The prescriptions of traditional Chinese medicine (TCM) can be defined as a preparation which, on the basis of the differentiation of syndromes and the establishment of therapeutic methods, organically combines various drugs for the prevention and treatment of diseases in accordance with a certain principle of formulating a prescription. Pharmacology of traditional Chinese medicinal formulae is a science that studies and interprets the theories of prescriptions and their administrations.
The formation and development of prescriptions have undergone a very long historical period. As far back as in the early period of slavery society, man began to use a single drug to prevent and treat diseases. In the Shang Dynasty, because of the increased variety of drugs and the enrichment of knowledge about diseases, more drugs were selected according to the different symptoms of illness to formulate compound prescriptions for clinical uses. People began to use compound drugs instead of a single one, thus greatly improving the curative effect. This is the embryonic form of prescriptions of TCM. A prescription book entitled "The Prescriptions for Fifty-two Kinds of Disease" was unearthed in 1979 from the No. 3 Han Tomb at Ma Wang Dui, Changsha, Hunan Province. It is the earliest extant medical formulary in China.
With the development of traditional Chinese medicine, the prescription itself has also become perfected and enriched. Around the Warring States period and in the Qin and Han Dynasties, a classical writing of TCM entitled "The Yellow Emperor's Canon of Internal Medicine" came out. This is the earliest book dealing with the basic theories of the science of TCM formulae, such as the principle of formulating a prescription, incompatibility of drugs in a prescription, some dosage forms and their usages. The book consisting of 13 prescriptions has laid a solid foundation for the formation and the development of the science of TCM formulae. Zhang Zhongjing, an outstanding physician in the Eastern Han Dynasty, after diligently seeking the ancient experience and book knowledge and extensively collecting numerous prescriptions, compiled "Treatise on Febrile and Miscellaneous Diseases" which contains 269 prescriptions. This book gives interpretations in detail to the modification of the prescriptions and their administrations. The dosage forms are also quite excellent. Therefore, the book has been honored as the "forerunner of prescription books" by all the later physicians. In the prosperous period of the Tang Dynasty, more voluminous prescription writing came out one after another and promoted the development of science of TCM formulae, such as "The Prescriptions Worth a Thousand Gold for Emergencies" and "A Supplement to the Essential Prescriptions Worth a Thousand Gold for Emergencies", compiled by Sun Simiao, and "The Medical Secrets of an Official" compiled by Wang Tao consisting of more than six thousand prescriptions. The three medical formularies representing the major achievements made before the Tang Dynasty collected famous earlier prescriptions in the previous historical periods and some foreign prescriptions used in the Tang Dynasty and preserved the materials on prescriptions. In the Song Dynasty, the government once organized outstanding physicians to compile "Peaceful Holy Benevolent Prescriptions" (with 16834 prescriptions), "General Collection for Holy Relief" (with approximately 20000 prescriptions), and "Prescription of Peaceful Benevolent Dispensary" (with 788 prescriptions). The last one was compiled on the basis of the revision and supplement to the formularies collected by the Official Pharmaceutical Bureau. It is one of the earliest formulary in the world compiled by the National Pharmaceutical Bureau. Each prescription gives interpretations in detail to its indications, ingredients and preparation of drugs. This prescription book--a "legal" formulary of Chinese patent medicines in the Song Dynasty and also the first pharmacopoeia of the Chinese patent medicines is a big step towards the standardization of prescription. 'Expounding on the Treatise on Febrile Diseases" compiled by Cheng Wuji, a physician in the Jin Dynasty, selected 20 prescriptions from the book "Treatise on Febrile Diseases" and analyzed them in detail, especially clearly described the different roles of the principal, assistant, adjuvant and guiding drugs. It is the first theoretical book on the interpretations of prescriptions and contributes a great deal to the development of theoretical prescription treatises of later periods. Dr. Zhu Su of the Ming Dynasty and others collected almost all the medical formularies having been used before the fifteenth century and compiled the most voluminous medical book "Prescriptions for Universal Relief" with as many as 61739 prescriptions in it. In the Qing Dynasty, with the emergence and development of the schools of epidemic febrile diseases came into being, enriching and perfecting the contents of pharmacology of TCM formulae. In addition, in the Ming and Qing Dynasties a lot of monographs on prescriptions were published such as "Textual Criticism on Prescriptions" and "Collection of Prescriptions with Notes," thus further promoting the development of the theoretical research of the science of TCM formulae.
Since the founding of the People's Republic of China, a great number of prescription books have come out. Many ancient prescriptions, secret prescriptions, proved prescriptions have been collected, systematized, researched and widely applied to different clinical departments; their therapeutic mechanism researches. Meanwhile a lot of new effective prescriptions have been created and the reformation in the dosage forms of prescriptions have been carried out. As a result, a new prospect in the development of science of TCM formulae has been opened up.
To sum up, the formation and development of pharmacology of TCM formulae have undergone a very long historical process from the elementary stage to the advanced one, with forms simple to complex and has gradually become an independent science with a relatively perfect theoretical system.