Development and Validation of an HPLC Method for Simultaneous Assay of Potassium Guaiacolsulfonate and Sodium Benzoate in Pediatric Oral Powder

Table 11

Results of stability studies.

Studies	Average retention time (minutes)		Average peak area (mAu·s)		Average asymmetry of peak		Average number of theoretical plate		RSD (%) of peak area		Recovery (%)
	Peak 1	Peak 2	Peak 1	Peak 2	Peak 1	Peak 2	Peak 1	Peak 2	Peak 1	Peak 2	Peak 1	Peak 2
Potassium guaiacolsulfonate
Standard solution
0 h	5.633	6.734	1607838	588052	0.92	0.91	2030	2902	0.03	0.04	—	—
24 h at refrigerator	5.636	6.734	1607531	587210	0.92	0.90	2032	2902	0.03	0.05	100.0	99.9
24 h at 25°C	5.629	6.731	1606491	585247	0.92	0.91	2028	2899	0.02	0.02	99.9	99.5
Sample solution
0 h	5.630	6.736	1605436	585067	0.93	0.90	2028	2903	0.01	0.01	—	—
24 h at refrigerator	5.631	6.730	1604722	584850	0.93	0.91	2029	2898	0.02	0.01	100.0	100.0
24 h at 25°C	5.629	7.735	1603874	583290	0.92	0.91	2027	2902	0.05	0.05	99.9	99.7
Sodium benzoate
Standard solution
0 h	12.380		1906212		0.99		27250		0.06		—
24 h at refrigerator	12.372		1905065		0.98		27214		0.02		99.9
24 h at 25°C	12.366		1903771		0.99		27186		0.01		99.9
Sample solution
0 h	12.375		1904980		0.99		27226		0.01		—
24 h at refrigerator	12.381		1904544		0.99		27249		0.02		100.0
24 h at 25°C	12.367		1903276		0.99		27192		0.01		99.9