Common system

COMMON SYSTEM

In common system, there are two types.

  • Avoirdupois system
  • Apothecaries system

Avoirdupois system

  • This system is also called Imperial system. This system is widely used in the United Kingdom.
  • It is used in bulk preparation of drugs and not in the routine prescription writing.
  • In this system solids should be prescribed in grains (gr) and ounces (oz) and liquids in minims (m) and fluid ounces (fl.oz).
  • In this system Arabic numerals and abbreviation are used. Eg: Sixty grains be written as 60 gr.

Apothecaries system

  • This system is used in prescription writing. The weights under apothecaries system are known as troy weights and measures are known as wine measures.
  • Whenever apothecaries system is used the symbol should be written first followed by the number or quantity in Roman numerals (for example 4 drachm = iv 1 scruple = i).
  • Whenever, fluid measures are being used, the word ‘fl’ is written in front. The fluid measures are identical in both Apothecaries and Avoirdupois system.
Last modified: Thursday, 26 April 2012, 7:01 AM