Simultaneous Assay of Dexchlorpheniramine Maleate, Betamethasone, and Sodium Benzoate in Syrup by a Reliable and Robust HPLC Method

Table 6

Results of system precision for betamethasone and dexchlorpheniramine maleate.

No. of injection	Retention time (minutes)	Peak area (mAu·s)	Asymmetry of peak	Number of theoretical plates	Resolution
Dexchlorpheniramine maleate
1	4.721	2919244	1.3	3962	5.2
2	4.708	2920606	1.3	3940	5.2
3	4.703	2922790	1.3	3932	5.2
4	4.689	2915735	1.3	3909	5.2
5	4.689	2913275	1.3	3909	5.2
6	4.689	2910823	1.3	3909	5.2
Average	4.700	2917079	1.3	3927	5.2
RSD (%)	0.3	0.2	0.1	0.6	0.3
Sodium benzoate
1	9.410	6172807	1.3	2891	9.4
2	9.413	6173718	1.3	2893	9.4
3	9.415	6171398	1.3	2894	9.4
4	9.397	6162984	1.3	2883	9.4
5	9.386	6161866	1.3	2877	9.4
6	9.377	6150875	1.3	2871	9.4
Average	9.400	6165608	1.3	2885	9.4
RSD (%)	0.2	0.1	0.1	0.3	0.2
Betamethasone
1	17.917	863391	1.1	8025	11.3
2	17.895	868096	1.1	8006	11.3
3	17.869	868453	1.1	7983	11.3
4	17.818	860990	1.1	7937	11.2
5	17.787	864537	1.1	7909	11.2
6	17.757	863288	1.1	7883	11.2
Average	17.841	864793	1.1	7957	11.3
RSD (%)	0.4	0.3	0.1	0.7	0.6