Formulation and characterization of Amphotericin B encapsulated in poly (DL, lactide-co-caprolactone) microspheres

Abstract

Amphotericin B (AmB) is the gold standard drug used to treat severe systemic fungal diseases. But, its use is limited due to its high toxicity. This drug should be entrapped in biodegradable polymer microspheres to decrease its toxic effects. Many attempts were done to encapsulate AmB drug particles in different polymers such as poly lactide and poly caprolactone, but the encapsulation efficiency and the drug release profile were not convenient. Thus, to improve these parameters, we encapsulated this drug in the co-polymer of the above used polymers: poly (DL,lactide-co-caprolactone) (PLC). The AmB- PLC microspheres were formed by o/w solvent evaporation technique. The characterization of these microspheres were studied according to: drug entrapment, drug loading, particle size, morphology study, FT-IR drug-polymer interaction, stability and in vitro drug release. These studies showed a high percent of entrapment efficiency estimated by 81% .The microspheres formed had a spherical shape with porous surface and homogeneous size distribution having an average size of 80-90 µm. FT-IR studies of AmB-PLC microspheres revealed the absence of any drug-polymer interaction. Stability of microspheres against different temperatures showed no major degradation of microspheres during 3 months of storage. In vitro drug release of the prepared formulations showed a sustained release profile, with a burst effect for the microspheres with highest drug loading (0.12- 0.16 %).