Development of metformin HCl granules using brown flaxseed mucilage as a retardant polymer: effects of polymer and drug ratio

Abstract Flaxseed (Linum usitatissimum L.) is the seed of a multipurpose plant of pharmaceutical interest, as its mucilage can be used as a natural matrix to develop extended-release dosage forms and potentially replace synthetic polymers. In this study, a 3² factorial design with two replicates of the central point was applied to optimize the development of extended-release granules of metformin HCl. The total fiber content of the mucilage as well as the friability and dissolution of the formulations were evaluated. The lyophilized mucilage presented a high total fiber content (42.63%), which suggests a high efficiency extraction process. Higher concentrations of the mucilage and metformin HCl yielded less friable granules. In addition, lower concentrations of metformin HCl and higher concentrations of the mucilage resulted in slower drug release during the dissolution assays. The release kinetics for most formulations were better represented by the Hixson-Crowell model, while formulations containing a higher concentration of the mucilage were represented by the Korsmeyer-Peppas model. Nonetheless, five formulations showed a longer release than the reference HPMC formulation. More desirable results were obtained with a higher concentration of the mucilage (13-18%) and a lower concentration of metformin (40%).

El efecto de los antihiperglicemiantes en los parámetros ecocardiográficos diastólicos y sistólicos / The effect of antihyperglycemic agents on diastolic and systolic echocardiographic parameters

Resumen La enfermedad metabólica diabetes mellitus tipo 2 ocasiona alteraciones en la estructura y en la funcionalidad miocárdica por diferentes mecanismos bioquímicos los cuales pueden ocasionar disfunción diastólica y sistólica, por lo cual el uso de los antihiperglicemiantes aparte de su efecto en la reducción de la hiperglicemia y la hemoglobina glicosilada, algunos han demostrado reducción en la mortalidad cardiovascular y de las hospitalizaciones por insuficiencia cardiaca, basado en estudios clínicos sobre este impacto en el miocardio. También se ha evaluado el efecto de estos fármacos por medio del ecocardiograma transtorácico. El objetivo de este articulo es analizar los valores de los parámetros ecocardiográficos sistólicos y diastólicos en pacientes diabéticos tipo 2 o alguna cardiopatía de base como antecedente de infarto al miocardio e insuficiencia cardiaca con el uso de metformina, sulfonilureas, los inhibidores de la dipeptidilpeptidasa 4 (sitagliptina, alogliptina y linagliptina, vildagliptina), los análogos de GLP1 (liraglutide, albiglutide y exenatide).

Abstract Metabolic disease type 2 diabetes mellitus causes alterations in both structure and myocardial functionality by different biochemical mechanisms which can cause diastolic and systolic dysfunction, which is why the use of antihyperglycemic agents apart from its effect in the reduction of hyperglycemia and glycosylated hemoglobin, some groups have shown reduction in cardiovascular mortality and hospitalizations for heart failure this based on clinical studies, by hypothesis, theories and pleiotropic mechanisms on this impact on the myocardium. On the other hand, the effect of these drugs on the myocardium has also been evaluated by transthoracic echocardiography. Therefore, the aim of this article is to analyze the values of systolic and diastolic echocardiographic parameters in type 2 diabetic patients or some underlying heart disease as a history of myocardial infarction and heart failure with the use of metformin, sulfonylureas, inhibitors of the dipeptidylpeptidase 4 (sitagliptin, alogliptin and linagliptin, vildagliptin), GLP1 analogues (liraglutide, albiglutide and exenatide).

Evaluación de la Calidad vs precio de comprimidos de Metformina de 850mg de producción nacional e importados, comercializados en Paraguay utilizados para el control de diabetes / Quality vs. price evaluation of national and imported 850 mg metformin tablets marketed for the control of diabetes in Paraguay

La metformina es un fármaco de primera elección, solo o combinado, en el tratamiento inicial de pacientes con diabetes tipo 2, cuya prevalencia a nivel nacional es de 8,0% en hombres y 8,3% en mujeres, con un gasto anual de 283 USD/persona. El estudio fue realizado con el objetivo de evaluar la calidad fisicoquímica y precio de comprimidos de 850 mg de metformina comercializados en nuestro país. Se analizaron medicamentos de producción nacional e importada, conteniendo 850 mg de metformina HCl, tomando como referencia la Farmacopea de los Estados Unidos (USP 38). Para evaluar la calidad de los productos se realizaron ensayos físicos químicos, además de los perfiles de disolución según el medio propuesto por la USP 38. Los resultados obtenidos se encontraron dentro de las especificaciones de valoración, entre 96% y 101% de metformina y los perfiles de disolución entre 70% y 90% de la cantidad declarada en 20 minutos, con una eficiencia de disolución (EF) entre 58% y 93%, mostrando que no existe diferencia estadísticamente significativa (p=0,41). La variación de precios encontrados fue entre 3,6 USD y 8,4 USD. Los productos analizados pueden ser intercambiables en cuanto a la calidad y los perfiles de disolución in vitro, siendo una herramienta para demostrar intercambiabilidad de productos farmacéuticos, buscando el precio más accesible en el mercado nacional y facilitando el tratamiento adecuado sobre todo para la población de escasos recursos manteniendo la calidad y eficacia del mismo(AU)

Análise comparativa de perfis de dissolução in vitro e in silico de comprimidos de liberação modificada contendo metformina / Comparative analysis of dissolution profiles in vitro and in silico of modified release tablets containing metformin

A dissolução de um fármaco a partir de uma forma farmacêutica (FF) sólida oral é um pré-requisito para que o mesmo seja absorvido pelo organismo e cumpra seus efeitos terapêuticos. O ensaio de dissolução de medicamentos permite avaliar a quantidade de princípio ativo que é liberado a partir de sua FF, mimetizando in vitro o processo que ocorre no trato gastrointestinal (TGI). O DDDPlus® é o único programa de computador dedicado exclusivamente a simular ensaios de dissolução. O objetivo deste trabalho foi avaliar a capacidade do programa de computador DDDPlus® em fornecer perfis de dissolução in silico de comprimidos matriciais contendo metformina semelhantes aos perfis de dissolução in vitro e avaliar a possibilidade de substituir a comparação de perfis de dissolução in vitro de diferentes formulações de comprimidos matriciais contendo metformina pela comparação de perfis de dissolução in silico fornecidos pelo DDDPlus®.Para tanto, um planejamento estatístico foi realizado para obtenção de perfis de dissolução, variando a velocidade das pás e o uso do sinker. Os perfis de dissolução de 3 formulações teste (T1, T2 e T3) de comprimidos de liberação modificada por matriz polimérica contendo metformina foram comparadas pelos métodos de eficiência de dissolução (ED), tempo médio de dissolução (TMD), fator de diferença (f2) e fator de semelhança (f1). Os resultados indicaram o uso do sinker como fator determinante para a ED e TMD. Assim, o método que utilizava o sinker e a velocidade das pás de 50RPM foi utilizado para avaliar 4 produtos comercializados no Brasil. No DDDPlus® os ensaios de dissolução in vitro das formulações T1, T2 e T3 foram otimizadas para a obtenção das constantes de calibração (CC), as CC foram utilizadas para simular os ensaios de dissolução de T1, T2 e T3 em velocidades de 25 e 50RPM. Os perfis de dissolução simulados foram comparados aos perfis observados, resultando em valores de R2. Valores de R2 acima de 0,90 foram obtidos para todas as simulações realizadas utilizando CC de ensaios in vitro que utilizaram sinker, indicando o potencial do programa em auxiliar o desenvolvimento de novas formulações. Valores de R2 abaixo de 0,70 foram obtidos após a simulação de ensaios utilizando CC de ensaios in vitro que não utilizavam o sinker, indicando que o programa de computador não previu a adesão do comprimido ao fundo da cuba de dissolução durante o ensaio. Os perfis de dissolução simulados das formulações T1, T2 e T3 foram comparadas por f1 e f2 com os perfis de dissolução dos produtos do mercado. Tais comparações concluíram que o software não é indicado como substituto dos ensaios in vitro quando se almeja comparar perfis de dissolução

Dissolution of a drug from an oral solid pharmaceutical form (FF) is a prerequisite for it to be absorbed by the body and to fulfill its therapeutic effects. in vitroDrug dissolution assay allows the amount of active principle released from a FF and mimics the in vivo the process that occurs in the gastrointestinal tract (TGI). DDDPlus® is the only computer program dedicated exclusively to simulating dissolution testing. The objective of this work was to evaluate the ability of DDDPlus® software to provide in silico dissolution profiles of matrix tablets containing metformin similar to in vitro dissolution profiles and to evaluate the possibility of replacing in vitro dissolution profiles comparison of different formulations of matrix tablets containing metformin for a comparison of in silico dissolution profiles provided by DDDPlus®. For this purpose, a statistical design was used, varying agitation speed and the use of sinker to obtain dissolution profiles for 3 test formulations (T1, T2 and T3) of polymer matrix-modified release tablets containing metformin. Dissolution profiles were compared by means of dissolution efficiency (ED), mean dissolution time (TMD), difference factor (f2) and similarity factor (f1). The results indicated the use of sinker as a determinant factor for ED and TMD. Thus, the method that used sinker and agitation speed of 50RPM was used to evaluate 4 products commercialized in Brazil. in vitro dissolution tests of the T1, T2 and T3 formulations were optimized using In DDDPlus® to obtain the calibration constants (CC), which were used to simulate dissolution profiles of T1, T2 and T3 at speeds of 25 and 50RPM. in silico dissolution profiles were compared to in vitro dissolution profiles, resulting in R2 values. R2 values above 0.90 were obtained for all simulations performed using CC from in vitro assays using sinker, indicating the potential of the program to assist the development of new formulations. R2 values below 0.70 were obtained after the simulation of assays using CC from in vitro assays that did not use the sinker, indicating that the computer program did not predict adhesion of the tablet to the bottom of the dissolution cell during the assay. The simulated dissolution profiles of the T1, T2 and T3 formulations were compared by f1 and f2 with the dissolution profiles of the market products. Such comparisons concluded that the software is not indicated as a substitute for in vitro assays when comparing dissolution profiles is desired

Effect of metformin on semen quality

ABSTRACT Various studies have linked metformin, a universally antidiabetic drug, with semen quality; however, such a direct link has not been established. This review systematically addresses and summarizes the effect of metformin on semen quality, particularly sperm function. We searched the MEDLINE electronic database for English articles and abstracts containing the key words 'metformin' and 'sperm', and relevant articles were reviewed. In summary, metformin appears to have improved and provided positive impact on sperm quality. This effect may be due to the ability of metformin to reduce oxidative stress and lipid peroxidation, enhance 5'-AMP activated protein kinase activity, and restore the normal levels of pituitary-gonadal hormones. However, further clinical research is still necessary to confirm such effect.

Métodos analíticos necesarios para el desarrollo de tabletas de metformina 500 mg / Analytical methods needed for Metformin 500mg tablets development

El clorhidrato de metformina es un derivado de la biguanida usado en la diabetes mellitus no insulina dependiente, reduce la concentración de glucosa sanguínea sin incrementar la secreción de insulina, se considera un agente antihiperglucemiante y no un fármaco hipoglucemiante. El desarrollo tecnológico requiere de métodos analíticos confiables que permitan la cuantificación del fármaco en diferentes etapas de la investigación. El objetivo de este trabajo fue la validación del método analítico, reportado en la Farmacopea de los Estados Unidos (USP 31, 2008), por espectrofotometría ultravioleta y la adaptación del método analítico, reportado en la misma farmacopea, para el análisis de los compuestos relacionados en la determinación del principio activo en el producto terminado, por cromatografía líquida de alta resolución, validados para el control de la calidad y estudio de estabilidad de las tabletas de metformina 500 mg. A las técnicas validadas, por métodos cromatográficos y espectrofotométricos se le determinaron los parámetros de desempeño, especificidad, linealidad, exactitud y precisión. Las curvas de calibración para cada método, se realizaron en el intervalo de 60 al 140 por ciento, donde fueron lineales con coeficientes de correlación igual a 0,9994 y 0,99903, respectivamente; la prueba estadística para el intercepto y la pendiente se consideró no significativa. Se obtuvieron recobrados de 100,01 y 99,1 por ciento, respectivamente, en el intervalo de concentraciones estudiados y las pruebas de Cochran´(G) y Student´s (t) resultaron no significativas. Los coeficientes de variación en los estudios de la repetibilidad fueron iguales a 1,4 y 0,8 por ciento, respectivamente, para las 6 réplicas ensayadas, mientras que en los análisis de la precisión intermedia las pruebas de Fischer y Student fueron no significativas. Los resultados permiten concluir que ambos métodos cumplen con los requisitos establecidos como aceptables para cada uno de los casos...

Metformin hydrochloride is a biguanide-derivative used in non-dependent insulin diabetes mellitus reducing the blood glucose concentration without increases insulin secretion, and it is considered a anti-hyperglycemia agent and not a hypoglycemia one. Technological development requires of a reliable analytical methods allowing drug quantification in different stages of research. The aim of present paper was the analytical method validation, reported in USA Pharmacopeia (USP 31,2008) by UV-spectrophotometry and the adaptation of abovementioned method reported in the same pharmacopeia, for analysis of compound related in determination of active principle in end product, by high-performance liquid chromatography validated for quality control and study of Metformin (500-mg) tablets stability. In validated techniques by chromatographic spectrophtometric methods we determined performance parameter, specificity, linearity, accuracy, and precision. Calibration curves for each method was performed in intervals of 60to 140 percent, where they were linear with correlation coefficients equal to 0.9994 and 0.99903, respectively. Statistical test for interceptor and slope was considered as non-significant. We achieved recoveries of 100.01 and 99.1, respectively during interval of study concentrations, and the Cochran (G) and Student's (t) tests were not significant. Variation coefficients in studies of repetition were equal to 1.4 and 0.8, respectively for the 6 assayed replica, whereas in average precision analysis, Fischer and Student tests were not significant. Results allow concluding that both methods fulfill the established requirements as acceptable for each of cases during the concentration interval established.

Evaluación de desempeño del método de ensayo de disolución para tabletas metformina 500 mg producidas en Cuba / Performance evaluation of the dissolution test method for metformin tablets 500 mg produced In Cuba

Se validó un método para evaluar la disolución de las tabletas de metformina 500 mg producidas en Cuba por espectrofotometría, con detección ultravioleta a 233 nm. Se evaluaron los parámetros de especificidad, linealidad, precisión e influencia de la filtración. En el estudio de la influencia de la filtración se demostró que a través del filtro de línea, no se absorbe el principio activo, ni se aportan interferencias al filtrado, por lo que se recomienda su empleo. Se demostró la especificidad del método al no observarse interferencias de los excipientes de la formulación, en la determinación del principio activo. La curva de linealidad se realizó en el intervalo de 3,0 a 7,0 µg/mL con un coeficiente de correlación igual a 0,999. El método resultó preciso ya que los valores se encontraron dentro de los límites establecidos.

We validated a method to assess dissolving of Metformin tablets (500 mg) produced in Cuba by spectrophotometry, with UV detection at 233 nm. We evaluate also the parameters of specificity, linearity, accuracy, and filtration influence. In study of this latter, we showed that through the line-filter, it is impossible to absorb the active principle and there weren't filtration interferences, recommending thus its use. We showed also method specificity because of there weren't interferences of the formula excipients, in the active principle determination. Linearity curve was established in the interval of 3,0 to 7,0 µg/mL, with a correlation coefficient similar to 0,999. Method was accurate since values were within the established limits.