Radiation Sterilization of the Crude Drug "Glycyrrhiza".

Abstract

The microbial contamination levels of fifteen crude drugs “Glycyrrhiza”, which had been harvested in and imported from China and Russia, and their radiation sensitivities were investigated. Specified indicator microorganisms such as Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were not detected, and the number of bacteria and fungi adhering to those drugs were in the range 10 3-10 5cells/g and 102-105 spores/g, respectively. Those contamination levels were higher than values of the microbial limits of natural raw materials givenin The United States Pharmacopoeial Forum (1992). The average of D10 value as radiation sensitivity of bacteria and fungi to gamma rays were 2.2 and 0.98kGy, respectively. From these values, the survival doses (SD) required to attain the definitive microbial limits (bacteria, <20 CFU/g or ml; fungi, <10 CFU/g or ml) were calculated to be 7.5 kGy and 2.7 kGy. These SD values are sufficiently lower than the dose of 10 kGy allowed for food irradiation. On the other hand, the quality of Glycyrrhiza powder irradiated up to 30 kGy passed the “Crude Drugs Test”prescribed in The Japanese Pharmacopoeia Thirteenth Edition.