Calculating Quantities From Master Formula In extemporaneous dispensing a product is prepared and usually includes several ingredients. A List of the ingredients is provided on the prescription or is obtained from a recognised reference source where the quantities of each ingredient are indicated. It may be that this 'formula' is for the quantity requested, but more often the quantities provided by the master formula have to be scaled up or down depending on the quantity of the product you wish to prepare. Recognised reference source in Sri Lanka The British pharmacopeia (BP) British Pharmaceutical Cordex (BPC) United States Pharmacopoeia (USP) European Pharmacopoiea ( Pharmacopoeia Eropeana, Ph Eur) International pharmacopoeia (Ph.l) Japanese pharmacopoeia (JP) Fromularies The British National Formulary(BNF) Sri Lanka Hospital Formulary (SLHF) Ceylon Hospital Formulary (CHF) Reducing and Enlarging Formulae In the course of p...