Abstract
Consumers apply deodorant daily to prevent malodour, as the smell of body odour can be embarrassing. However, some consumers experience dripping and wetting when applying the liquid deodorant, resulting in an unpleasant sensation. Due to that, modification to the liquid deodorant formulation and determination of optimum process parameters are necessary. The liquid deodorant formulation was modified by adding salt, followed by the measurement of surface tension through the pendant drop method and wettability through the contact angle method. There was an increase in the surface tension of the formulation with salt, attributed to the increase in polarity and cohesive forces. A higher contact angle was observed in the formulation with salt, indicating enhanced hydrophobicity, thereby offering improved skin adherence and comfort. Furthermore, to determine the optimum process parameters, conductivity measurements were demonstrated, showcasing the ionic nature of the deodorant formulations that contribute to electrical conductivity. Stirring rate optimisation indicated that a range of 400 to 500 rpm for 10 min achieved the desired dissolution efficiency while minimizing energy consumption. Meanwhile, safety and health assessments were conducted to ensure that the liquid deodorant does not pose any risks. Results indicate that potassium alum induces mild skin irritation, while sodium chloride and preservatives exhibit potential for serious eye irritation and internal harm if swallowed. Since eye exposure and ingestion are not the major exposure route, the liquid deodorant is considered relatively safe.
