The invention relates to a preparation method of extract of granules containing radix scrophulariae,
radix ophiopogonis, radix glycyrrhizae and radix platycodonis. The preparation method is characterized by comprising the following
processing steps: first, soaking radix scrophulariae for 2-3 h, mixing the soaked radix scrophulariae with
radix ophiopogonis, radix glycyrrhizae and radix platycodonis, adding 9-10 folds of water, carrying out soaking for 25-30 min, carrying out heating till the boiling state is achieved, carrying out first-time extracting, carrying out filtering, adding 9-10 foldsof water into the obtained filter residue, carrying out heating till the boiling state is achieved, carrying out second-time extracting, carrying out second-time filtering, adding 7-8 folds of waterinto the obtained filter residue, carrying out heating till the boiling state is achieved, carrying out third-time extracting, mixing the filtrates obtained after the three times of filtering, carrying out concentrating, carrying out standing, carrying out centrifugalizing, carrying out re-concentrating, and collecting the extract. According to the preparation method provided by the invention, themethod of shortening the soaking time is adopted for treating the traditional Chinese medicinal materials of the granules containing radix scrophulariae,
radix ophiopogonis, radix glycyrrhizae and radix platycodonis, so that the content of
harpagoside in the extract of the granules containing radix scrophulariae, radix ophiopogonis, radix glycyrrhizae and radix platycodonis is improved, and meanwhile, the time consumed by the process is shortened correspondingly.