CHARACTERISTICS AND STABILITY OF IBUPROFEN MICROEMULSION PER INJECTION USING A COMBINATION OF MEDIUM-CHAIN TRIGLYCERIDE OIL, EXTRA VIRGIN OLIVE OIL, AND VIRGIN COCONUT OIL AS THE OIL PHASE

Abstract

Injectable ibuprofen has been formulated as nanoemulsion, prodrug microemulsion, and freeze-dried. However, its application is limited because of solubility, high dosing, and complex formulation. Microemulsion ibuprofen injection is an alternative dosage form that increases solubility and bioavailability. The study aimed to formulate an ibuprofen microemulsion injection that can fulfill the prerequisites for injection preparations with a simple method and simple reconstitution before use. All combinations of the oil and aqueous phases were formed using the self-emulsification technique. The optimum stability was estimated on particle size, polydispersity index (PDI), and zeta potential at 5°C, 25°C, and 40°C for 120 days. Based on the minimum amount of Tween 80, drug loading, and the highest transmittance value, the optimal microemulsion formula was obtained at a concentration of 2.8% (1:1 combination of olive oil and medium-chain triglyceride oil), 11.2% Tween 80, 2.8% propylene glycol, and 83.2% water for injection. The optimal formula has a droplet size of 16.7 ± 11.2 nm, a zeta potential of 0.8 mV, and a PDI of 0.196. The formula was stable at 45°C storage for up to 14 days, at 25°C, and at 5°C, steady at 120 days based on droplet size diameter of 21.27 ± 0.00 nm, zeta potential -1.3 ± 0.10 mV, and PDI 0.38 ± 0.02. The optimum formula by simple reconstitution without additional isotonization has fulfilled the requirements for injection preparation. It was concluded that the ibuprofen microemulsion with a combination of medium-chain triglyceride oil and olive oil could form a stable microemulsion and has the potential to be developed as a pharmaceutical preparation in the form of injectable ibuprofen.