Validation of high-performance liquid chromatography methods for determination of zidovudine, stavudine, lamivudine and indinavir in human plasma.

OBJECTIVE: Simple methods for the determination of zidovudine (AZT), stavudine (d4T), lamivudine (3TC) and indinavir (INV) in human plasma by reversed-phase liquid chromatography (HPLC) with UV detection were described and validated. METHOD: Solid-liquid extraction procedures were applied to the samples prior to analysis. Chromatography was performed on a C-18 analytical columns and the retention time ranged from 6.8 to 8.0 min for stavudine, 7.5 to 9.0 min for lamivudine, 11.2 to 11.9 min for zidovudine and indinavir. Four methods were validated for specificity, inter-and intra-assay precision and accuracy, absolute recovery and stability. RESULTS: Analytical curve ranged from 10-1600 ng/ml for stavudine, 50-3200 ng/ml for lamivudine, 0.05-5.0 microg/ml for zidovudine and 0.1-10.0 microg/ml for indinavir. Analytes stability during sampling processing and storage were established. Extraction recoveries are higher than 89% for all formulations. CONCLUSIONS: These methods proved to be simple, accurate and precise, and are currently in use in our laboratory for the quantitative analysis of antiretrovirals products in plasma, and for further pharmacokinetics and bioequivalence studies.

Bioequivalence study of two nevirapine tablet formulations in human-immunodeficiency-virus-infected patients.

OBJECTIVE: The present study describes the determination of the bioequivalence of two different nevirapine tablet formulations (nevirapine tablets 200 mg, Novatec, as the test formulation vs. viramune tablets 200 mg, Boehringer Ingelheim, as the reference formulation). METHOD: A single 200 mg oral dose of each preparation was administered to 11 human immunodeficiency virus (HIV)-infected patients volunteers and their bioequivalence was assessed by comparing the both plasma nevirapine concentrations-time curves and others pharmacokinetic parameters. RESULTS: The pharmacokinetic parameters obtained for each formulation were the area under the time-concentration curve from 0 to 12 h (AUC(0-12)) and from 0 to infinity (AUC(0-infinite)), maximum concentration (C(max)), and the time at which it occurred (T(max)). These parameters were determined by high-performance liquid chromatography (HPLC). No significant differences were observed in these parameters. The 90% confident interval for the ratio of means for the lnAUC(0-12 T/R) (0.92-1.10), lnAUC(0-infinite T/R) (0.86-1.17) and lnC(max T/R) (0.71-1.38) are within the guideline range of bioequivalence (0.80 to 1.25 and 0.70 to 1.43). For T(max) the mean of test formulation is in the range 2.64 +/- 0.53 h. CONCLUSIONS: The results show that the formulations were bioequivalent in the extent and in the rate of absorption.

Validation of high-performance liquid chromatography methods for determination of zidovudine, stavudine, lamivudine and indinavir in human plasma

Objetivo: Fueron descritos y validados métodos analíticos simplespara la determinación de zidovudina (AZT), estavudina (d4T),lamivudina (3TC), e indinavir (INV) en plasma humano por cromatografíalíquida de alta resolución (HPLC) con detección UV.Método: Se aplicó la extracción en fase sólida para la preparaciónde las muestras previo al análisis. La corrida cromatográficase realizó en una columna analítica C-18 y el tiempo de retenciónse movió en un rango de 6,8-11,9 min para d4T, 7,5-9,0para 3TC y 11,2-11,9 para AZT e INV. Se validaron 4 métodosen cuanto a especificidad, precisión y exactitud entre días y en eldía, así como recobrado y estabilidad.Resultados: Los rangos de concentraciones de las curvasanalíticas eran de 10-1600 ng/ml para d4T, 50-3200 ng/ml para3TC, 0,05-5,0 ìg/ml para AZT y 0,1-10,0 ìg/ml para INV. Sedemostró la estabilidad del analito durante el procesamiento de lasmuestras y el almacenamiento. Para las 4 formulaciones los resultadosdel por ciento de recobrado fue superior al 89%.Conclusiones: Estos métodos demostraron ser simples, exactos,precisos y son los utilizados actualmente en nuestro laboratoriopara el análisis cuantitativo de productos antirretrovirales enplasma, así como para posteriores estudios de farmacocinética ybioequivalencia

Objective: Simple methods for the determination of zidovudine(AZT), stavudine (d4T), lamivudine (3TC) and indinavir (INV)in human plasma by reversed-phase liquid chromatography(HPLC) with UV detection were described and validated.Method: Solid-liquid extraction procedures were applied tothe samples prior to analysis. Chromatography was performed ona C-18 analytical columns and the retention time ranged from 6.8to 8.0 min for stavudine, 7.5 to 9.0 min for lamivudine, 11.2 to11.9 min for zidovudine and indinavir. Four methods were validatedfor specificity, inter-and intra-assay precision and accuracy,absolute recovery and stability.Results: Analytical curve ranged from 10-1600 ng/ml forstavudine, 50-3200 ng/ml for lamivudine, 0.05-5.0 ìg/ml forzidovudine and 0.1-10.0 ìg/ml for indinavir. Analytes stabilityduring sampling processing and storage were established. Extractionrecoveries are higher than 89% for all formulations.Conclusions: These methods proved to be simples, accurateand precise, and are currently in use in our laboratory for thequantitative analysis of antiretrovirals products in plasma, and forfurther pharmacokinetics and bioequivalence studies

Bioequivalence study of two nevirapine tablet formulations in human immunodeficiency virus-infected patients / No disponible

Objetivo: En el siguiente estudio se muestra la determinación de bioequivalencia de dos formulaciones diferentes de tabletas de nevirapina (NVP) –tabletas de NVP de 200 mg, de los laboratorios Novatec, como la formulación de prueba (P) vs. las tabletas de Viramune® de 200 mg, de Boehringer Ingelheim, como la formulación de referencia (R)–. Método: Una dosis única de 200 mg de cada formulación fue administrada a 11 pacientes-voluntarios infectados con el VIH y se determinó la bioequivalencia entre ambas formulaciones por comparación de las curvas de concentración-tiempo y de otros parámetros farmacocinéticos medidos en plasma de estos pacientes para ambos productos. Resultados: Los parámetros farmacocinéticos obtenidos para cada formulación fueron área bajo la curva de concentración en el tiempo de estudio e infinita (AUC0-12 y AUC0−∞), concentración máxima (Cmax) y tiempo para alcanzar la concentración máxima (Tmax). Estos parámetros fueron determinados por cromatografía líquida de alta resolución (HPLC). No se observaron diferencias significativas en los parámetros para ambas formulaciones. En el intervalo de confianza de 90% la razón de las medias de lnAUC0-12 P/R (0,92- 1,10), lnAUC0−∞ P/R (0,86-1,17) y lnCmax P/R (0,71-1,38) están dentro de los rangos establecidos de bioequivalencia (0,80-1,25 ó 0,70- 1,43). Para Tmax, la media de la formulación de prueba se encuentra dentro del rango 2,64 ± 0,53 h. Conclusiones: Los resultados muestran que ambas formulaciones son bioequivalentes en cuanto a la magnitud y velocidad de la absorción

Objective: The present study describes the determination of the bioequivalence of two different nevirapine tablet formulations (nevirapine tablets 200 mg, Novatec, as the test formulation vs. viramune tablets 200 mg, Boehringer Ingelheim, as the reference formulation). Method: A single 200 mg oral dose of each preparation was administered to 11 human immunodeficiency virus (HIV)-infected patients volunteers and their bioequivalence was assessed by comparing the both plasma nevirapine concentrations-time curves and others pharmacokinetic parameters. Results: The pharmacokinetic parameters obtained for each formulation were the area under the time-concentration curve from 0 to 12 h (AUC0-12) and from 0 to infinity (AUC0−∞), maximum concentration (Cmax), and the time at which it occurred (Tmax). These parameters were determined by high-performance liquid chromatography (HPLC). No significant differences were observed in these parameters. The 90% confident interval for the ratio of means for the lnAUC0-12 T/R (0.92-1.10), lnAUC0−∞ T/R (0.86-1.17) and lnCmax T/R (0.71-1.38) are within the guideline range of bioequivalence (0.80 to 1.25 and 0.70 to 1.43). For Tmax the mean of test formulation is in the range 2.64 ± 0.53 h. Conclusions: The results show that the formulations were bioequivalent in the extent and in the rate of absorption

Bioequivalence study of two nevirapine tablet formulations inhuman immunodeficiency virus-infected patients

OBJECTIVE: The present study describes the determination of the bioequivalence of two different nevirapine tablet formulations (nevirapine tablets 200 mg, Novatec, as the test formulation vs. viramune tablets 200 mg, Boehringer Ingelheim, as the reference formulation). METHOD: A single 200 mg oral dose of each preparation was administered to 11 human immunodeficiency virus (HIV)-infected patients volunteers and their bioequivalence was assessed by comparing the both plasma nevirapine concentrations-time curves and others pharmacokinetic parameters. RESULTS: The pharmacokinetic parameters obtained for each formulation were the area under the time-concentration curve from 0 to 12 h (AUC(0-12)) and from 0 to infinity (AUC(0-infinite)), maximum concentration (C(max)), and the time at which it occurred (T(max)). These parameters were determined by high-performance liquid chromatography (HPLC). No significant differences were observed in these parameters. The 90% confident interval for the ratio of means for the lnAUC(0-12 T/R) (0.92-1.10), lnAUC(0-infinite T/R) (0.86-1.17) and lnC(max T/R) (0.71-1.38) are within the guideline range of bioequivalence (0.80 to 1.25 and 0.70 to 1.43). For T(max) the mean of test formulation is in the range 2.64 +/- 0.53 h. CONCLUSIONS: The results show that the formulations were bioequivalent in the extent and in the rate of absorption(AU)

Objetivo: En el siguiente estudio se muestra la determinaciónde bioequivalencia de dos formulaciones diferentes de tabletas denevirapina (NVP) –tabletas de NVP de 200 mg, de los laboratoriosNovatec, como la formulación de prueba (P) vs. las tabletas deViramune® de 200 mg, de Boehringer Ingelheim, como la formulaciónde referencia (R)–.Método: Una dosis única de 200 mg de cada formulación fueadministrada a 11 pacientes-voluntarios infectados con el VIH yse determinó la bioequivalencia entre ambas formulaciones porcomparación de las curvas de concentración-tiempo y de otrosparámetros farmacocinéticos medidos en plasma de estos pacientespara ambos productos.Resultados: Los parámetros farmacocinéticos obtenidos paracada formulación fueron área bajo la curva de concentración en eltiempo de estudio e infinita (AUC0-12 y AUC0−∞), concentración máxima(Cmax) y tiempo para alcanzar la concentración máxima (Tmax).Estos parámetros fueron determinados por cromatografía líquida dealta resolución (HPLC). No se observaron diferencias significativasen los parámetros para ambas formulaciones. En el intervalo deconfianza de 90% la razón de las medias de lnAUC0-12 P/R (0,92-1,10), lnAUC0−∞ P/R (0,86-1,17) y lnCmax P/R (0,71-1,38) están dentrode los rangos establecidos de bioequivalencia (0,80-1,25 ó 0,70-1,43). Para Tmax, la media de la formulación de prueba se encuentradentro del rango 2,64 ± 0,53 h.Conclusiones: Los resultados muestran que ambas formulacionesson bioequivalentes en cuanto a la magnitud y velocidad de la absorción(AU)