1. 1. United States Pharmacopeia (USP) 41 NF 36 Chapter <1231> chapter Water for Pharmaceutical Purposes, 2018; 7742-7778.
2. 2. Department of health, education, and welfare public health service food and drug administration water for pharmaceutical use. http://www. fda. gov/iceci/inspections/inspectionguides/inspectiontechnicalguides/ucm072925. htm.
3. 3. WHO good manufacturing practices: water for pharmaceutical use. Annexure -2, https://www. who. int/medicines/areas/quality_safety/quality_assurance/TRS986annex2. pdf.
4. 4. ASTM Standard Specification for Reagent Water, Designation D1193-91, In: Annual book of ASTM Standards. American Society for Testing and Materials, Philadelphia, PA. Water and Environmental Technology, 1993; 11(1): 45-47.
5. 5. Bordner R. , Winter J. and Scarpino P. (ed). Microbiological Methods for Monitoring the Environment: Water and Wastes. EPA-600/8-78-017, Environmental Monitoring and Support Laboratory, U. S. Environmental Protection Agency, Cincinnati, OH, 1978.