Drugs that occur naturally in a liquid form can be converted by microencapsulation to a pseudo-solid, free-flowing powder which is suitable for compounding with other active substances, tableting, filling into standard hard gelatin capsules, and other dosage forms that cannot be made with liquids. Microencapsulation, however, converts clofibrate to a dry, free-flowing powder, consisting of microscopic droplets of uniform size, individually coated with an ultrathin membrane made of a pharmacologically inert and completely harmless material. Many drugs have been successfully microencapsulated to obtain sustained release with all its inherent advantages; the following example is representative enough to account for the whole category. Many drugs that are taken orally irritate the gastrointestinal mucosa; some will literally make holes in the stomach, i.e., produce ulcerations. The drugs more commonly microencapsulated for taste abatement are vitamins and antibiotics; among the latter, an excellent example is the semisynthetic penicillin congener, flucloxacillin.