Introduction: Ha-Rak is a well-known Thai remedy orally taken for fever. The powder has been used for topical application against dermatitis. In this study, turmeric powder of equal amount wasadded to Ha-Rak powder yielding Prasakhaminchan of Ha-Rak remedy. Previous studies of both Ha-Rak remedy and turmeric had established safety profiles on rat and human skin. However,no study has been done on the safety profile of Prasakhaminchan of Ha-Rak remedy on human skin. Therefore, this study was to investigate the skin irritation and allergic testing of Thai herbalextracts (Ha-Rak with turmeric) in healthy volunteers. Method: Various concentrations (0.25-10% w/w) of Ha-Rak extract, turmeric extract, Prasakhaminchan of Ha-Rak extract in white petrolatum and in cream base were prepared. A patch test wasperformed on 30 healthy volunteers for 48 hours. The skin reactions were evaluated after 48 hours and also 72 hours. Results: Only one person had slight (1+) allergic reaction to turmeric extract, Prasakhaminchan of Ha-Rak extract in white petrolatum and turmeric extract in cream base. There was no allergicreaction to Ha-Rak extract and Prasakhaminchan of Ha-Rak extract in cream base. There was no irritation from Ha-Rak, turmeric and Prasakhaminchan of Ha-Rak extracts in white petrolatumand in cream base. Conclusion: Ha-Rak, turmeric and Prasakhaminchan of Ha-Rak extracts at 0.25-10 % w/w in cream base and in white petrolatum did not cause skin irritation, therefore they are safe to be used as topical medication for skin. However, people who has hypersensitivity to turmeric should avoid these medicaments.
Srichaipor et al. (Wed,) studied this question.