chp02 Drug purity and its control.ppt

Chapter 2 Drug purity and  its control Section 1 The purity of drug Drug is any chemical compound that may be used on or administered to humans (or animals) as an aid in the diagnosis, treatment, or prevention of disease or other abnormal condition, for the relief of pain or suffering, or to control or improve any physiologic or pathologic condition. The purity of drug means the pure degree of drug, including physical and chemical characteristics, physical constants, impurities, content of drug. **On the other hand, the purity of drug is impurities and their limits in drug. Section 2 Impurities and  their sources 1. Impurity of drug *Impurity of drug is any (trace) foreign matter, except the active ingredients, in drug that may have: (1)?no therapeutic action and/or dangerous to human health (2)?affect therapeutic efficacy (3) affect stability of drug 2. The sources of impurities 2.1 The manufacturing process (1) the starting material and its impurities (2) intermediates side-products isomer Polymorphs decomposed products in purification (3) reagents, solvent, and catalysts used in the process (4) reaction vessels Example: ① ? ② NaCl for pharmaceutical degree impurities: Ca、Mg、Ba salts or heavy metals 2.2 The storage period (chemical and physical instability) (1)?temperature, moisture, sun light (ultraviolet), air (oxygen) etc. or microbial effects (2) hydrolysis, oxidation, decomposition, isomerization, polymorphic, polymerization etc. Example: ① degradation of Aspirin ? ② tetracycline antibiotics ? Section 3 Test of