A Validated RP-HPLC Stability Method for the Estimation of Chlorthalidone and Its Process-Related Impurities in an API and Tablet Formulation

Table 6

Results for the % recovery with the chlorthalidone tablets.

	% recovery
	50%			100%			150%
Stage II process impurity	100.03	98.39	98.71	99.29	99.34	99.44	99.49	100.47	100.71
Mean % recovery	99.05			99.36			100.22
SD	4689.33			815.064			10458.61
%RSD	0.8776			0.0760			0.6447
Stage III process impurity	98.91	98.89	98.60	99.45	99.63	99.91	98.80	99.22	99.66
Mean % recovery	98.25			99.62			99.23
SD	1035.37			1819.20			6980.63
%RSD	0.194			0.169			0.434