Textual Research on Principle of Dose Conversion in Ancient Famous Classical Formulas / 中国实验方剂学杂志

ABSTRACT

Due to the difference between the system of weights and measures， and the dosage of clinical prescriptions of traditional Chinese medicine in various historical periods， the dosage and conversion standard of prescriptions in past dynasties are different. Therefore， when discounting the dosage of famous classical formulas， the principles of inheriting the essence， making the past serve the present， linking the past and the present， and forming a consensus should be followed， firstly， the dosage of the prescription was converted according to the weights and measures system of the past dynasties. If the converted dosage significantly exceeds the provisions of the 2020 edition of Chinese Pharmacopoeia， then on the premise of ensuring that the proportion of the original prescription drug dosage remains unchanged， the conversion shall be based on expert consensus and drug safety evaluation. For drugs measured in non-standard units， a conversion range is provided based on comprehensive literature analysis and physical measurements. For the conversion of service volume， the original text was used as the basis for the conversion with reference to the measurement standards of different eras. If the original dosage is not clear， the converted dosage will be determined based on the historical evolution of the formula， referring to relevant ancient books， and combining modern applications. Eventually， the converting standard for famous classical formulas was determined as follows：during the Han and Tang dynasties， one Liang（两） was equivalent to 13.8 g and one Sheng（升） was equivalent to 200 mL， in the Tang dynasty， one Fen（分） was equivalent to 3.45 g， during the Song， Jin and Yuan dynasties， one Qian（钱） was equivalent to 4.13 g and one Zhan（盏） was equivalent to 300 mL， during the Ming and Qing dynasties， one Qian（钱） was equivalent to 3.73 g， and one Bei（杯） and one Zhong（盅） were equivalent to 200 mL. For drugs recorded in non-standard units of measurement， it is necessary to conduct actual measurements to determine their conversion standards based on comprehensive analysis to determine their origin. If necessary， different records of the dosage of drugs with the same or similar efficacy and indications in medical books of similar ages can be used to assist in determining the conversion standards. The analysis of the principle of dosage conversion for Chinese medicine is helpful for the clinical application and development of famous classical formulas.