An injectable formulation of sustained-release microsphere gel containing triamcinolone acetonide microreservoir and its preparation method

Abstract

This invention provides an injectable formulation of sustained-release microsphere gel containing triamcinolone acetonide microreservoirs and its preparation method, belonging to the field of pharmaceutical formulation technology. A synergistic system of "stable microreservoir encapsulation – controlled diffusion / degradation of the microsphere framework – secondary retardation by the gel network" is constructed: cyclodextrin is capped with diacyl chloride and crosslinked with diglycidyl ether to form a stable microreservoir, thus restricting triamcinolone acetonide encapsulation and reducing crystallization / leakage; the microreservoir-containing dispersed phase is introduced into the biodegradable polymer spheres, enabling drug release to form a two-stage tandem controlled release of "microreservoir dissociation / migration – matrix diffusion / erosion," inhibiting burst release and improving release smoothness and predictability; the gradient PEG framework balances outer layer wetting and dispersion with inner layer long-lasting sustained release, and promotes the outward diffusion of degradation products; the polysaccharide crosslinked gel provides load-bearing and rheological support, and, in conjunction with a compatibility enhancer, stabilizes and disperses the microspheres, reduces sedimentation and aggregation, while simultaneously creating secondary retardation of outward diffusion and prolonging local retention.

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