Development and validation of RP-HPLC method for simultaneous estimation of sulfadoxine and pyrimethamine in tablet dosage form using diclofenac as internal standard

Figures & data

Figure 1. Chromatogram of a single injection of solution containing standards of sulfadoxine and pyrimethamine in a binary mixture.

Sulf—sulfadoxine, Pyr—pyrimethamine.

Table 1. Calibration curve data for sulfadoxine and pyrimethamine

Regression parameters	Sulfadoxine	Pyrimethamine
Regression equation	y = 6291.9x + 62,621	y = 33,733x + 542,203
r^2	0.9976	0.9841
Slope	6291	33733
Y-intercept	62,621	542,203
Concentration range(μg/mL)	31.25–500	31.25–500
Number of points	5	5

Table 2. Mean recovery of sulfadoxine and pyrimethamine from binary mixture

Sulfadoxine			Pyrimethamine
Amount injected (μg/mL)	Amount recovered (μg/mL)	% Recovery	Amount injected (μg/mL)	Amount recovered (μg/mL)	% Recovery
31.25	30.45	97.44	31.25	31.05	99.36
62.50	59.81	95.70	62.50	61.50	98.40
125.00	118.67	94.94	125.00	129.39	103.51
250.00	240.05	96.02	250.00	248.90	99.56
500.00	506.09	101.22	500.00	491.02	98.20
		α = 97.06			α = 99.81
		SD = 2.23			SD = 1.93
		%RSD = 2.30			%RSD = 1.93

Table 3. Summary of validation parameters of sulfadoxine and pyrimethamine

Parameters	Sulfadoxine	Pyrimethamine
Linearity (r^2)	0.9976	0.9841
Intra-day precision (%RSD)	0.0016	0.0002
Inter-day precision (%RSD)	0.0029	0.0074
LOD (μg/mL)	0.0396	0.8025
LOQ (μg/mL)	0.1201	2.4318
Accuracy (%)	97.06 ± 2.23	99.81 ± .93
Robustness	Robust	Robust
Specificity	Specific	Specific

Figure 2. Chromatogram of a single injection of solution containing standards of sulfadoxine, pyrimethamine and diclofenac (internal standard).

Sulf—sulfadoxine, Pyr—pyrimethamine, Diclo—diclofenac.

Table 4. Percent purity of sulfadoxine and pyrimethamine in tablet dosage form using external standard

Brand	API	Nominal Concentration (μg/mL)	Mean peak area	Actual Concentration (μg/mL)	Mean purity (%)
Palidar	Sulfadoxine	250.32	1,572,978.76	249.01	99.60
	Pyrimethamine	12.52	966,526.69	12.58	100.47
Maladar	Sulfadoxine	250.32	1,572,968.50	249.87	99.82
	Pyrimethamine	12.52	966,520.52	12.58	100.47

Table 5. Content of sulfadoxine and pyrimethamine in tablet dosage form using internal standard

Brand	API	Nominal conc. (μg/mL)	MPAR	Actual concentration (μg/mL)	Mean Purity (%) ± S.D.
Palidar	Sulfadoxine	250.32	0.3992	239.56	95.70 ± 0.03
	Pyrimethamine	12.52	0.2453	12.52	100.03 ± 0.22
Maladar	Sulfadoxine	250	0.4099	246.25	98.50 ± 0.15
	Pyrimethamine	12.52	0.2450	12.49	99.75 ± 0.25

Figure 3. A plot of MPAR versus concentrations of sulfadoxine.

Figure 4. A plot of MPAR versus concentrations of pyrimethamine.