Antimicrobial activity evaluation for gentamicin loaded PLA microspheres

Abstract

Abstract Poly(lactic) acid (PLA) is well known as a drug carrier in drug delivery system. Double emulsion and solvent evaporation technique was used to encapsulate gentamicin within PLA microspheres. The ability of PLA microspheres to encapsulate gentamicin was investigated at three different wt%; 0.125%, 0.25% and 0.375%. The highest encapsulation efficiency (42.3%) and drug loading (26.5x10-3%) was observed at 0.375 wt% gentamicin loaded. For antimicrobial assay, the diameter for zone of inhibition was measured and compared for each wt% of gentamicin used. This evaluation was done to determine the effectiveness of gentamicin delivery from the PLA microspheres to inhibit the growth of Staphylococcus aureus. The higher wt% of gentamicin loaded into the PLA microspheres, the larger the diameter for zone of inhibition was obtained with the highest diameter at 0.375 wt% (2.3 cm). The study showed that the PLA is having potential to serve as a slow and sustained release drug delivery vehicle since the inhibition zone only can be measured after day 3 of incubation.