[Comparative Study on Boiling Powder and Traditional Herbal Pieces of Rhubarb].

Objective: To optimize the particle size of rhubarb boiling powder, to determine decoction process of rhubarb boiling powder through the comparative study with traditional herbal pieces.

Methods: Three kinds of particle size of rhubarb boiling powder were prepared. The content of aloe emodin,rhein, emodin, chrysophanol and emodin monomethyl ether were detected by HPLC,and to determine particle size of rhubarb boiling powder according to the content of total chemical ingredients and dry extract rate in water decoction. The effect of the amount of water and decocting time on decoction of boiling powder and traditional herbal pieces of rhubarb were systematically investigated by using single factor test.

Results: Firstly, the content of 2 mm to 0. 18 mm particles in rhubarb boiling powder can not be less than 80%. Total anthraquinone content and dry extract rate had no significant difference in the decoction of boiling powder in the amount of water between 14 ~ 20 times; decocting time had no significant effect on total anthraquinone and dry extract rate; the content of combined anthraquinone decreased significantly, while the decocting time was more than 20 min. The decocting time had great influence on the herbal pieces, with ten times of water,and decocting 5 ~ 50 min each time, the compound content and dry extract rate of boiling powder were 3. 23 ~ 9. 48 times and 1. 61 ~ 3. 44 times than that of traditional herbal pieces, and with the extension of the decocting time, the gap was narrowing.

Conclusion: Preparation process of rhubarb boiling powder is simple and suitable for industrial production, boiling powder can save more than half of the amount of traditional herbal pieces with ten times of water, decocting one times, decoction time of 10 ~ 15 min.