A prescription is composed of selected drugs and suitable doses based on syndrome differentiation for etiology and the composition of therapies in accordance with the principle of formulating a prescription. It serves as a chief means of treating diseases clinically.
Science of Prescriptions is a subject dealing with treatment and the theories of compatibility of prescriptions as well as the clinical application. In TCM, it is one of the important basic courses and has a close relationship with all other clinical branches, linking up the basic theories with clinical practices.
The formation of prescriptions has undergone a considerably long history. As early as in the Chinese primitive society, our ancestors discovered, while going in search of food, drugs and used them for curative purposes. Initially they only used a single drug in a dose. But through long clinical practice, they recognized that a recipe composed of two or more drugs proved more advantageous for treatment of diseases, and various prescriptions were gradually formed. Wushi'er Bingfang ( The Prescriptions for Fifty-two Kinds of Diseases ) is the oldest extantmedical formulary with a collection of over 280 prescriptions, most of which consist of less ingredients, rough dosages,
simple forms of preparations and unnamed prescriptions, all reflecting the simplicity of early prescriptions. Huangdi Neijing( Huangdi's Classic on Medicine) written in the Spring and Autumn Period and the Warring States Period, though recording only 13 prescriptions with simple ingredients, includes such dosage forms as decoction, pill, powder, ointment, pellet and medicinal liquor. Besides it summed up the theories of therapeutic principles based on syndrome differentiation, therapeutic methods, principles of formulating prescriptions as well as the incompatibility of drugs, laying a preliminary theoretical foundation for the formation and development of the science of prescriptions. The book Shanghan Zabing Lun (Treatise on Febrile and Miscellaneous Diseases ),complied by Zhang Zhongjing in the Eastern Han Dynasty,creatively merged the theories, methods, prescriptions and drugs into a single whole and is thus honored as "the forerunner of prescription books" by the later generations. The book recorded 314 prescriptions with a rigorous compatibility, precise selection of drugs and remarkable therapeutic effect. It has a far-reaching influence upon the development of this science and it is known as a "classic on prescriptions".