Development and Validation of Stability Indicating RP-HPLC Method for Pyrimethamine, Sulfadoxine, and Artesunate Estimation in Bulk and Its Formulation Applying DOE

Abstract

Introduction: Artesunate (ART) is a prodrug used as an antimalarial agent that acts by malarial protein
damage through alkylation. Pyrimethamine (PYR) is an antiprotozoal agent that acts by interfering with the
synthesis of tetrahydrofolic acid. Sulfadoxine is a dihydropteroate synthetase inhibiter which makes difficulty
in parasite reproduction. A stability-indicating high-performance liquid chromatography (HPLC) technique
has been established for the quantification of PYR, sulfadoxin, and ART applying design of experiment.
Material and Methods: The phosphate buffer (pH 3.0):acetonitrile (80: 20) was used as the mobile phase, and
hypersil BDS C18 (250 × 4.6 mm; 4 m) column at a flow rate of 1 mL/min was used for the chromatographic
separation. The detection wavelength was set at 237 nm. The mobile phase was optimized using 32 full factorial
design. Results and Discussion: The optimized method contains the retention times of PYR, sulfadoxin, and ART
at 3.653, 4.920, and 8.310 min, respectively. The method shows a good linearity in the concentration range of
0.5–2.5 μg/mL for PYR, 10–50 µg/mL for sulfadoxin, and 4–20 µg/mL for ART. The stability study of the drugs
was performed by acid, alkali, oxidation, thermal, and photolytic degradation. Conclusion: The proposed stability
indicating HPLC method was found to be simple, specific, practical, accurate, quick, and affordable. It was
also suitable for the routine analysis, quality control, and percentage degradation of pharmaceutical preparations
containing these drugs either individually or in combination.