human serum. A very low dissolution rate of the drug from the capsule preparation was found in artificial gastric and intestinal fluid, along with little cleavage to the individual components clofibric acid and etofylline. The particle size was mainly less than 40 micrometers. For the classification of granules the granule size, the angle of repose (tan alpha), the flow time, the stamp volume and the packing factor were determined.