Encapsulation of metronidazole in polycaprolactone microspheres

Non-aqueous oil-in-oil solvent evaporation technique is used for the preparation of polycaprolactone microspheres loaded with the antibiotic metronidazole by introducing different masses for the drug. The prepared microspheres are characterized by calculating drug encapsulation and drug loading percentages, measuring the corresponding particle size, performing FT-IR polymer-drug compatibility study and in vitro drug release. Moderate drug encapsulation values with a maximum of 34% are observed due to the low molecular weight of the drug. Microspheres had a particle size ranging between 130 and 280 µm with a spherical profile and porous structure. FT-IR study showed no interactions between the drug and the polymer. Drug release studies showed fast release rates for all the formulations with the slowest release for the highest drug loading. Keywords: polycaprolactone, metronidazole, targeted drug delivery, solvent evaporation.