STUDIES ON THE FORMULATION, PHYSICAL STABILITY, AND IN VITRO ANTIBACTERIAL ACTIVITY OF TEA TREE OIL (MELALEUCA ALTERNIFOLIA) NANOEMULSION GEL

Objective: This study aimed to formulate tea tree oil into a nanoemulsion gel dosage form and evaluate its physical stability and antibacterial activity.Methods: Nanoemulsion gels were formulated with various concentrations of tea tree oil, namely, 5%, 7%, and 9%, using Tween-80 as a surfactantand propylene glycol as a cosurfactant. The tea tree oil nanoemulsion gels showed a stable physical appearance over 8 weeks of storage at lowtemperature (4±2°C) and room temperature (25±2°C), cycling test, and centrifugation test.Results: The best formula was nanoemulsion gel formulation 1 (F1), which contained 5% tea tree oil, due to its good stability, smaller globule size,and greater viscosity. The results for antibacterial activity, determined by in vitro study, showed that the tea tree oil nanoemulsion gels exhibitedantibacterial activity against Propionibacterium acnes through the formation of an inhibition zone.Conclusion: Higher concentrations of tea tree oil in nanoemulsion gels (5%, 7%, and 9%) showed greater mean inhibition zones (28.33±0.88 mm,30.33±0.33 mm, and 31.67±0.33 mm, respectively)

Virtual Reality Adventures as an Effort to Improve the Quality of Welding Technology Learning During a Pandemic

Indonesia is one of the countries affected by changes in the education system and learning activities. Learning media aims at attracting students' interest in improving their cognitive and understanding of learning. The selection of media should be based on the following criteria: effective, useful, flexible, affordably accessible, and most importantly in line with learning objectives. Therefore, Virtual Reality-based learning media is the right technology for building online learning conditions to appear more real and real-time. This study aims to develop a VR-based learning media for welding technology courses. This study employed a Research and Development (R&D)  method with a 4D development model consisting of define, design, develop, and disseminate. Stages are carried out in stages with analytical and experimental formulations. The results showed that the total average indicators of the VR learning media material validation witch was 0.87 (valid) and the design validation assessment was 0.88 (valid). It can be concluded that the validation results of the learning media developed are declared valid and have been well tested, and are effective to be applied to welding technology learning