Abstract:

Triamcinolone acetonide has the advantages of strong medical efficacy and long duration, however, its oil solubility limits its application. Poly（lactic-co-glycolic acid） （PLGA） has excellent biocompatibility and biodegradability, which can be made into microspheres loaded with triamcinolone acetonide. In this work, the PLGA was prepared using trifluoromethanesulfonic acid as catalyst and glucose as initiator. The molecular structure, molecular weight and molecular weight distribution of PLGA were characterized by NMR and gel chromatography. The results showed that the mass ratio of lactic acid to glycolic acid segments in PLGA was 50:50, and the molecules were terminated with carboxyl groups, and the molecular weight was between 36 000 and 41 000, exhibiting narrow molecular weight distribution （molecular weight distribution index was ca. 1.60）. The microspheres were made by electrostatic spraying method, whose particle size was less than 20 μm （the content of microspheres of diameter being smaller than 20 μm was more than 92%）. The drug loading efficiency for triamcinolone acetonide was more than 44%, and the period of release was up to 120 h. In the initial stage of drug release, the relationship between drug release rate and time was linear. This work could provide basic data for the preparation of PLGA microspheres for drug-loading and expand the application of triamcinolone acetonide in the treatment of allergic dermatitis, neurodermatitis and chronic eczema. Moreover, this work could provide reference for the development of functional skin care products.

Key words: triamcinolone acetonide, poly（lactic-co-glycolic acid）, microsphere, drug loading