Evaluation of the Physical Properties and Anti-aging Microemulgel Sunscreen Nyamplung Oil (Calophyllum inophyllum L.)

Exposure to UV rays can cause photoaging, and a photoprotective compound can be used to prevent it, as well as being used as an active ingredient in sunscreen. The potential side effects and contamination of existing sunscreens on the market call for alternatives such as natural ingredients. Nyamplung oil (Calophyllum inophyllum L.) has the potential to be used as a sunscreen gel, with a 30.46 SPF value in its formulation. However, Nyamplung oil has the disadvantage of being hydrophobic. Therefore, this study aims to formulate it in the form of a microemulsion gel as a dual-action sunscreen with anti-aging activity. The optimization of the microemulsion formula were performed using Design Expert software, with observations on droplet size, polydispersity index (PDI), and zeta potential. The sunscreen was tested for its SPF value, percent () erythema transmission (Te), percent () pigmentation transmission (Tp), and percent () residual elastase enzyme activity (AE), to demonstrate its anti-aging activity, as well as being tested for its physical properties against the effects of storage, temperature, and photostability, and its safety in potential irritation on rabbits. The optimum microemulsion formula had a droplet size of 172.46 nm, a PDI of 0.196, and a zeta potential of-6.36 mV. The microemulgel sunscreen met the physical requirements of gel preparations, with an SPF value of 25.73, Te and Tp values for sunblock protection categories, and providing 62.96 anti-elastase activity at a concentration of 10. The sunscreen was stable during storage and with the influence of temperature. However, the sunscreen indicated a decrease in SPF value by 18.19 after a photostability test.