THE DECOMPOSITION OF PHENYLMERCURIC NITRATE IN SULFACETAMIDE DROPS DURING HEAT STERILIZATION

Analytical methods have been developed which enable phenylmercuric nit rate, mercuric ion and diphenylmercury to be measured in sulphacetamid e drops. Application of these methods demonstrate that during heat ste rilization of both 10 and 30% sulphacetamide drops containing phenylme rcuric nitrate, together with disodium edetate and sodium metabisuiphi te, there is a 20-30% overall loss of phenylmercurie nitrate. This los s occurs mainly due to the phenylmercuric ion establishing an equilibr ium with equimolar amounts of mercuric ion and diphenylmercury.