Systematic Screening of Oil, Surfactant, and Cosurfactant for Ibuprofen Nanoemulsion

Ibuprofen, a widely used non-steroidal anti-inflammatory drug (NSAID), provides effective symptomatic relief; however, its oral administration is often associated with systemic side effects. Topical delivery via nanoemulsion systems offers a promising strategy to enhance local bioavailability while minimizing systemic exposure. This study aimed to systematically screen and identify optimal oil, surfactant, and cosurfactant components for ibuprofen nanoemulsion formulations. Ibuprofen solubility was assessed in various oils, followed by screening surfactants and cosurfactants based on emulsification efficiency, drug-loading capacity, and compatibility. Nanoemulsions were prepared using high-energy sonication methods and characterized for droplet size, polydispersity index (PDI), drug loading, and physical stability over 30 days. Capryol 90 exhibited the highest solubility for ibuprofen (103.01 ± 0.53 mg/mL), while Kolliphor RH 40 produced nanoemulsions with the smallest droplet size (109.7 ± 56.9 nm) and lowest PDI (0.214 ± 0.02). Transcutol P enabled the highest drug loading (280 mg/mL) and supported formulation stability. Ultrasonic bath sonication resulted in smaller, more uniform droplets than homogenizer sonication, and the optimized nanoemulsion maintained its droplet size and PDI throughout 30 days of storage. These results provide a preliminary basis for excipient selection in ibuprofen nanoemulsion development and suggest the potential for developing a stable topical delivery.