Efficacy and safety of metformin in the treatment of gestational diabetes: A protocol for systematic review and meta-analysis

BACKGROUND

The incidence of gestational diabetes is increasing, which not only cause adverse pregnancy outcomes, but also increases the risk of diabetes for pregnant women and their children. Insulin is the gold standard for the treatment of gestational diabetes, but there are some disadvantages, such as poor patient compliance. Metformin has been used in the treatment of gestational diabetes, but the evaluation of its efficacy and safety is lack of reliable evidence-based medicine evidence. The purpose of this study was to systematically investigate the efficacy and safety of metformin in the treatment of diabetic gestational diabetes.

METHODS

Computer searches China National Knowledge Infrastructure, Wanfang, Vipu Information Chinese Journal Service Platform and China Biomedical Database, PubMed, Embase, Web of Science, the Cochrane Library from the establishment of the database to November 2020, randomized controlled clinical trials of metformin in the treatment of gestational diabetes mellitus were conducted in English and Chinese. Two researchers independently carried out data extraction and literature quality evaluation on the quality of the included study, and the included literature was analyzed by Meta using RevMan5.3 software.

RESULTS

In this study, the efficacy and safety of metformin in the treatment of diabetic gestational diabetes were investigated by evaluating the outcome indicators of pregnant women and newborn babies respectively.

CONCLUSION

This study will provide reliable evidence for the clinical application of metformin in the treatment of diabetic gestational diabetes.

ETHICS AND DISSEMINATION

The private information from individuals will not be published. This systematic review also will not involve endangering participant rights. Ethical approval is not required. The results may be published in a peer-reviewed journal or disseminated in relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/ OSF.IO / 7RB95.

Pharmaceutical equivalent dissertation of Metformin hydrochloride brands

The aim of study is to establish pharmaceutical equivalence of different brands of Metformin tablets available in Karachi, Pakistan. The quality control parameters which are studied are weight variation test, hardness test, thickness, friability, disintegration and dissolution specified by BP/USP (British and United State Pharmacopoeia). Weight variation and hardness value requirement was complied by all brands. Disintegration time for all brands was within range i.e. 15 minutes and also complies with the BP/USP recommendation. All brands showed more than 90% drug release within forty five minutes. The present conclusion suggests that almost all the brands of Metformin that are available in Karachi meet the specification for quality control analysis. Assay performed by HPLC by keeping flow rate of 1.0 ml/min of the mobile phase and the quantitative evaluation at 225 nm was performed. The retention time of Metformin was found to be 2.5min. Method suitability for the quantitative determination of the drugs was proved by validation according to the International Conference on Harmonization (ICH) guidelines.

Fast and environmentally friendly quantitative analysis of active agents in anti-diabetic tablets by an alternative laser-induced breakdown spectroscopy (LIBS) method and comparison to a validated reversed-phase high-performance liquid chromatography (RP-HPLC) method

Laser-induced breakdown spectroscopy (LIBS) is evaluated as a potential analytic technique for rapid screening and quality control of anti-diabetic tablets. This paper proposes a simple LIBS-based method for the quantitative analysis of two active pharmaceutical ingredients (APIs): metformin (Met) and glybenclamide (Gly). In order to quantify both APIs, chlorine (Cl) concentration was estimated by employing the Cl/Br optical emission ratio, where Br was introduced as internal standard. Calibration curves were prepared, achieving linearity higher than 99%. On the other hand, for comparison to the proposed method, an isocratic reversed-phase high-performance liquid chromatography (RP-HPLC) method was also developed for quantitative determination of the same analytes by ultraviolet (UV) detection. The chromatographic separation was achieved on a Phenomenex Hypersil C18, 250 mm × 4.6 mm, 5 μm column. The mobile phase was K(2)HPO(4)/H(3)PO(4)-CH(3)OH and flow rate was 1.0 mL min(-1). The method is linear over a range of 10-60 μg mL(-1) for Gly and 5-30 μg mL(-1) for Met and the correlation coefficients were ≥0.99. Recoveries were found to be in the range of 95-101%. Furthermore, four different commercial brands of each active agent were evaluated by both proposed LIBS and chromatographic methods and results were compared with each other. The comparison was satisfactorily validated by analysis of variance (ANOVA).

Determination of metformin hydrochloride and glyburide in an antihyperglycemic binary mixture using high-performance liquid chromatographic-UV and spectrometric methods

Three methods were developed for simultaneous determination of metformin hydrochloride and glyburide in an antihyperglycemic binary mixture without previous separation. In the first method, a reversed-phase HPLC column with acetonitrile-water (60 + 40, v/v) mobile phase at 0.9 mL/min flow rate was used to separate both compounds, with UV detection at 254 nm. Linearity was obtained in the concentration range of 0.06--0.24 microg/mL for glyburide and 1.5-6.0 microg/mL for metformin hydrochloride. The second method depended on first- and second-derivative UV spectrometry with zero-crossing measurements. The first-derivative amplitude at 261 nm was selected for the assay of glyburide, and the second-derivative amplitude at 235 nm was selected for the assay of metformin hydrochloride. The third method depended on measuring the first derivative of the ratio-spectra at 241 nm for glyburide and 227 nm for metformin hydrochloride. For the second and third methods, Beer's law was obeyed in the range of 10-55 microg/mL for glyburide and 20-200 microg/mL for metformin. The proposed methods were extensively validated and applied for the analysis of some pharmaceutical formulations containing binary mixtures of the mentioned drugs.

Determination of metformin in human plasma by high-performance liquid chromatography

A simple, selective and sensitive high-performance liquid chromatographic method with spectrophotometric detection was developed for the determination of antihyperglycemic agent metformin in human plasma using a novel sample extraction procedure. Liquid-liquid extraction of metformin and ranitidine (as internal standard) from plasma samples was performed with 1-butanol/n-hexane (50:50, v/v) in alkaline condition followed by back-extraction into diluted acetic acid. Chromatography was carried out using a silica column (250 mmx4.6 mm, 5 microm) under isocratic elution with acetonitrile-40 mM aqueous sodium dihydrogen phosphate (25:75, v/v), pH 6. The limit of quantification (LOQ) was 15.6 ng/ml and the calibration curves were linear up to 2000 ng/ml. The mean absolute recoveries for metformin and internal standard using the present extraction procedure were 98 and 95%, respectively. The intra- and inter-day coefficient of variation and percent error values of the assay method were all less than 8.3%.

Bioequivalence studies with metformin: comparability of reference tablets from different origins

BACKGROUND

The choice of an appropriate reference product is still a problem within the European Union. When no direct comparisons between originator products in different countries are available, registration authorities are sometimes only prepared to grant registration for a generic product on the basis of a comparison with the originator product in the respective country. The aim of the investigation was therefore to evaluate the bioequivalence of reference products from different origins in two different bioequivalence trials with the same test drug.

METHODS

Two separate bioequivalence trials were performed involving the oral administration of one test and two reference products containing 500 mg metformin. Both studies had a randomized, open, single-dose, three-period crossover design and were carried out in 24 healthy volunteers. The reference products in the first trial were Glucophage mite (Germany) and Diabex (Australia). In the second trial the reference drugs were Glucophage mite (France) and Glucophage mite (Switzerland). The results of each trial were analyzed regarding the bioequivalence of the respective reference drugs.

FINDINGS

The reference drugs in each of both trials were bioequivalent: the 90% confidence intervals for both AUC(0-tlast) and C(max) were entirely within the acceptance range for bio-equivalence trials (0.80 - 1.25 for both parameters).

INTERPRETATION

In the case of metformin, the reference products available in the countries examined were very similar. This retrospective analysis involving two studies, therefore, confirmed bioequivalence between these reference products.