Atividade antimicrobiana do óleo essencial de Melaleuca e sua incorporação em um creme mucocutâneo

Essential oils with antimicrobial activity have aroused researchers' interest for being a therapeutic alternative when properly studied. To identify the minimal inhibitory concentration (MIC50) of melaleuca oil against three microorganisms Escherichia coli, Staphylococcus aureus and Candida albicans,when incorporated in O/W cream to evaluate its preliminary stability for 10 days, using statistical methods to complete this study. The assay was performed by serial micro-dilution in a sterile ELISA plate. The microorganisms were suspended in saline solution by using the McFarland scale (106 for fungus and 103 for bacteria). CIM50 corresponded to 50% reduction of growth halo in the lowest concentration of melaleuca O/W cream. The minimum inhibitory concentrations for the evaluated microorganisms were 9.0 mg/mL for Staphylococcus aureus, 4.5 mg/mL for Escherichia coli and 4.5 mg/mL for Candida albicans. The developed cream did not show significant changes in density, pH or in its physical characteristics. The obtained results are promising for the development of pharmaceutical semi solid dosage forms with the incorporation of melaleuca oil as a possible new therapeutic alternative against the microorganisms studied.