Calamine and Coal Tar Ointment

Compound Calamine Ointment

Calamine and Coal Tar Ointment contains 12.5% w/w each of Calamine and Zinc Oxide and 2.5% w/w of Strong Coal Tar Solution in a suitable water-emulsifying basis.

The following formula and directions apply.

Calamine, finely sifted	125 g
Zinc Oxide, finely sifted	125 g
Strong Coal Tar Solution	25 g
Hydrous Wool Fat	250 g
White Soft Paraffin	475 g

Melt together the Hydrous Wool Fat and the White Soft Paraffin. Triturate the Calamine and Zinc Oxide in the melted basis and stir gently, when cooled, to about 40°. Gradually incorporate the Strong Coal Tar Solution and stir until cold.

The ointment complies with the requirements stated under Topical Semi-solid Preparations and with the following requirements.

19.8 to 22.8% w/w.

The residue obtained in the Assay is yellow when hot and white when cool.

Gently heat 1 g until the basis is completely volatilised or charred. Increase the heat until the carbon is removed and ignite the residue of ZnO until, after further ignition, two successive weighings do not differ by more than 0.2% of the weight of the residue. Each g of residue is equivalent to 0.8034 g of Zn.

Calamine and Coal Tar Ointment should be kept in a container that minimises evaporation losses.