Sustained urinary excretion of sulfamethizole following oral administration of enteric coated microcapsules in humans

Microcapsules containing sulfamethizole were prepared by coacervation of carboxymethylethylcellulose, an enteric coating material, from ethyl acetate solution in the presence of polylactic acid. Release rates of the drug from the microcapsules in vitro were much slower than dissolution rates of the drug from tablets. The urinary excretion of the drug following oral administration of the microcapsules in humans was sustained over that of tablets. Pharmacokinetic analyses indicated sustained absorption following the administration of the microcapsules. The extent of bioavailability was only slightly decreased following administration of the microcapsules.