Abstract:
This study aimed to investigate the antibacterial activity of emulsified Manuka beeswax. Many bee products are incorporated into various applications due to its antibacterial activities. But the antibacterial activity of beeswax by itself has not shown positive results. In this study, using the moisture content of commercial hand creams as a basis, the formulations of O/W emulsions containing beeswax and olive oil as the oil phase were developed to produce a hand cream. Emulsification was carried out with ultrasonication. From the rheological instrumental results, it was found that all samples portrayed pseudoplastic and shear thinning behaviours as the apparent viscosity decreased with a change in the shear rate. The emulsion sample 2C2 containing 60% water and 40% oil phase (of the 40%; 25% beeswax and 75% olive oil) and sample 2C4 containing 65% water and 35% oil phase (of the 35%; 25% BW and 75% OO) sonicated for one minute displayed favourable textural characteristics. Antibacterial testing on several emulsion samples have concluded to show that raw or emulsified beeswax do not demonstrate antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli. Due to the lack of reduction of growth of bacterial species observed in agar diffusion assay, a different method was devised. An aliquot of bacterial suspension was placed in contact with fresh broth and the emulsion sample mixture. No significant reduction was observed for samples containing beeswax, olive oil and water only. Therefore a new formulation was developed by including Manuka honey because Manuka honey has been proven to exert many therapeutic effects and its antibacterial activity has been proven by many studies. The implemented formulation displays significant reductions in growth (p < 0.05) of the species mentioned above. Although the new formulation (2C2-H) possesses antibacterial activity, it did not score highly on the attributes ‘texture’ and ‘appearance’ in the sensory evaluation. 2C2 scored highest out of the prepared samples for the appearance and textural aspects but did not score highly for the smell. 2C2-H scored very high for the smell. With slight modifications, production of a beneficial hand cream possessing antibacterial properties and good textural aspects can be expected.