RESUMEN
A micellar electrokinetic chromatographic (MEKC) method for the simultaneous separation and determination of lamivudine (LMV) and zidovudine (ZDV) in pharmaceutical formulation has been developed. Factors that affect the separation, such as buffer pH, surfactant concentration (sodium dodecyl sulfate, SDS), organic solvents and applied voltage were optimized. Buffer consisting of 12.5 mM sodium tetraborate decahydrate and 15 mM boric acid adjusted at pH 10.8, containing 90 mM SDS and 5% (v/v) acetonitrile (ACN) was found to be suitable for the separation of the drugs. p-Aminobenzoic acid (PABA) was used as internal standard (I.S.). Detection of analytes and I.S. was performed at a wavelength of 210 nm. It was observed that both the drugs and I.S. were migrated within 20 min at the applied voltage of +10 kV. Validation of the method was performed in terms of linearity, accuracy, precision, limit of detection (LOD) and quantification (LOQ). An excellent linearity was obtained in the concentration range 10-80 microg/ml for LMV and 10-100 microg/ml for ZDV. The detection limits for LMV and ZDV were found to be 2.5 and 2.0 microg/ml, respectively. The optimized method was applied to the simultaneous determination of LMV and ZDV in pharmaceutical formulation and human plasma (spiked) samples. Recovery of both the drugs in tablet dosage form and spiked drugs in plasma were > or =99.72% (relative standard deviation (R.S.D.)< or =1.84%) and > or =80.4% (R.S.D.< or =5.4%), respectively. In the electropherogram no interfering peaks were observed in the region of analytes and I.S. due to inactive ingredients in the tablets and matrices in plasma.
Asunto(s)
Química Farmacéutica/métodos , Cromatografía Capilar Electrocinética Micelar/métodos , Inhibidores de la Proteasa del VIH/farmacología , Lamivudine/farmacología , Preparaciones Farmacéuticas/química , Zidovudina/farmacología , Ácido 4-Aminobenzoico/química , Boratos/química , Ácidos Bóricos/química , Tampones (Química) , Cromatografía , Cromatografía Líquida de Alta Presión , Electroforesis , Concentración de Iones de Hidrógeno , Cinética , Lamivudine/química , Micelas , Modelos Químicos , Preparaciones Farmacéuticas/análisis , Presión , Reproducibilidad de los Resultados , Dodecil Sulfato de Sodio/química , Solventes/química , Factores de Tiempo , Zidovudina/químicaRESUMEN
A capillary electrophoresis (CE) method was developed for the assay determination of gabapentin (GBP) in bulk drug and capsules. Separation was carried out on 74cm (62.5cm effective length) x 75microm i.d. fused silica capillary by applying a potential of -20kV at ambient temperature. Background electrolyte (BGE) consisting of 5mM 5-sulphosalicylic acid and 0.5mM cetyltrimethylammonium bromide (CTAB), pH 11.0 was employed for the separation. Indirect method of UV detection was performed at a wavelength of 215nm using sulphosalicylate ion as a chromophore. A linear calibration curve was obtained over a concentration range 20-200microg/ml of GBP in deionized water with a correlation coefficient (r) of 0.9998. Recoveries were shown to be >/=98% both in bulk drug and capsules with standard deviation (S.D.)