Isocratic RP-HPLC Method Development, Validation, and Optimization of BCS-II in Bulk and Dosage Form

Background:: Previous studies of dextromethorphan hydrobromide basically worked on simultaneous research with other compounds. So, the development of a novel method using the isocratic elution mode is needed. Objective:: For the detection of dextromethorphan hydrobromide (DXM) in diverse matrices, a straightforward, accurate, and sensitive reversed-phase HPLC technique using a Waters 2487 Dual λ Absorbance detector has been designed and validated. Method:: In this experimental work, utilizing methanol/pH 3.0 potassium dihydrogen phosphate buffer (70:30, v/v) as the mobile phase, the separation was completed in 7 minutes on a C-18 HPLC column (4.6 cm length, 4.6 mm internal diameter; 5 μm particle size) utilizing an isocratic elution mode, flow rate of 1.0 mL/min, and UV-detection at 278 nm. Integration of the chromatography response was carried out using Empower 2.4 software Results:: With an R2 of 0.9987, the current approach showed high linearity for DXM in the 10- 60 ppm range (retention time 4.281 ± 0.505 min). For DXM Hbr, the limits of detection (LOD & LOQ) were 10.633 μg/mL and 32.221μg/mL, respectively. Samples remained stable in the presence of the matrices without any apparent influence. Conclusion:: The novel approach, which used a straightforward liquid/liquid extraction procedure with recovery ranging from 100 ± 10 % performed by two different analytes, was accurate. The precision within and between days was ≤ 2.0% (RSD). The technique was proven to be reliable and repeatable, and it can be utilized with pharmacological (active ingredients, syrups) and also for biological (blood) matrices which can be used in future research work for bioanalytical method development such as pharmacokinetics studies.