In the present study, a simple, stability-indicating and cost-effective reversed-phase high performance liquid chromatography (HPLC) method was developed and validated for the determination of piroxicam in commercial and masterful formulation capsules as an alternative to existing methods. The improved HPLC method was carried out on a C18 column (150 mm x 4.6 mm i.d., 5 μm), maintained at 30 °C. The mobile-phase consisted of a solution of triethylamine 0.3% pH 5.0 and acetonitrile (70:30; v/v), run at a flow rate of 1.0 mL/min and using photodiode array (PDA) detection at 248 nm. The chromatographic separation is obtained with retention time of 6.8 min, presenting adequate system suitability parameters for HPLC analysis. Validation parameters such as the specificity, linearity, matrix effect, precision, accuracy and robustness were evaluated in accordance with the ICH Q2(R1) and Brazil RDC 166/17 requirements, giving satisfactory results within the acceptable range. The proposed method was successfully validated and applied for piroxicam analysis, contributing to improve the quality control, and can be used as easy, accurate, low time-consuming alternative to pharmacopeial quantification methodology of drug.

The present work describes a first-order derivative spectrophotometric (1D-UV) method for determination of dropropizine in commercial oral solutions. The method was developed using ecologically correct solvents and validated according to International Conference on Harmonization (ICH) recommendations. The response was linear in the concentration range of 6–24 μg/mL (r = 0.9997, n = 7) at wavelength 249 nm, which was the zero crossing point of excipient solutions. The detection and quantitation limits were 0.36 and 1.18 μg/mL, respectively. The method showed adequate precision, with a relative standard deviation values lower than 1.41%. Excellent values of accuracy were obtained, with a mean value of 99.44%. The method proved to be robust by a full factorial design evaluation. It is simple, it has low cost, and it has low use of polluting reagents. Minimum environmental hazards observed and the results obtained attest to the reliability of the proposed green method, showing to be specific, linear, precise, accurate and robust. Thus, the validated 1D-UV spectrophotometric method was successfully applied to the quantitative analysis of dropropizine in oral solutions dosage forms, helping to improve quality control and to assure therapeutic efficacy.