Formulation and Physical Stability Study of Oyster Mushroom (Pleurotus ostreatus) Water Extract Gel

Oyster mushrooms contain several metabolites that have the potential to be developed, including the β-glucan compound and polysaccharide contents of oyster mushrooms, which have pharmacological activity. Water extract from oyster mushrooms has anti-inflammatory activity against skin suffering from atopic dermatitis. This study aims to formulate oyster mushroom extract into gel preparation for potential treatment of atopic dermatitis. To achieve this objective, some formulation designs were defined. There are four formulas with oyster mushroom extract variation. The independent variable is extract concentration, while the responses included pH, viscosity, spreadability, and adhesion, including stability studies in specific conditions. The best formula was performed by Formula 1 with 0.2% of the extract with a pH of 6.0, which is within the range of suitable pH to maintain the skin’s natural barrier function, a viscosity of 6025 cP, a spreadability of 5.1 cm, and an adhesion of 2.7 seconds. The optimum formula proved to be physically stable after three months of stability testing and showed no irritation after the irritation test on animals