Preparation and characterization of tanshinone IIA OH-PDLLA-OR microspheres

Herein, the preparation of tanshinone IIA ester-terminated dl-polylactide (OH-PDLLA-OR) microspheres was studied, and their pharmaceutical properties were investigated. The OH-PDLLA-OR microspheres were prepared using the emulsion solvent evaporation method. The microspheres were characterized, including the determination of tanshinone IIA content using UV spectrophotometry, and the in vitro drug release characteristics of the microspheres were then investigated. After the optimal process, prepared microspheres were spherical and exhibited a regular, uniform distribution, no adhesion was observed, and the surfaces of the microspheres exhibited petal-like structures. The microspheres had an average particle size of 98.55 μm, the drug loading was (30.46 ± 0.03) %, the encapsulation rate was (73.48 ± 1.67) %, and the yield was (91.49 ± 2.11) %. The FT-IR and XRD results showed that the drug was successfully encapsulated in OH-PDLLA-OR after the preparation of the microspheres. The in vitro release showed that microspheres increased the release rate of the drug, which had a significant sustained effect. Thus, tanshinone IIA–OH–PDLLA-OR sustained-release microspheres have been successfully prepared.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide