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Niosomes as drug delivery systems have the ability to decrease drugs' side effects and increase their therapeutic effectiveness. Metformin HCl is an oral antihyperglycemic agent belonging to biguanides. It is the most commonly chosen drug as a startup therapy for patients newly diagnosed with type 2 diabetes. This study aims to encapsulate metformin HCl inside niosomes to be used as a transdermal formulation helping to prolong its antidiabetic effect and investigate its ability to enhance wound healing in diabetic patients. Thin film hydration method was used to prepare metformin HCl niosomes using different proportions of Span 60, Span 40, Tween 80, and cholesterol. All formulations were characterized using transmission electron microscope, zeta potential, and vesicle size. In vitro release studies, stability studies and in vivo evaluation were conducted on selected niosomal formulations. The results of entrapment efficiency ranged from 13% to 32%. Vesicle sizes were determined in nano-range. The in vitro release profile of metformin HCl from niosomes occurred in two consecutive phases. Biological evaluation on diabetic rats revealed that metformin HCl niosomal gel given every 2 days showed a better sustained antidiabetic effect than oral doses given daily. It also showed an improvement in wound healing for diabetic rats given metformin formulations compared to nontreated ones. [ABSTRACT FROM AUTHOR]

The aim of this work was to improve the mechanical properties of Metformin HCl by its recrystallization in the presence of different polymers and excipients using a wide range of polarity solvents. The recrystallized drug in the presence of lactose anhydrous (lactose) was further studied for its topographical, micromeritic, mechanical, compressional, solubility, and dissolution properties. Lactose-treated crystals were bigger in size with equidimentional shape. Crystals showed improvement in flow and packability with rich drug content (96.17%). Heckel parameters indicated greater plastic deformation (K = 0.474) and tensile strength compared to the pure drug (K = 0.137). Pellets prepared from crystals showed negligible elastic recovery (1.06%) compared to the pure drug (5.73%). Differential scanning calorimetry showed no degradation or polymorphic transformation of the drug even after stability studies (40°C, 75% RH). Fourier transform infrared spectroscopy proved hydrogen bond generation between the drug and lactose with a stable nature. The amount of directly compressible diluents could be minimized in tablet formulation, which ultimately reduced the overall tablet mass. The study highlights an influence of lactose on morphology, leading to a modified performance of recrystallized Metformin HCl. [ABSTRACT FROM AUTHOR]

The aim of this work was to investigate the effect of ethanol on the in vitro swelling and release behaviors of Carbopol®-based tablets. The swelling behavior of drug-free compacts and the release of model drugs (metformin HCl, caffeine and theophylline) from matrix tablets were evaluated in acidic and buffered media with 0, 20 and 40% (v/v) ethanol. Release data were analyzed by fitting to Higuchi and Peppas models and calculation of similarity factor ( f2). ANOVA tests were performed to determine significant factors on swelling and release. It was found that ethanol affects swelling and erosion of drug-free Carbopol® compacts, and the effect was highly dependent on medium pH. For matrix tablets, no dose dumping due to ethanol was manifested. The release rate and mechanism, however, were significantly affected by ethanol concentration as indicated by ANOVA applied to the constant, KH, from Higuchi model and the exponent, n, from Peppas model, respectively. The effect of ethanol on release was further confirmed by similarity factor results, which indicated that ethanol led to different release profiles ( f2 < 50) in seven of eight cases for matrices containing metformin HCl and in three of eight cases for matrices containing caffeine and theophylline. [ABSTRACT FROM AUTHOR]

The goal of diabetes therapy today is to achieve and maintain as near normal glycemia as possible to prevent the long-term microvascular and macrovascular complications of an elevated blood glucose. A newly developed inlay osmotic pump tablet (IOPT) can deliver glipizide (GLZ) and metformin HCl (MET) gradually in controlled manner. The aim of present investigation was to prepare the IOPT that can deliver >75% of GLZ in 2 h, whereas MET released after 2 h and sustained up to 12 h. In the present work, HP-β-CD was used to modify the solubility of GLZ before incorporating in the osmotic system and MET was spray-dried with HPMC A15C to modify its release profile, flow property, and compressibility. Various parameters mainly G75% (75% GLZ release), tLMET (lag time of MET release from device), Q10 h (percent of MET released within 10 h), and RSQZERO ( R2 of release data fitted to zero-order equation) were used to compare different formulations. The effects of different formulation variables, that is, osmagents, concentration of hydrophilic polymer, diameter of drug releasing orifice, and coating composition on the drug release profile were investigated. The release rate of GLZ could be effectively modified by the addition of sodium carbonate and sodium chloride, whereas the release rate of MET was adjusted by dual-coating system and by addition of hydrophilic polymer. The developed inlay osmotic system could be effective in the multidrug therapy of diabetes by delivering both drugs in a controlled manner. [ABSTRACT FROM AUTHOR]

Simultaneous estimation of active ingredients in multicomponent pharmaceutical products normally requires the use of separation techniques, such as HPLC, HPTLC, or GC, followed by their quantitation. Presented here are two spectrophotometric methods that do not require prior separation for simultaneous estimation of three drugs—pioglitazone HCl, metformin HCl, and glibenclamid—in a tablet formulation. Shimadzu UV 1700, capable of multicomponent analysis, was used for quantitation. In method I, absorbance of the sample solution was measured at 285 nm and 300 nm for the estimation of pioglitazone HCl and glibenclaimide, and at 237 nm for estimation of metformin hydrochloride, respectively. Method II is based on a multiwavelength spectroscopic method. Recording the absorbances of standard solutions at 237 nm, 268 nm, 280 nm, and 300 nm were processed by means of statistical calculations and results of the sample solution were obtained. All three drugs obey Beer's law in the concentration ranges used for the methods. The result of the analysis for both methods were tested and validated for various parameters according to ICH guidelines. The utility of the developed methods has been demonstrated by an analysis of commercial formulation containing all the three drugs. [ABSTRACT FROM AUTHOR]

The emerging new fixed dose combination of metformin hydrocholride (HCl) as sustained release and glipizide as immediate release were formulated as a bilayer matrix tablet using hydroxy propyl methyl cellulose (HPMC) as the matrix-forming polymer, and the tablets were evaluated via in vitro studies. Three different grades of HPMC (HPMC K 4M, HPMC K 15M, and HPMC K 100M) were used. All tablet formulations yielded quality matrix preparations with satisfactory tableting properties. In vitro release studies were carried out at a phosphate buffer of pH 6.8 with 0.75% sodium lauryl sulphate w/v using the apparatus I (basket) as described in the United States Pharmacopeia (2000). The release kinetics of metformin were evaluated using the regression coefficient analysis. There was no significant difference in drug release for different viscosity grade of HPMC with the same concentration. Tablet thus formulated provided sustained release of metformin HCl over a period of 8 hours and glipizide as immediate release. [ABSTRACT FROM AUTHOR]

Hydrophilic matrices are widely used for extended release drug delivery, with hypromellose (HPMC) being a popular rate-controlling carrier. The FDA has recently issued an alert regarding the potential negative influence of alcohol on extended release dosage forms. The aim of this study was to investigate the hydroalcoholic solution effect on hydration, gel formation and drug release from HPMC matrices. None of the investigated matrix formulations (felodipine, gliclazide, and metformin hydrochloride) resulted in dose-dumping when exposed to ethanol solutions. HPMC compacts made of three different viscosity grades of Methocel showed consistent swelling and gel formation when exposed to hydroalcoholic media. [ABSTRACT FROM AUTHOR]