Calamine
Formula: ZaCO3. Zn(OH)2. xFe2O3 (BP) or Zn0. xFe2O3 (USP)
Calamine USP
- Calamine is Zinc Oxide with a small proportion of ferric oxide.
- Calamine contains not less than 98.0 % and not more than 100.5 % of ZnO, calculated on the ignited basis.
- Zn0. xFe2O3
Calamine BP
- As per British Pharmacopoeia (BP), Calamine is basic zinc carbonate with a small proportion of ferric oxide.
- Calamine contains not less than 98.0 % and not more than 100.5 % of ZnO, calculated on the ignited basis.
- ZaCO3. Zn(OH)2. xFe2O3
IP
- Calamine is Zinc Oxide with a small proportion of ferric oxide.
- Calamine contains not less than 98.0 % and not more than 100.5 % of ZnO, calculated on the ignited basis.
- Zn0. xFe2O3
Calamine BP is a basic zinc carbonate (ZaCO3. Zn(OH)2. xFe2O3)coloured with ferric oxide (Fe2O3) i.e. whereas calamine USP/IP is Zin oxide (ZnO) with a small proportion of ferric oxide (Fe2O3).
The presence of ferric oxide gives a pink colour for cosmetic reasons.
The tern calamine besides being applied to the official product is also used to describe the impure native zinc carbonate.
Aqueous Calamine Cream
Aq. Calamine cream contains not less than 6.30 and not more than 7.67 per cent w/w of ZnO.
Calamine Lotion
Calamine lotion contains an equal quantity of calamine & zinc oxide suspended with the aid of Bentonite Magma in a solution of Calcium Hydroxide. Calamine lotion contains 1 % liquified phenol which provides a local anaesthetic, antiseptic & antipruritic (anti-itching) action apart from antiseptic action.
Pingback: Types of Suppository bases: Pharmacy Notes| GPAT, DI | The Pharmapedia