1. The Common Systems

2. The common systems Apothecaries' system: -The apothecaries' system is an obsolete system formerly used by apothecaries (now called pharmacists or chemists) in English- speaking countries. Apothecaries’ fluid measure 60 minims (m) = 1 fuidrachm ( f ʒ ) 8 fluidrachms = 1 fluidounce ( f oz ) 16 fluidounces = 1 pint (pt or 0) 2 pints = 1 quart (qt) 4 quarts = 1 gallon (gal or C) Apothecaries’ measure of weight 20 grains (gr) = 1 scruple ( Э ) 3 scruples (60 grains) = 1 drachm ( ʒ ) 8 drachms (480 grains) = 1 ounce ( oz ) 12 ounces (5760 grains) = 1 pound (1b)

3. Avoirdupois system -The avoirdupois system is a system of weight based on a pound of sixteen ounces. -It is the everyday system of weight used in the United States. -It is considered more modern than the alternative apothecary system. Avoirdupois measure of weight 437.5 grains (gr) = 1 ounce ( oz ) 16 ounces (7000 grains) = 1 pound (1b) - Bulk or stock packages of powdered drugs are provided to the pharmacist in avoirdupois units of weight by manufacturers. - However, when compounding a prescription the pharmacist employs the apothecaries’ and metric systems to weigh and measure ingredients.