A study on the interaction between metformin and constituents of a commercial herbal product

Purpose: To investigate the interactions between metformin and Yoyo Bitters® including some of its constituents in the management of diabetes mellitus.Method: Using the generic form of metformin (Glucophage®) tablets, tests such as disintegration time, dissolution profile, Fourier transform infrared (FTIR) spectroscopy and in vivo hypoglycaemia tests using Wistar albino rat were performed for metformin to investigate its behaviour in the presence and absence of Yoyo Bitters and some plant extracts used in its formulation.Results: Metformin tablets used met BP specification in terms of pharmaceutical properties. There was no significant change in the disintegration properties of the metformin tablets in the presence of Yoyo Bitters (p > 0.05) while a significant change occurred in the dissolution profile (p < 0.05). The FTIR spectra showed some level of interactions due to disappearance of some spectral peaks. In vivo result showed a significant reduction (p < 0.05) in the duration of action of metformin.Conclusion: Concomitant administration of metformin and Yoyo Bitters showed interaction that appeared antagonistic to the hypoglycaemic effect of metformin both in vitro and in rat modelsKeywords: Metformin, In vitro interactions, Yoyo Bitters, Diabete

The gelling properties of Dillenia indica mucilage in benzyl benzoate emulgel formulations

The objective of the study was to evaluate the gelling properties of Dillenia indica mucilage in benzyl benzoate emulgel formulation. Mucilage was extracted from the fruits of Dillenia indica using established methods and characterized by rheology and swelling. Emulsion (F1) was prepared using the continental emulsification method. Gelling agents (2 %w /v) were prepared by dispersing in distilled water with constant stirring at a moderate speed using a magnetic stirrer. F1 was added to the gel (0-75 %w /w) to obtain emulgel formulations and evaluated using viscosity, globule size, pH, release profiles and kinetic modeling. Data were expressed as mean ± SD, and similarity factor (f2) was used to compare all formulations. Formulation viscosity was significantly higher with carbopol than with Dillenia; globule sizes increased with concentration of gelling agents, and pH reduced as the concentration of Dillenia increased. All formulations showed controlled release properties with t80 ranging between 114 and 660 min. The release was governed by Korsmeyer-Peppas model. Formulation F5 prepared with 50 % Dillenia showed highest similarity to F4 prepared with 75 %w /w carbopol. Dillenia indica demonstrated acceptable gelling properties comparable with that of carbopol and could be improved for use in emulgel formulations