Studies on Absorption and Excretion of Drug. VIII. The Release Rate in vivo of Antipyretic and Analgesic Drugs from Commercial Sugar Coated Tablets

The drug release property from the six commercial sugar coated tablets which contain antipyretic and analgesic igredients were estimated from comparison of the urinary excretions after the oral ingestion of tablets and the dissolved solutions in human. The igredients are sulpyrine, aminopyrine, phenacetin, bucetin, N-acetyl-p-aminophenol, salicylamide and Al-acetylsalicylate. The over-all mean value of the time of fifty per cent drug release in the gut was 1.62 hr. The mean availability was as good as 96.2 per cent. The release rate of Al-acetylsalicylate was slower than the others in statistically significant and also the instances of poor availability of the drug were observed. The merits of the convolution equation method for the estimation of release rate in vivo were demonstrated in the case of the compounded drug.