Background and Objective: The pH has been shown to affect curcumin stability. However, no studies regarding the effects of pH of dispersion system during curcumin niosomes construction have been reported. This study investigates the influence of pH value during the incorporation of curcumin into niosomes on the properties of vesicles. Materials and Methods: Niosomes were prepared using Span 60/Tween 60 at 1:1 mole ratio with the addition of dicetylphosphate and cholesterol via thin film hydration method. Curcumin incorporation into niosomes was conducted at pH 3, 7 and 9. The size of niosomes was reduced using extrusion. Results: Spherical niosomes was obtained at pH 3 and pH 7, while preparation at pH 9 produced irregular shaped niosomes. The entrapment efficiency of niosomes prepared at all pH was more than 60%, in which the highest was for niosomes prepared at pH 3 (75.23±2.85%). The initial size of niosomes (>376 nm) was reduced to <160 nm using extrusion. Although extruded niosomes have zeta potentials less negative than -30 mV, the niosomes showed minimal increase in size due to aggregation after 28 days of storage at all conditions. Conclusion: The pH during hydration process does not significantly affect the size of the vesicles before storage, but influences its stability with respect to their rigidity structure during storage. The high entrapment efficiency of niosomes prepared at pH 3 suggested that it is more favorable to incorporate curcumin into vesicles in acidic medium.
Wee Jie Gong, Masrina Mohd Nadzir, Siti Farhana Hisham and Saravanan Reddy Kalidas, 2020. Size, Entrapment Efficiency and Stability of Curcumin Niosomes Prepared at Different pH Conditions. Asian Journal of Scientific Research, 13: 23-28.