EP 8.0 monograph: impurity determination of hydrochlorothiazide using a C18 selectivity HPLC column

Instrument Type: HPLC

The separation was performed on a Thermo Scientific Hypersil Gold column using the method described in the EP 8.0 monograph. The results obtained for resolution and relative retention time (RRT) exceeded the criteria stated in the EP. Resolution between Hydrochlorothiazide and impurity A was 5.7 (EP criteria of not less than 2.5). RRT of impurity A, B and C with reference to Hydrochlorothiazide was 0.9 for impurity A, 0.7 for impurity B and 2.9 for Impurity C (EP criteria about 0.9, 0.7 and 2.8 respectively for impurity A, B and C).