Development of stability indicating method for the simultaneous estimation of alogliptin and pioglitazone in bulk and tablet dosage form by reversed-phase ultra-performance liquid chromatography method

The objective of the work is to develop and validate a new reverse phased ultra-performance chromatography method and its stability studies for the simultaneous estimation of alogliptin and pioglitazone in bulk and tablet dosage form. The column of the method was BEH C18 (2.1× 50 mm, 1.7 µ) used as a stationary phase and the mobile phase was 45:55 v/v of phosphate buffer (pH 3) and methanol, respectively. The injection volume was 2 µl and flow rate was maintained at 0.3 ml/minute. The wavelength was 280 nm and the runtime was 3 minutes. The retention time of alogliptin was 0.4 minutes and pioglitazone was 0.529 minutes. The Linearity of the alogliptin was 6.25–37.5 µg/ml and pioglitazone was 15–90 µg/ml. The newly developed method could be used for the routine analysis of pure drug and its formulations in accordance with the ICH Q2 (R1) guidelines.

Effect of PEG400 Concentration in Receiving Solution on Drug Transdermal Test in Vitro / 中国实验方剂学杂志

Objective: To investigate the effect of varying concentrations of polyethylene glycol(PEG)400 in receiving solution on in vitro transdermal test of drugs. Method: 5-Fluorouracil(5-FU) was selected as a model drug,by preparing different concentrations of PEG400-phosphate buffer solution(PBS) as the receiving solution,the receiving chamber did not add drug,the excised rat skins were treated with various additives for 12 h,then replaced by PBS and added the saturated model drug into the donor compartment to determine the transdermal parameters of the drug.Meanwhile,scanning electron microscopy(SEM) was employed to monitor the effect of PEG400 with different concentration on the stratum corneum of rat skin. Result: The 10%,15% and 40% PEG400-PBS groups had no significant effect on in vitro transdermal absorption parameters of the 5-FU.The steady transdermal rate and cumulative penetration rate of the drug in 20% and 30% PEG400-PBS groups were significantly higher than that in the PBS group(PPConclusion: In the rat skin transdermal test,the concentration of PEG400 in receiving solution should be controlled below 20%.

Extractive colorimetric method development and validation for erlotinib in bulk and tablet dosage form.

Two simple, rapid, sensitive, precise and economic spectrophotometric methods have been developed for the estimation of Erlotinib in bulk and tablet formulation. During the course of study, it was observed that solution of the drug formed colored ion-pair complexes with Bromocresol Green (BCG) and Methyl Orange (MO) in phosphate buffer pH 2.5, and extracted in chloroform. This property of the drug was followed for the development of colorimetric methods for analysis of drug. The complex of etoricoxib with BCG and MO showed λ max at 418.5 nm and 424.4 nm respectively. The complex was stable up to 22 hrs and obeyed Beer's law over the concentration ranges of 10-1000 μg/ml. Correlation coefficient was found to be 0.9985. In addition we have determined the molar absorptivity, Sandell sensitivity and the optimum conditions for quantitative analysis of erlotinib. These methods were validated statistically. Recovery studies gave satisfactory results indicating that none of common additives and excipients interfere the assay method. The proposed methods are found to be simple, accurate and reproducible that was successfully applied for the analysis of tablet formulation.

A validated stability indicating HPLC method for the determination of Valsartan in tablet dosage forms.

A simple, specific, rapid, precise and robust HPLC method has been developed for the quantitation of valsartan in tablet dosage form on a C18 column (250 x 4.6 mm) using a mobile phase consisting of ammonium dihydrogen phosphate buffer : methanol (33.5:66.5) adjusted to pH 3 with formic acid at a flow rate of 1.0 ml/min and detection at 265 nm. The retention time of valsartan was found to be at 11.9 min. The validation of above method was also done. Percentage label claim of the tablet formulations were found to be 100.8%. So the proposed method provides a faster and cost effective quality control tool for routine analysis of valsartan from formulations.

Fator capacidade de fósforo em solos de pernambuco mineralogicamente diferentes e influência do pH na capacidade máxima de adsorção / Phosphate capacity factor in mineralogically different soils in Pernambuco and the influence of pH on the maximum capacity of adsorption

O Fator Capacidade de Fósforo (FCP) é definido pela razão de equilíbrio entre o fator quantidade de P (Q) e o fator intensidade (I) e representa uma medida da capacidade do solo em manter um determinado nível de P em solução. As características e o teor dos constituintes minerais da fração argila são responsáveis por uma maior ou menor FCP, interferindo nas relações solo-planta. Por outro lado, o pH do solo tem, em alguns casos, mostrado-se com efeito na adsorção e, em outros, com pequena e não consistente alteração na Capacidade Máxima de Adsorção de P (CMAP). Objetivou-se, neste trabalho, determinar o FCP de solos mineralogicamente diferentes em Pernambuco; correlacionar características físicas e químicas dos solos com o FCP; e avaliar o efeito do pH na CMAP. Amostras subsuperficiais de quatro solos, mineralogicamente diferentes, foram caracterizadas química e fisicamente e determinado o FCP. Essas amostras foram corrigidas com CaCO3 e MgCO3 na proporção 4:1 e incubadas por 30 dias, com exceção do Vertissolo. Determinou-se a CMAP antes e após a correção dos solos. O experimento consistiu de um fatorial 4 x 2 (quatro solos com e sem correção), distribuídos em blocos ao acaso, com três repetições. As características dos solos que melhor refletiram o FCP foram o P remanescente (P-rem) e a CMAP. Independentemente dos constituintes mineralógicos da fração argila, solos com elevados teores de alumínio apresentaram aumento da CMAP com a correção. A energia de adsorção (EA) nos solos corrigidos foi, em média, significativamente menor, independentemente do solo.

Phosphate Maximum Capacity (FCP) is defined by the ratio of equilibrium between the amount of factor P (Q) and factor intensity (I) and represents a measure of the soil ability to maintain a certain level of P in solution. The characteristics and content of the constituents of clay minerals are responsible for a greater or lesser FCP, interfering in soil-plant relations. Moreover, the soil pH has affected adsorption, and in other cases, it has shown small and inconsistent change in the maximum adsorption capacity of P (CMAP). Thus, this study aimed to determine the different FCP soil mineralogy in Pernambuco; to correlate physical and chemical characteristics of soils with PBC and to evaluate the effect of pH on the CMAP. Subsurface soil samples from four different soils were characterized chemically and physically determined, and the PBC was determined. These samples were corrected with CaCO3 and MgCO3 in a 4:1 ratio and incubated for 30 days, except the Vertisol. The CMAP was determined before and after correction of the soil. The experiment consisted of a 4 x 2 factorial (four soils with and without correction), distributed in randomized blocks with three replicates. Soil characteristics that best reflected the PBC were the remaining P (P-rem) and MPAC. Regardless of the constituents of clay mineralogy, soil with high aluminum levels had increased CMAP after correction. The energy of adsorption (EA) in the limed soils was on average significantly lower, regardless of the soil.

Development and validation of dissolution method for carvedilol compression-coated tablets

The present study describes the development and validation of a dissolution method for carvedilol compression-coated tablets. Dissolution test was performed using a TDT-06T dissolution apparatus. Based on the physiological conditions of the body, 0.1N hydrochloric acid was used as dissolution medium and release was monitored for 2 hours to verify the immediate release pattern of the drug in acidic pH, followed by pH 6.8 in citric-phosphate buffer for 22 hours, to simulate a sustained release pattern in the intestine. Influences of rotation speed and surfactant concentration in medium were evaluated. Samples were analysed by validated UV visible spectrophotometric method at 286 nm. 1 percent sodium lauryl sulphate (SLS) was found to be optimum for improving carvedilol solubility in pH 6.8 citric-phosphate buffer. Analysis of variance showed no significant difference between the results obtained at 50 and 100 rpm. The discriminating dissolution method was successfully developed for carvedilol compression-coated tablets. The conditions that allowed dissolution determination were USP type I apparatus at 100 rpm, containing 1000 ml of 0.1N HCl for 2 hours, followed by pH 6.8 citric-phosphate buffer with 1 percent SLS for 22 hours at 37.0 ± 0.5 ºC. Samples were analysed by UV spectrophotometric method and validated as per ICH guidelines.

O presente estudo descreve o desenvolvimento e a validação de método de dissolução para comprimidos revestidos de carvedilol. O teste de dissolução foi efetuado utilizando-se o aparelho para dissolução TDT-06T. Com base nas condições fisiológicas do organismo, utilizou-se ácido clorídrico 0,1 N como meio de dissolução e a liberação foi monitorada por 2 horas para se verificar o padrão de liberação imediata do fármaco em condições de pH baixo, seguidas por pH 6,8 em tampão cítrico-fosfato por 22 horas, para simular o padrão de liberação controlada no intestino. Avaliou-se a influência da velocidade de rotação e a concentração de tensoativo no meio. As amostras foram analisadas por método espectrofotométrico UV-visível validado, em 286 nm. O laurilsulfato sódico a 1 por cento (SLS) mostrou-se ótimo para aumentar a solubilidade do carvedilol em pH 6,8 em tampão cítrico-fosfato. A análise da variância não mostrou diferença significativa entre os resultados obtidos a 50 e a 100 rpm. O método da dissolução discriminante foi desenvolvido com sucesso para os comprimidos revestidos de carvedilol. As condições que permitiram a determinação da dissolução foram: aparelho USP tipo I a 100 rpm, contendo 1000 mL de HCL 0,1 N por 2 horas, seguido de pH 6,8 com tampão cítrico-fosfato, com 1 por cento de SLS por 22 horas a 37,0 ± 0,5 ºC. Amostras foram analisadas por método espectrofotométrico e validadas pelas normas ICH.