Preparation of personalized traditional Chinese medicine condensed water pill without excipients based on correlation between concentrate viscosity and molding quality

To explore the correlation between concentrate viscosity and molding quality of personalized traditional Chinese medicine(TCM) condensed water pill, this study established a concentrate viscosity characterization method with rotational rheometry. Seven model prescriptions were respectively concentrated to different degrees and the viscosity of each concentrate was determined. The pre-sence of 'viscosity jump' in the middle stage of 'flag hanging' of all the model prescriptions implied that there might be an ideal viscosity range in the preparation of condensed water pill. The further study of 22 model prescriptions demonstrated that the optimum viscosity range of concentrate was 5-15 Pa·s(25 ℃) for approximately 82% of the prescriptions. About 18% of the prescriptions had a wide range, which might be caused by the high proportions of mineral and crustacean drugs in the crushing part and sugar and fibrous drugs in the decocting part. This study clarified the optimum viscosity range for concentrates of personalized TCM condensed water pills and achieved a preparation technology without any excipient, laying a foundation for the on-line control of the preparation.