Development, Characterisation of Menthol based non-alcoholic propolis extracts and its effect on chemical composition of propolis analysed using RP-HPLC

Propolis had been used as anti-inflammatory, immunomodulatory, antibacterial and antiviral agent since ages and proven to cure wounds, sore throats and colds. The challenge throughout these years has been its poor solubility, several methods have been applied to improve its solubility in water, oil and waxy mixtures, as ethanolic extracts have its limitation to be applied in the pharmaceutical and cosmetic industry. Active ingredients of propolis are readily soluble in ethanol, though they are scarcely soluble in the oil, water or waxy extracts. To address this issue menthol in combination with lactic acid and salicylic acid based propolis extract was developed and its chemical composition was analysed and compared with the alcoholic extract as control. Non-alcoholic extract showed 2-fold less solubility of propolis compared to control. HPLC of menthol based non -alcoholic extracts indicated the presence of active ingredients such as Ferulic acid, Cinnamic acid, Naringenin, Pinocembrin, Chyrsin and Galangin similar to alcoholic extract except Quercetin. These solvents find their application in the cosmetic and pharmaceutical industry as topical formulations, as terpenes enhance the permeability of the active ingredients.