Нe purpose of pharmaceutical calculations is to allow the pharmacist to prepare pharmaceutical dosage forms for their patients accurately. Нere exists a need for every pharmacist to be competent in these calculations for patient’s care and safety. Some of the necessary calculations are discussed below. Aliquot method: НLs method permits the pharmacist to make measurements for powders or liquids within acceptable errors (usually 5%). Нe method relies on knowledge of the sensitivity requirement of the balance (for powders) or the deviation value of the measuring device (for liquids). НLs in turn, allows calculation of the minimum allowable quantity within a predetermined error rate. Density Factor (DF): Нe density factor determination is necessary for accurately preparing suppositories in pharmacy. It is defined as the weight of the drug in grams which occupies the same volume as that of 1 g of the base (usually cocoa butter). Нe Paddock Laboratory method is oÑ–en used for such determination of the DF value. Milliequivalent (mEq): Нe notion of mill equivalent applies to ions in solution. When ions interact with each other in solution, they do so, 1 equivalent weight to 1 equivalent weight. For example, 1 equivalent weight of calcium always reacts with 1 equivalent weight of chloride in solution. Stated otherwise, 20 g of calcium react with 35.5 g of chloride to form CaCl2 . Note that calcium chloride has 2 equivalent weights of each calcium and chloride (it contains 40 g of calcium and 71 g of chloride). MilligraUniversal Pharmaceutical Calculations: An Overview