Validated HPTLC method for simultaneous analysis of pyrimethamine and sulphadoxine in pharmaceutical dosage forms

A simple,specific,precise,and accurate hptlc method for analysis of pyrimethamine (pyr) and sulphadoxine (sul) both in bulk drugs and tablet formulation was developed and validated. the method uses haloperidol as an internal standard (is). chromatography was performed on tlc plates with precoated silica gel 60fusing chloroform-n-butanol-acetone (6: 1.5: 2,v/v/v) as a mobile phase. densitometric evaluation was performed at 254 nm. the rf values were 0.27 for pyr,0.63 for is,and 0.75 for sul. linear regression analysis data for calibration plots revealed good linearity over the concentration ranges 100-500 ng per band for pyr and 2000-10000 ng per band for sul. the method was validated for linearity,accuracy (from 98.12 to 101.24),precision,robustness,and specificity in accordance with ich guidelines. the limits of detection and quantification for pyr were 14.15 and 43.07 ng per band; for sul,58.37 and 152.26 ng per band,respectively. statistical analysis showed the method enables repeatable and selective simultaneous analysis of these drugs in tablet formulation and routine quality control of the bulk drug raw material. © 2013 s. meena and s. m. sandhya.