FORMULATION AND EVALUATION OF PARENTERAL IN-SITU FORMING BIODEGRADABLE IMPLANT FOR CONTROLLED RELEASE OF LEVOTHYROXINE SODIUM

Abstract

Objective: The objective of present research work is formulation and evaluation of parenteral in-situ forming biodegradable implant for controlled release of levothyroxine sodium. Material and Method: The present study used N-Methyl pyrrolidone (NMP) and triacetin as solvents and PLGA as a biodegradable polymer to manufacture two biodegradable polymeric drug delivery systems, in-situ forming implant (ISFI) and in-situ micro particles (ISM). Other evaluation tests, such as sterility, percent drug entrapment capacity, and so on, were also carried out. ISFI and ISM were tested for up to one month at three different temperatures (4ºC, 25ºC, and 40ºC). Result and Discussions: The drug release from both systems was compared. The polymer content, type of solvent (hydrophilic or hydrophobic), and implant morphology all contributed to increased burst release in the ISFI formulation. Burst release was decreased using a combination of hydrophilic and hydrophobic solvents (NMP and Triacetin). When compared to other formulations, ISM had the lowest burst release. Both the ISFI and ISM formulations might deliver medications for up to 30 days. Long-acting Levothyroxine sodium formulations (ISFI & ISM) may be a superior option for hypothyroidism treatment. Keyword: In-situ Implant, Biodegradable polymers, PLGA, Long term release, Solvent exchange technique, ISFI, ISM.