RESUMO
A reversed-phase high-performance liquid chromatography method was developed and validated for the simultaneous determination of pridinol, diclofenac and diclofenac-related compounds in tablet formulations. The proposed method is also suitable for content uniformity determination, for dissolution test and for stability studies. Separation was achieved on a base-deactivated silica C8 column, using 50 mM phosphate buffer (pH 2.5) and methanol (40:60 v/v) as mobile phase, at a flow rate of 1.0 mL/min and column temperature of 40°C. Ultraviolet detection was made at 225 nm. The method was validated for specificity, accuracy, precision (intraday and interday levels) and linearity for each analyte. For diclofenac impurity A, sensitivity was also studied. The method showed specificity and linearity (R2: 0.999 for the three analytes) over the assessed concentration range (diclofenac: 2.5-75.0 µg/mL, pridinol: 2.0-60.0 µg/mL and impurity A: 1.25-5.0 µg/mL) and demonstrated good precision as reflected by the low coefficient of variation in all cases. Recovery rates obtained were 99.81, 100.58 and 100.96% for diclofenac, pridinol and impurity A respectively, and for all three analytes, the variances of the concentrations tested were equivalent. The detection and quantitation limits for impurity A were 0.078 and 0.261 µg/mL, respectively.
Assuntos
Diclofenaco , Piperidinas , Cromatografia Líquida de Alta Pressão/métodos , Piperidinas/análise , ComprimidosRESUMO
The aims of the present study were to characterize for the first time the carrageenan extracted from cystocarpic stage of S. crispata collected in the Patagonian coast of Argentina, and to prepare interpolyelectrolytic complexes (IPECs) between the polysaccharide extracted from cystocarpic stage of Sarcothalia crispata and Gigartina skottsbergii thalli, and basic butylated methacrylate copolymer (Eudragit E), in order to test their potential for the controlled release of ibuprofen as model drug. The structural determination revealed that the polysaccharides extracted from S. crispata and G. skottsbergii were mainly constituted by κ-carrageenan, particularly in the case of G. skottsbergii; however, significant amounts of ι- and ν-carrageenan were also detected in both polygalactans. The differences in diad composition and possibly in their distribution along the polysaccharide chain of both carrageenans would favor a different arrangement in the resulting IPEC structure. The smaller pores observed by scanning electron microscopy in the IPEC of S. crispata suggest that the kinks in the polysaccharide backbone are evenly distributed, resulting in a slower ibuprofen release compared to the IPEC of G. skottsbergii.
Assuntos
Carragenina/química , Preparações de Ação Retardada/química , Rodófitas/química , Metilmetacrilatos/química , Estrutura MolecularRESUMO
Se ensayó la actividad antifúngica in vitro de extractos hidroalcohólicos de plantas indígenas y exóticas empleadas en la Medicina Tradicional Argentina (MT), mediante el método del pocillo en la placa de agar, contra los hongos dermatofitos Microsporum canis, Trichophyton Mentagrophytes y T. rubrum y contra la levadura Candida albicans. De las 21 especies estudiadas, 19 mostraron actividad apreciablemente mayor que el nitrato de miconazol empleado como control. Entre las especies indígenas, Tabebuia impetiginosa (Mart. ex DC) Standley, conocida como "Lapacho" y Minthostachys verticillata (Griseb.) Epl., conocida como "Peperina" mostraron la mayor actividad. Otras especies indígenas como Aloysia triphylla (L' Her.) Britton y Passiflora coerulea L. mostraron una actividad moderada.