Author(s):
Harshal Patil, Jyotsna Waghmare
Email(s):
harshalvpatil1612@gmail.com , jyotsna.waghmare@gmail.com
DOI:
10.52711/2231-5659.2026.00034 
Address:
Harshal Patil, Jyotsna Waghmare
Department of Oils, Oleochemicals and Surfactant Technology Institute of Chemical Technology (ICT), Nathalal Parikh Marg, Matunga (E), Mumbai - 400019, Maharashtra, India.
*Corresponding Author
Published In:
Volume - 16,
Issue - 3,
Year - 2026
ABSTRACT:
The present study discusses the systematic development and physicochemical characterization of a new microemulsion-based anti-aging cosmetic serum containing watermelon seed oil (WSO) and walnut oil (WO) as bioactive oil phases. Pseudo-ternary phase diagrams were constructed by aqueous titration methodology to identify optimal microemulsion regions with vegetable oil ethoxylate surfactants like Hydrogenated castor oil ethoxylated and Grapeseed oil ethoxylated. Four stable oil-in-water (O/W) microemulsion formulations (S1-S4) were prepared with variable oil blend ratios (WSO: WO of 70:30 and 30:70) and variable HLB values (11.4 and 12.4). Comprehensive physicochemical characterization of these formulations revealed particle sizes within the range of 123.2 to 268nm, polydispersity indices of 0.306-0.388, pH within the range of 6.75-6.90, viscosity in the range of 120-153cPs, and conductivity within 266.6-375.3mS/m. All formulations showed excellent stability after centrifugation, freeze-thaw cycling, and accelerated storage conditions of 45°C for 30 days, with no phase separation, a pH variation of less than 0.5 units, and acceptable viscosity changes. Skin irritation testing on human volunteers confirmed dermatological safety, with the formulation classified as non-irritant to practically non-irritant. Sensory evaluation yielded high acceptability scores of 4.3-5.0 on a 5-point hedonic scale across all parameters of appearance, texture, absorbability, and after-feel. Formulation-4 (WSO:WO, 30:70; HLB, 12.4) showed superior performance, having the least droplet size (123.2nm), optimal viscosity of 153cPs, and maximum sensory acceptance. Thus, the developed microemulsion system can successfully merge the complementary fatty acid profiles along with antioxidant properties of both botanical oils into a thermodynamically stable, elegant delivery platform suitable for commercial anti-aging cosmetic applications.
Cite this article:
Harshal Patil, Jyotsna Waghmare. Formulation and Physicochemical Evaluation of Watermelon Seed Oil-Walnut Oil Microemulsion: A Novel Approach for Anti-Aging Cosmetic Delivery. Asian Journal of Research in Pharmaceutical Sciences. 2026; 16(3):225-3. doi: 10.52711/2231-5659.2026.00034
Cite(Electronic):
Harshal Patil, Jyotsna Waghmare. Formulation and Physicochemical Evaluation of Watermelon Seed Oil-Walnut Oil Microemulsion: A Novel Approach for Anti-Aging Cosmetic Delivery. Asian Journal of Research in Pharmaceutical Sciences. 2026; 16(3):225-3. doi: 10.52711/2231-5659.2026.00034 Available on: https://www.ajpsonline.com/AbstractView.aspx?PID=2026-16-3-3
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