Formulation and evaluation of herbal gel containing essential oils of piper betle against skin infecting pathogens

Abstract

The aim of the present study was to investigate the antimicrobial potency of essential oil of piper betle against different skin infecting pathogens and to formulate and evaluate suitable dermatological preparation containing betle oil as the active ingredient. The evaluation of antimicrobial potency of betle oil was studied prior to gel formulation to compare the changes in activity after incorporation in polymer gel. The assay was done using agar well disc diffusion method for zone of inhibition and broth dilution method for MIC (Minimum Inhibitory Concentration). Zone of inhibition was found to be maximum that was 26mm at 15µl for S. aureus followed by 19mm at 25 µl for P.aeruginosa, 20 mm at 20 µl for S.epidermidis, 22mm at 18 µl for E. coli, 21.6mm at 18 µl for M.luteus. Among the fungus C.albicans showed maximum sensitivity to the oil that was 24mm at 20 µl and 20mm at 20 µl for A. niger. Gels were formulated by using different polymers like hydroxy propyl methyl cellulos e (HPMC), Carbopol 934, sodium carboxy methyl cellulose (sodium CMC), sodium alginate and evaluated for various physicochemical parameters like pH, viscosity, consistency, homogeneity, spreadability, skin irritation test and stability study. MIC for all the tested pathogens was below 60 µg/ml. Dimethyl sulfoxide (DMSO) as the co‐solvent for the essential oil and Carbopol 934 (1%), HPMC (5%) as gelling agent showed the best results in final formulations. Zone of inhibition of oil was not much affected by incorporation in gel which was confirmed from the antimicrobial results of final formulations. The gel showed promising antibacterial and antifungal activity against other strains used for the study. The gel was stable at room temperature.