Optimization of a novel bioerodible device based on auto-catalyzed poly(ortho esters) for controlled delivery of tetracycline to periodontal pocket

Local delivery of antimicrobial agents in inflamed periodontal pocket has b een shown to be effective in reducing periodontopathic microorganisms. This research focuses on developing and characterizing bioerodible Formulations based on auto-catalyzed poly(ortho esters) (POE(x)LA(y)) for modulated rel ease of tetracycline over 2 weeks. POE(x)LA(y) are a new versatile family o f POE-containing lactoyl lactyl dimers in the polymer backbone. By modifyin g the proportion of lactic acid in the polymer, viscous or solid materials having different degradation rate can be produced. The formulations can be either injected or placed as a solid device directly into the periodontal p ocket. Tetracycline-free base incorporated into these materials was release d within 10-14 days depending on polymer structure. Increase in lactic acid content in the polymer tended to increase the drug release rate and to red uce the initial lag time. Tetracycline release from such bioerodible delive ry system occurs predominantly by surface erosion of the polymeric matrix, leading to kinetics which can be zero order. This periodontal drug delivery system is designed to be used as an adjunct in the treatment of periodonta l diseases. Clinical studies are currently in progress. (C) 2001 Elsevier S cience Ltd. All rights reserved.