Development and evaluation of essential oil-based lozenges using menthol and eucalyptus and In vitro evaluation of their antimicrobial activity in S. aureus and E. coli

The throat lozenegs are most commonly used first line of treatment for relief of various throat infections. The most common ingredient used in the lozenegs are various herbal extracts and essential oil having local action of throat area. in the present studies a essential oil based lozenges were prepared using eucalyptus oil and menthol as active ingredient. Antibacterial activity was evaluated for menthol and eucalyptus oil against human pathogens E.coli and S.aureus. both the sugar based and sugar free base was used to develop two types of lozenges formulation. Quality parameters were evaluated for lozenges formulations such as hardness, friability, dissolving time, and moisture content. Compatibility study was carried out using thin layer chromatography and gas chromatography analysis. The eucalyptus oil and menthol displayed moderate antibacterial activity against E.coli and S.aureus. The lozenges were found to be having satisfactory quality parameters. GC and TLC analysis was found to be a suitable method for identification of menthol and eucalyptus oil in the lozenges. TLC was found to be a simple, quick and simple technique for rapid identification of the essential oil and to confirm the batch-to-batch consistency. 1H-NMR and 13C-NMR was found to be useful tool for rapid identification of essential oils on basis of diagonostic peaks. Overall this study can be used for standard methods for quality control of the essential lozeneges formulation for the new formulation and product available in the market as well.