This study explored the preparation process of the placebo of Jiawei Ermiao Granules and evaluated the placebo effect, aiming to provide qualified placebo samples for clinical trials of Jiawei Ermiao Granules and a reference for the preparation and quality evaluation of placebos of traditional Chinese medicine granules. On the basis of the comprehensive analysis results of Jiawei Ermiao Granules, the orthogonal experiment was conducted to optimize the flavoring agents and colorants. After manual evaluation, the placebo formula was determined as dextrin 10 g, Codonopsis Radix extract 5.0 g, bitter melon extract 1.6 g, Mume Fructus extract 0.3 g, stevioside 0.1 g, sucrose octaacetate 0.004 g, indigo 0.004 g, lemon yellow 0.003 1 g, sunset yellow 0.001 8 g, bitter tea powder 0.001 8 g, caramel 0.001 3 g. Pilot trials were conducted on the placebo formula. The simulation effect of placebo was evaluated independently and comparatively, and the objectively evaluated by electronic nose and electronic tongue. The results showed that the independent manual evaluation of the placebo formula had higher error rate, and the placebo and Jiawei Ermiao Granules showed the similarity of 99.61% in the comparative manual evaluation. The smell similarity between the placebo and Jiawei Ermiao Granules was 99.19%, and the electronic tongue test showed little difference in the taste. In conclusion, the placebo prepared in this study shows a high similarity to Jiawei Ermiao Granules, which is not easy to break the blindness when being applied to clinical trials. This study provides a reference for the preparation and quality evaluation and promotes the large-scale production of placebos of traditional Chinese medicine granules, playing a role in improving the persuasiveness and acceptance of the efficacy of traditional Chinese medicines.
Keywords: Jiawei Ermiao Granules; manual evaluation; objective evaluation; placebo; preparation process; similarity.