Suttikan SonchaiChutima PhechkrajangPiyanuch RojsangaMahidol UniversityFaculty of Pharmacy2022-08-042022-08-042021-01-01Pharmaceutical Sciences Asia. Vol.48, No.6 (2021), 557-56625868470258681952-s2.0-85119929056https://repository.li.mahidol.ac.th/handle/20.500.14594/78553Simultaneous determination of paracetamol and orphenadrine citrate by high-performance liquid chromatographic (HPLC) and chemometric-assisted spectroscopic methods are described. The HPLC method was based on RP C18 column (5 µm, 4.6 mm × 150 mm) using monobasic ammonium phosphate, methanol, and acetonitrile (400:450:150v/v/v) as a mobile phase. The flow rate was set at 1.5 mL/min with column temperature at 40°C and UV detection at 215 nm. Paracetamol and orphenadrine citrate were separated within 7 mins by an isocratic elution. Good linearities were obtained in concentration ranges of 5–150 µg/mL for paracetamol and 0.8–12 µg/mL for orphenadrine citrate, with correlation coefficients (r)>0.99. Recovery of the analytical method was acceptable (102.8–104.8% for paracetamol and 92.4–102.3% for orphenadrine citrate). Relative standard deviations (RSDs) of repeatability and intermediate precision were less than 2.0%. Likewise, the resolution has been completed by using partial least square regression applying UV spectrum. The successive partial least squares regression (PLSR) methods were used with UV spectra data of 200–400 nm and 5 latent factors for paracetamol and orphenadrine citrate. Finally, the developed methods proved to be suitable to assay the dissolution samples of paracetamol and orphenadrine citrate in the combination tablet.Mahidol UniversityMedicinePharmacology, Toxicology and PharmaceuticsArticleSCOPUS10.29090/psa.2021.06.21.017