Design and Development of Long-Acting Depot Injection of Triamcinolone Acetonide

Abstract

The study focuses on developing a biodegradable in situ gel-forming depot injection to overcome the limitations of conventional triamcinolone acetonide therapy by enhancing drug retention and prolonging its anti-inflammatory action. Using SABER™ Technology, PLGA was dissolved in DMSO, blended with SAIB, and loaded with triamcinolone acetonide to obtain a clear, uniform sustained-release formulation. A D-optimal mixture design with three independent variables was employed for optimization, and the final system was evaluated for syringeability and in vitro release over 24–600hours. The formulations showed a steady, sustained drug release, increasing from 4.5–9.5% at 24hours to 74.3–84.5% at 600hours, with release kinetics best described by the Higuchi model (r² = 0.9784), confirming diffusion-controlled drug liberation. Overall, a long-acting in situ forming depot was successfully developed for intra-articular delivery, with the PLGA–SAIB–DMSO combination supporting extended release, suitable physicochemical properties, and ease of injection. The optimized system shows strong potential to provide longer-lasting relief, reduce dosing frequency, and improve patient compliance compared with standard corticosteroid injections.