Changes in the Characteristics of Water-in-Oil-based High Internal Phase Emulsion Containing Moringa Leaves Extract at Various Storage Conditions

Purpose: To explore changes in the characteristics of water-in-oil-based high internal phase emulsion containing Moringa oleifera (Moringa HIPE) extract at various storage conditions and time intervals. Methods: Moringa leaves extract (3 %) was entrapped into HIPE. Color, liquefaction, conductivity, pH, and centrifugation were assessed by keeping the samples of Moringa HIPE at 8, 25, 40 and 40 °C, and 75 % RH (relative humidity) over time up to 54 days. Rheological measurements were made on freshly prepared emulsion and after one and two months. Data were analysed using Brookfield Software Rheocalc version (2.6) with IPC Paste and Power Law (PL) math models. Results: There was no change in color, electrical conductivity, liquefaction and phase separation (after centrifugation) in any sample of Moringa HIPE at the various storage conditions and periods. The pH of freshly prepared Moringa HIPE was 5.5 which gradually decreased with slight variation in the storage conditions. The viscosity of freshly prepared emulsion was 3256.65 cP and this decreased with increase in shear stress. Flow index and shear sensitivity factor of freshly prepared emulsion were 0.36 and 0.65, respectively. The rheograms of Moringa HIPEs indicate non-Newtonian behaviour and pseudo-plastic tendency. Power Law and IPC paste provided the data of confidences of fit. Conclusion: Moringa HIPE showed stability and can be guided exclusively to protect skin against ultraviolet radiation-mediated oxidative damage.