Open Access Original Research Article

Creatine Supplementation in Wistar Rats Submitted to Physical Tests of Swimming: Evaluation of the Physiological Effects through Raman Spectroscopy

Humberto Miranda, Jefferson da Silva Novaes, Renato Aparecido de Souza, Diego Pereira Jerônimo, Wellington Ribeiro, Maira Gaspar Tosato, Roberto Simão, Airton Abrahão Martin, Leonardo Marmo Moreira

Journal of Pharmaceutical Research International, Page 19-28
DOI: 10.9734/BJPR/2011/236

Creatine is a nitrogenous organic acid that naturally occurs in vertebrates. This compound is associated to energy supply to muscles, being that its biological synthesis occurs mainly in liver and is related to the aminoacids glycine, arginine and ornitine. Several studies have shown the benefits of creatine supplementation, such as higher muscle power, increased fat-free mass, and strength in healthy subjects. Besides, it can be applied as therapeutic agent for some diseases. In this work, the physical condition of Wistar rats that received creatine supplementation is compared with individuals without any supplementation. For this evaluation, swimming tests were developed in order to elucidate the physical condition of animals in different nutritional conditions. Indeed, swimming is considered one of the most complete exercises, since the practice of this physical activity involves great increase in the aerobic and anaerobic capability. Raman spectroscopy was employed to analyse the biochemical profile of the biological tissues obtained from the animals evaluated in the experiments. The present results allow to infer that the association of these two factors, i.e., the addition of creatine supplementation together with physical activity, propitiates a completely different physiological effect when compared with the isolated action of each one of these factors (creatine supplementation and physical activity). In fact, these factors seem to act in synergy, favoring a more accentuated physiological response. In fact, the data obtained in this work denotes that the physical activity, as well as the creatine supplementation, when used independently, does not provoke a very significant physiological effect. Raman spectroscopy was able to analyze important biological indicators, such as protein concentration in blood and intensity of metabolic activity, being an interesting option to similar biophysical evaluations.

Open Access Original Research Article

Formulation and Evaluation of Sustained Release Matrix Tablets of Metformin Hydrochloride Using pH Dependent and pH Independent Methacrylate Polymers

Kamlesh J. Wadher, Rajendra B. Kakde, Milind J. Umekar

Journal of Pharmaceutical Research International, Page 29-45
DOI: 10.9734/BJPR/2011/255

Metformin hydrochloride is recommended globally as first line therapy due to its favorable profile on morbidity and mortality associated with type-2 diabetes mellitus. However, limitations of multiple dosing and risk of triggering gastrointestinal symptoms make its dose optimization difficult. Extended-release metformin matrix tablets were prepared by direct compression of drug and different pH-dependent (Eudragit L-100 and S-100) and pH-independent (Eudragit RLPO and RSPO) polymer combinations. The influence of varying the polymer/polymer (w/w) ratio was evaluated. Among the different examined polymer blends, matrix tablets based on S-100/RLPO and S-100/RSPO mixtures gave the more sustained release pattern. The excipients used in this study did not alter physicochemical properties of the drug, as tested by Fourier transform Infrared Spectroscopy and the thermal analysis using differential scanning calorimetry. All the batches were evaluated for thickness, weight variation, hardness, and drug content uniformity. The in vitro drug dissolution study was carried out using USP 22 apparatus II, paddle method and the release mechanisms were explored. Mean dissolution time is used to characterize drug release rate from a dosage form and indicates the drug release retarding efficiency of polymer. Kinetic modeling of in vitro dissolution profiles revealed the drug release mechanism ranges from diffusion controlled to anomalous type. Fitting the data to Korsmeyer equation indicated that diffusion along with erosion could be the mechanism of drug release.