Ceramic drug delivery systems have been used to deliver amino acids, hormones, nucleosides, phenolics, polypeptides, proteins, steroids, and trichloroethane at constant rates for desired durations in both in vitro and in vivo environments. Biologicals, chemicals, drugs, and hormones have been delivered by both matrix and reservoir types of ceramic drug delivery systems for various purposes in rats, rabbits, sheep, and monkeys. Ceramic drug delivery systems have been used to: study the toxicity of trichloroethane, administer azidothymidine (AZT) and gossypol without side effects, prevent experimentally induced trypanosomiasis, sustain life and maintain normal metabolism in adrenalectomized animals, alleviate pain, administer antibiotics, deliver insulin and regulate blood sugar, inhibit or enhance spermatogenesis, administer osteogenic agents, and deliver anticoagulants.