Optimization of modifiers and process for changing superficial hydrophilicity of Indigo Naturalis / 中草药

ABSTRACT

Objective: To discuss the interaction between modifier and Indigo Naturalis by selecting the modifier that enhancing the superficial hydrophilicity of I. naturalis, then the best powder modification technique was selected to prepare the hydrophilic decoction pieces of I. naturalis, which can suit for decoction. Methods: In this paper, the contact angle was used to select the modifier, thermal stability was studied by different drying temperatures; Mechanism and thermal stability were studied according to the microstructure of alcohols, I. naturalis, and indirrubin preliminarily. Best technique was chosen by single factor experiment and uniform design. Results: Alcohols could enhance the superficial hydrophilicity of I. naturalis comparing to the normal one, the acts of -OH and -CH3 were different, and generally, the modifying effect of longer carbochain and polyhydroxy-alcohol was better. The best modifier was ethanol, the optimum modifying technique was 19% ethanol and grinding for 23 min. Conclusion: Above all, alcohols can enhance the superficial hydrophilicity of I. naturalis, the use of ethanol as modifier and the modifying process are reliable and suitable, and hydrophilic decoction pieces of I. naturalis can be prepared successfully.