RESUMO
The preparation and electrochemical characterization of a carbon paste electrode modified with the N,N-ethylene-bis(salicyllideneiminato)oxovanadium (IV) complex ([VO(salen)]) as well as its application for ranitidine determination are described. The electrochemical behavior of the modified electrode for the electroreduction of ranitidine was investigated using cyclic voltammetry, and analytical curves were obtained for ranitidine using linear sweep voltammetry (LSV) under optimized conditions. The best voltammetric response was obtained for an electrode composition of 20% (m/m) [VO(salen)] in the paste, 0.10 mol L(-1) of KCl solution (pH 5.5 adjusted with HCl) as supporting electrolyte and scan rate of 25 mV s(-1). A sensitive linear voltammetric response for ranitidine was obtained in the concentration range from 9.9×10(-5) to 1.0×10(-3) mol L(-1), with a detection limit of 6.6×10(-5) mol L(-1) using linear sweep voltammetry. These results demonstrated the viability of this modified electrode as a sensor for determination, quality control and routine analysis of ranitidine in pharmaceutical formulations.
Assuntos
Carbono/química , Eletroquímica/instrumentação , Eletroquímica/métodos , Etilenodiaminas/química , Ranitidina/análise , Vanadatos/química , Eletrodos , Concentração de Íons de Hidrogênio , Oxirredução , Preparações Farmacêuticas/análise , Ranitidina/química , Reprodutibilidade dos TestesRESUMO
This paper describes an environmentally friendly method for quantitative determination of ranitidine using diffuse reflectance spectroscopy. This method is based on the reflectance measurements of the colored product produced from the spot test reaction between ranitidine and p-dimethylaminocinnamaldehyde (p-DAC), in acid medium, using filter paper as solid support. Experimental design methodologies were used to optimize the optimal conditions. All reflectance measurements were carried out at 590 nm and the linear range was from 1.42x10(-3) to 3.42x10(-2) mol L(-1), with a correlation coefficient of 0.997. The limit of detection was estimated to be 1.09x10(-3) mol L(-1) (R.S.D.=1.9%). The proposed method was successfully applied to the determination of ranitidine in commercial brands of pharmaceuticals and no interferences were observed from the common excipients in formulations. The results obtained by the proposed method were favorably compared with those obtained by an official procedure at 95% confidence level. Additionally, the method was also applied to the determination of ranitidine in human urine showing excellent recoveries (99.6-100.3%).
Assuntos
Meio Ambiente , Preparações Farmacêuticas/química , Ranitidina/análise , Urina/química , Antiulcerosos/análise , Antiulcerosos/química , Calibragem , Química Verde/métodos , Humanos , Ranitidina/química , Análise Espectral/métodos , Urinálise/métodos , Urinálise/normasRESUMO
High Performance Liquid Chromatographic (HPLC) method was applied in this study to comparatively evaluate the stability of tablets in their original package which 150 mg of Ranitidine from six different pharmaceutical laboratories in the market, according to ICH conditions for accelerated testing: 40 degrees C, 75% RH with and without light for six months. The stability at environmental conditions was evaluated for a twelve-month period, with and without light, with the same purpose. Ranitidine is widely used to treat peptic ulcer diseases. Ranitidine is susceptible to degradation under the influence of light, humidity and temperature. The chromatographic conditions were: RP-18 column of 250 mm yen 4 mm ID and a particle size of 5 mm; mobile phase of Acetonitrile-Ammonium acetate solution (0.2 M) (70:30; v/v) (pH*6) adjusted with glacial acetic acid; flow rate of 1 ml min-1; 25 degrees C of temperature; detection at 322 nm; injection volume of 20 ml, using height peak as the integration parameter. The results obtained at six months indicate that the stability of Ranitidine depends on the correct formulation and the primary container. The remaining content of Ranitidine, dissolved percentage in vitro and total impurity percentage were determined by HPLC. Organoleptic characteristics were visually examined. The proposed analytical method was validated and linearity, precision and selectivity were determined. Degradation products were detected.
Assuntos
Ranitidina/análise , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Meio Ambiente , Reprodutibilidade dos Testes , Solubilidade , ComprimidosRESUMO
El presente trabajo tiene como objetivo evaluar la utilidad de los estudios centellográficos in vitro e in vivo en el desarrollo de una formulación farmacéutica. Se eligio como trazador del proceso el radiofármaco 99mtc-ácido dietilentriaminopentaacético, que se incorporó a 4 formulaciones (f1 a f4) de comprimidos de ranitidina. Se llevaron a cabo estudios de estabilidad del radiofármaco en polvos, granulados y comprimidos. Las formulaciones en las cuales se verificó su estabilidad durante 24 horas (f2 y f4) fueronutilizadas para ensayos in vitro de disolución y desintegración y estudios en 6 voluntarios sanos. La desintegración in vitro e in vivo fué monitoreada por centellografía gamma. El radiofármaco presentó diferentes cinéticas de disolución a partir de f2 y f4, siendo las respectivas constantes que para la ranitidina en cada formulación en estudio. La centellografía permitió establecer una correlación entre las constantes de desintegración in vitro e in vivo. Esto permitiría predecir el comportamiento en el tracto gastro-intestinal de cada formulación a partir de la desintegración in vitro
Assuntos
Cintilografia/instrumentação , Ranitidina/análiseRESUMO
El presente trabajo tiene como objetivo evaluar la utilidad de los estudios centellográficos in vitro e in vivo en el desarrollo de una formulación farmacéutica. Se eligio como trazador del proceso el radiofármaco 99mtc-ácido dietilentriaminopentaacético, que se incorporó a 4 formulaciones (f1 a f4) de comprimidos de ranitidina. Se llevaron a cabo estudios de estabilidad del radiofármaco en polvos, granulados y comprimidos. Las formulaciones en las cuales se verificó su estabilidad durante 24 horas (f2 y f4) fueronutilizadas para ensayos in vitro de disolución y desintegración y estudios en 6 voluntarios sanos. La desintegración in vitro e in vivo fué monitoreada por centellografía gamma. El radiofármaco presentó diferentes cinéticas de disolución a partir de f2 y f4, siendo las respectivas constantes que para la ranitidina en cada formulación en estudio. La centellografía permitió establecer una correlación entre las constantes de desintegración in vitro e in vivo. Esto permitiría predecir el comportamiento en el tracto gastro-intestinal de cada formulación a partir de la desintegración in vitro(AU)