Controlled-release therapeutic systems: technology applicable to the treatment of oral disease.

Abstract

Controlled-release therapeutic systems are designed to deliver a pre-determined amount of drug to a specific anatomical site for an extended period of time. A single controlled-release delivery system no larger than an ordinary tablet or capsule and placed at the desired site of drug action can produce long-term therapeutic effects that previously could only be achieved through multiple administration of conventional dosage forms. Transient spikes in drug concentration seen with multiple dose regimens are eliminated, decreasing the chance of adverse reactions. Because they are effective for an extended period of time, controlled-release therapeutic systems minimize the involvement of the patient in drug administration , a factor which can increase both patient compliance with a prescribed regimen and patient satisfaction with the treatment schedule compared with conventional therapy. Controlled-release technology can be utilized to deliver therapeutic agents ranging in size from small ions to macromolecules. Clinically-proven controlled-release drug delivery systems are currently available with durations of action ranging from several days (e.g., for the prevention and treatment of angina pectoris and motion-induced nausea and the treatment of glaucoma) to one year (e.g. for contraception). A therapeutic system for contraception with a five-year effective lifetime is in clinical trial. Intra-oral controlled-release therapeutic systems are being investigated for the delivery of fluoride and antibiotics. A system for fluoride has reduced experimental dental caries in rats by over 50% and has significantly elevated salivary fluoride concentrations during a six-month trial in adolescents. Tetracycline-containing polymeric fibers can provide site-specific delivery of the antibiotic to periodontal pockets for 10 days or more. An intra-oral controlled-release pellet for tetracycline with a duration of action of one to two weeks is being developed, and additional possibilities exist for the intra-oral use of this versatile technology.