Simultaneous Determination Of Metformin Hydrochloride Research Articles

Stability Indicating RP-HPLC Method Development and Validation for Simultaneous Estimation of Metformin Hydrochloride and Remogliflozin Etabonate in Bulk and Tablet Formulation

A simple efficient stability-indicating validated RP-HPLC method has been developed for the simultaneous determination of Metformin hydrochloride (MET) and Remogliflozin etabonate (REM) in bulk and was applied to marketed formulations. The mobile phase used for detection was Phosphate Buffer (pH 4.0): Acetonitrile (60:40%v/v). Drug peaks were detected by a UV detector at 226nm. The linearity of the developed method was found to be 20-60µg/mL for Metformin hydrochloride and 4-12μg/mL for Remogliflozin etabonate. The Limit of Detection (LOD.) and Limit of Quantitation (LOQ.) were found to be 0.085µg/mL and 0.258µg/mL for MET and 0.010µg/mL and 0.030µg/mL for REM respectively. Hydrolysis by HCl, NaOH, hydrogen peroxide, UV light and temperature were performed on a formulation which proves that the proposed method was specific and will be suitable for routine quality control analysis.

Deduction of the operable design space of RP-HPLC technique for the simultaneous estimation of metformin, pioglitazone, and glimepiride

A reversed-phase RP-HPLC method was developed for the simultaneous determination of metformin hydrochloride (MET), pioglitazone (PIO), and glimepiride (GLM) in their combined dosage forms and spiked human plasma. Quality risk management principles for determining the critical method parameters (CMPs) and fractional factorial design were made to screen CMPs and subsequently, the Box–Behnken design was employed. The analytical Quality by Design (AQbD) paradigm was used to establish the method operable design region (MODR) for the developed method depended on understanding the quality target product profile (QTPP), analytical target profile (ATP), and risk assessment for different factors that affect the method performance to develop an accurate, precise, cost-effective, and environmentally benign method. The separation was carried out using a mobile phase composed of methanol: 0.05 M potassium dihydrogen phosphate buffer pH 3.7 with 0.05% TEA (78:22, v/v). The flow rate was 1.2 mL/min. DAD detector was set at 227 nm. Linagliptin (LIN) was used as an internal standard. The proposed method was validated according to The International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH). The assay results obtained by using the developed method were statistically compared to those obtained by the reported HPLC method, and a satisfying agreement was observed.

Analytical quality by design based on design space in reversed-phase-high performance liquid chromatography analysis for simultaneous estimation of metformin, linagliptin and empagliflozin.

Employing the Quality by Design paradigm through this work helped conclude the method operable design region for optimizing the high performance liquid chromatography (HPLC) assay using Design of Experiments and response surface methodology to obtain a good resolution and determination of all analysed compounds and to achieve a suitable analysis time. A deep understanding of the quality target product profile, analytical target profile and risk assessment for parameters that affect the method performance led to developing an accurate, precise and cost-effective method. Quality risk management principles were applied for determining the critical method parameters affecting the simultaneous determination of metformin hydrochloride (MET), linagliptin (LIN) and empagliflozin (EMP) by reversed-phase HPLC . The ternary mixture was successfully resolved in 5 min with a linearity range of (0.1–600) µg ml−1 for MET and (0.05–50) µg ml−1 for LIN and EMP. The newly developed method was validated according to the International Council for Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use guidelines. Good agreement was observed with the assay results of the reported UPLC one. To evaluate the greenness of the proposed method, an analytical Eco-Scale method was used.

STABILITY INDICATING HPLC METHOD DEVELOPMENT AND VALIDATION FOR THE SIMULTANEOUS ESTIMATION OF METFORMIN HYDROCHLORIDE AND DAPAGLIFLOZIN IN API AND PHARMACEUTICAL DOSAGE FORM

A simple and specific stability indicating reversed-phase high-performance liquid chromatography technique has been developed and validated for the concurrent estimation of metformin hydrochloride and dapagliflozin in bulk and pharmaceutical dosage form. The ideal conditions were established for the study or analysis of the drug such as chromatographic separation was carried out on THERMO fisher ODS C18 column containing mobile phase of water and acetonitrile 65:35 % v/v of pH 6.8 adjusted with 0.1 % ortho phosphoric acid at a flow rate of 1 ml/minutes detected wavelength at 240 nm. The retention time was found to be 2.13 minutes and 5.41 minutes for metformin hydrochloride (MET) and dapagliflozin (DAPA) respectively. The proposed method was found to be linear in the concentration range of 100-600 ug/ml for MET (R2=0.9999) and 1-6 ug/ml for DAP (R2=0.9996), respectively. Method was validated according to ICH guidelines. Co-relation coefficients for both the drugs were found to be less than one. The mean % recoveries obtained were found to be 99.06-100.32% for metformin and 99.1-100.18% for dapagliflozin respectively. Stress testing is carried out for both drugs in acid, base, peroxide, photolytic and thermal degradation. The developed method can be effectively applied for routine analysis in simultaneous determination of metformin hydrochloride and dapagliflozin in bulk and combined tablet dosage form.

Box-Behnken Design Assisted Protein Precipitation Optimization for Simultaneous Determination of Metformin Hydrochloride and Alogliptin Benzoate in Plasma along with Pharmacokinetic Application

The study focuses on systematic quality by design oriented approach for the optimization of a sensitive reverse phase liquid chromatographic bioanalytical method for determination of metformin hydrochloride and alogliptin benzoate in plasma along with its validation. Chromatographic separation was carried out on C18 column using gradient mode with mobile phase; 1-octane sulphonic acid (10 mM), acetonitrile and phosphate buffer pH 4, adjusted by orthophosphoric acid, at 1.0 ml/min using 235 nm as detection wavelength. A Box–Behnken design was applied to protein precipitation sample extraction method with centrifugation speed, centrifugation time and volume of plasma as the critical method parameters for maximizing percentage extraction recovery of metformin hydrochloride and alogliptin benzoate as the critical analytical attributes. The optimized condition for centrifugation speed, centrifugation time and volume of plasma considered as the critical method parameters for maximizing extraction recovery were 11 800 rpm, 15 min, 100 μl. This optimized extraction method gave clear samples and resulted in good correlation in the concentration range of 0.022-2.2 and 0.0012-0.12 μg/ml for metformin hydrochloride and alogliptin benzoate, respectively. The mean percentage extraction recoveries at three quality control levels were 90.83-95.87 % for metformin hydrochloride and 94.03-96.73 % for alogliptin benzoate. The plasma concentration time profile showed higher peak plasma concentration for formulation compared to pure drugs indicating that absorption of metformin and alogliptin hydrochloride from formulation was better. The developed liquid chromatographic method presented good quantitative capability, good linearity, higher extraction recovery, simpler operation and short analysis time with low cost.

Stability-indicating RP-HPLC method for simultaneous determination of metformin hydrochloride and vildagliptin in tablet and biological samples

The present work aimed to develop and validate a simple, rapid, sensitive, accurate, and precise method for simultaneous determination of metformin hydrochloride and vildagliptin in tablet and biological samples. Isocratic elution of both the analytes was performed at 35 °C by injecting 20 μL into Thermo Hypersil ODS C18 column (5 μm, 4.6 mm× 250 mm), while the flow rate was set to 0.8 mL/min. The mobile phase comprised of methanol, acetonitrile, and phosphate buffer (5:30:65, v/v, pH 3.5), and wavelength was selected at 212 nm. The overall run time per sample was 7.0 min with a retention time of 3.36 and 5.41 min for metformin hydrochloride and vildagliptin, respectively. The calibration curve was linear from 10–140 μg/mL for metformin and 1–14 μg/mL for vildagliptin with a coefficient of determination (R2) ≤ 0.9919, while repeatability and reproducibility (expressed as relative standard deviation) were lower than 1.13 and 0.97%, respectively. Force degradation studies indicated a complete separation of the analytes in the presence of their degradation products providing a high degree of method specificity. The proposed reversed-phase high-performance liquid chromatography (RP-HPLC) method was demonstrated to be simple and rapid for the determination of metformin hydrochloride and vildagliptin in commercially available tablet and biological samples providing recoveries ranged between 100.13–100.29%.

Stability-indicating capillary electrophoresis method for the simultaneous determination of metformin hydrochloride, saxagliptin hydrochloride, and dapagliflozin in pharmaceutical tablets

A capillary electrophoretic method coupled to a diode array detector (CE-DAD) was developed and validated for the simultaneous determination of metformin hydrochloride (MET), the dipeptidyl peptidase-4 (DPP-4) inhibitor saxagliptin hydrochloride (SAX), and the sodium glucose co-transporter (SGLT 2) inhibitor dapagliflozin (DAP). The proposed method was used for the determination of these drugs in binary antidiabetic combinations namely, SAX/MET, combination I, DAP/MET, combination II, and SAX/DAP, combination III. CE separation was performed on a fused silica capillary with background electrolyte consisting of 30 mM phosphate buffer (pH 6.0) with a high voltage of 30 kV, a pressure of 20 mbar, and an injection time of 40 s. The compounds were detected at 203 nm for SAX/DAP and 250 nm for MET. The method was linear in the concentration range of 10–200 µ g/mL (SAX), 1.25–50 µ g/mL (DAP), and 7.5–1000 µ g/mL (MET). Full validation of the proposed method was performed as per the ICH guidelines. The obtained errors and deviation values did not exceed 2% assessing good accuracy and precision, respectively. The stability-indicating potential of the proposed method was proved under different stress-degradation conditions. The proposed method was successfully applied to the analysis of the three binary combinations in their tablets.

Experimental design methodology for optimization and robustness determination in ion pair RP-HPLC method development: Application for the simultaneous determination of metformin hydrochloride, alogliptin benzoate and repaglinide in tablets

Experimental design methodology (DOE) surpasses traditional (one variable at a time) approach in improving the chromatographic separation performance with minimum effort and resources. Since combination therapy of oral hypoglycemic drugs was generally recommended by Clinical Practice Guidelines on hypoglycemic agent therapy for treatment of type 2 diabetes mellitus, DOE was adopted in development of an ion pair RP-HPLC method for the simultaneous determination of metformin hydrochloride (MET), alogliptin benzoate (ALO) and repaglinide (REP) in combined binary tablets. Screening using Plackett-Burman design followed by face centered composite design enabled the estimation of optimum settings that accomplish the most appropriate resolution and adequate peak shape within suitable run time. The designed models were statistically analyzed, graphically presented by surface plots and the relationships between coefficients of the derived polynomial equations were interpreted. The models fitted data adequately and could be used for response prediction. Chromatographic separation was achieved using Inertsil ODS column (250 mm, 4.6 mm, 5 μm), acetonitrile: phosphate buffer (0.01 M, adjusted to pH 2.5 with o-phosphoric acid): 0.3% sodium heptane sulfonate in water (60:20:20, v/v/v) as a mobile phase at flow rate 1 mL min−1. UV detection was carried out at 220 nm. Sharp and well separated peaks for the cited drugs were obtained. Laboratory prepared mixtures containing MET, ALO and REP were analyzed with mean percentage recoveries 99.66 ± 0.468, 99.98 ± 0.398 and 99.70 ± 0.988, respectively. The method was successfully applied for the determination of the drugs in binary tablets with good recoveries of 99.75 ± 0.6 and 99.74 ± 0.982 for MET and ALO tablets and 99.76 ± 0.619 and 100.08 ± 1.159 for MET and REP tablets. Method validation was performed according to ICH guidelines Q2 (R1). Robustness was evaluated using the created models. The greenness profile of the developed method was evaluated using the analytical Eco-scale and Green Analytical Procedure Index as assessment tools. The developed method proved to be accurate, selective, precise and ecofriendly procedure for the determination of the cited drugs in binary tablets and could be applied in quality control laboratories for routine analysis of the drugs.

Development and Validation of Stability-Indicating RP-HPLC Method for Simultaneous Determination of Metformin HCl and Glimepiride in Fixed-Dose Combination.

A simple reversed-phase high-performance liquid chromatography method was developed and validated for simultaneous determination of Metformin hydrochloride (MET) and Glimepiride (GLM) in combination and estimation of their principal degradation products. The separation was achieved using JASCO Finepak SIL (250 mm × 4.6 mm i.d. 5 μm) at ambient temperature. The optimized mobile phase composed of an aqueous phase (20 mM phosphate buffer, adjusted to pH 3.0) and an organic phase (methanol:acetonitrile; 62.5:37.5) in the ratio of 80:20. The flow rate was 1 mL/minute, and the analytes were detected at 230 nm. The developed method was validated for accuracy, precision, specificity, linearity, and sensitivity. The chromatographic analysis time was approximately six minutes with the complete resolution of MET (Rt = 2.75 minutes) and GLM (Rt = 5.87 minutes). The method exhibited good linearity over the range of 5–30 μg/mL for MET and 1–10 μg/mL for GLM. The drugs in combination were subjected to various stress degradation studies as per the International Conference Harmonization (ICH) guidelines. Results obtained from the stress degradation studies revealed that the developed method is applicable for stability studies.

Simultaneous Estimation of Metformin Hydrochloride, Glimepiride and Pioglitazone using First Generation Chemometric Methods

In this study, new feasible UV-Visible spectrophotometric and multivariate spectrophotometric methods were described for the simultaneous determination of Metformin hydrochloride (MET), Glimepiride (GLI) and Pioglitazone (PIO) in combined pharmaceutical tablets. Methanol is used as a solvent for analysis and whole UV region has been scanned from 200-400 nm. The resolution has been obtained by using multivariate methods as Classical least square (CLS), Inverse least squares (ILS), Principal Component Regression (PCR), Partial Least Squares Regression (PLSR) applied to the UV spectra of the mixture. The results obtained from all the methods were found within the limit.

Development and Validation of a Method for Simultaneous Determination of Metformin Hydrochloride and Sitagliptin Phosphate in a Formulation by RP-HPLC

Present study was aimed to develop and validate a reverse-phase high-performance liquid chromatography method for simultaneous determination of sitagliptin phosphate and metformin hy-drochloride in a marketed formulation. The drug separation was performed on Hibar-240, Li-chrosphere-100 C18 ODS (250 × 4.6 mm, 5 μm) column, at a flow rate of 1 mL/min. The mobile phase used was a mixture of methanol: potassium di-hydrogen phosphate buffer at a ratio of 70:30 v/v. The detection was carried out at a wavelength of 266 nm. The retention times of sitagliptin phosphate and metformin hydrochloride were found as 6.1 and 4.9 min respectively. Linear calibration curves with good correlation coefficients were obtained over the concentration ranges of 10 - 50 μg/mL for sitagliptin and 20 - 100 μg/mL for metformin. The limit of detection was 0.016 and 0.14 μg/mL and the limit of quantification was 0.048 and 0.42 μg/mL for sitagliptin phosphate and metformin hydrochloride respectively. Validation of the method demonstrated system selectivity, specificity, linearity, accuracy and precision. The developed method was found useful in the simultaneous analysis of sitagliptin phosphate and metformin hydrochloride in formulation.

Validated Hptlc Method For Simultaneous Determination Of Metformin Hydrochloride And Glibenclamide In Combined Dosage Form

This paper describes a simple, accurate and precise HPTLC method for simultaneous determination of Metformin Hydrochloride and Glibenclamide in a bulk as well as in the combined dosages form. During optimization of Mobile phases different solvents viz. butanol, methanol and triethylamine were tried. However resolution between metformin hydrochloride and Glibenclamide was not proper. A mobile phase of Methanol: Water: 0.4 % sodium sulphate in water (7: 5:11) was developed for the densitometric determination of the drug products. Aluminum plate coated with the silica Gel 60 F254 was used as stationary phase. UV spectra were taken in the range of 190 nm to 400 nm. Densitometric evaluation of the separated bands of Metformin hydrochloride and Glibenclamide was performed at 232 nm and at 238 nm respectively. The Rf values of Metformin hydrochloride and Glibenclamide were 0.27 and 0.80 respectively. Developed method was Linear over the range of 250 ng to 1750 ng/spot and 250 ng to 1750 ng /spot of Metformin hydrochloride and Glibenclamide respectively. Precision of the method was evaluated by calculating RSD for peak response by inerday and intraday analysis. Results were Interday RSD of peak response=1.52 % and Intraday RSD of peak response=1.90 % for Metformin hydrochloride. Similarly for Glibenclamide interday RSD of peak response=1.67% and Intraday RSD of peak response = 0.92 %. Accuracy was determined in terms of percentage recovery at three concentration levels for Metformin hydrochloride and for Glibenclamide. The results for metformin hydrochloride at three concentration levels are 95.79%, 97.84 % and 96.06 %. In case of Glibenclamide the results are 96.0 %, 97.03 % and 96.53 %. Specificity was proved by spectral analysis of Metformin hydrochloride and Glibenclamide. There was no any interference of methanol being used as a diluents and mobile phase at the Rf values of Metformin hydrochloride and Glibenclamide. Standard spectrum and sample spectrum of Metformin hydrochloride and Glibenclamide were overlain to confirm Rf values. ICH

Concurrent determination of Metformin and some ACE inhibitors: Its application to Pharmacokinetics

This study illustrates development and validation of a simple high performance liquid chromatographic method for the simultaneous determination of metformin hydrochloride and angiotensin-converting enzyme inhibitors (captopril, lisinopril, and enalapril) in bulk dosage form and their application in pharmacokinetic studies. The quality resolute chromatogram was obtained by using a Purospher® Star RP-18 endcapped (250×4.6mm id) column as stationary phase while acetonitrile-water 50:50 (v/v) as mobile phase, adjusted to pH 3.0 with phosphoric acid. Effluent was monitored at a flow rate of 1mLmin−1 at room temperature (25°C), detector was set at 218nm. The method was validated according to ICH guidelines. The linearity was studied over the concentration range of 10–10,000ngmL−1 for metformin and 30–10,000ngmL−1 for captopril, lisinopril, and enalapril, demonstrating good linearity with minimum r=0.9964, respectively. The developed method was successfully applied to pharmacokinetic studies of metformin, lisinopril, captopril and enalapril.

Development of Validated Stability Indicating Assay Method for Simultaneous Estimation of Metformin Hydrochloride and Vildagliptin by RP-HPLC

A simple, precise and stability-indicating HPLC method was developed and validated for the simultaneous determination of metformin hydrochloride (MET) and vildagliptin (VLG) in pharmaceutical dosage forms. The method involves use of easily available inexpensive laboratory reagents. The separation was achieved on Grace Cyano column (250 mm×4.6 mm) 5 µm with isocratic flow. The mobile phase was pumped at a flow rate of 1.0 mL/min, consisted of 25 mM ammonium bicarbonate buffer and acetonitrile (65:35, v/v). The UV detection was carried out at 207 nm. A linear response was observed over the concentration range of 25-125 µg/mL for MET and 50-250 µg/mL for VLG respectively. Limit of detection and limit of quantification for MET were 0.36 µg/mL and 1.22 µg/mL, and for VLG were 0.75 µg/mL and 2.51 µg/mL respectively. The method was successfully validated in accordance to ICH guidelines acceptance criteria for specificity, linearity, accuracy, precision, robustness, and system suitability. Individual drugs (MET and VLG) were exposed to thermal, photolytic, hydrolytic and oxidative stress conditions. The resultant stressed samples were analyzed by the proposed method. The method gave high resolution among the degradation products and the analytes. The peak purity of analyte peak in the stressed samples was confirmed by photo diode array detector. The proposed method was successfully applied for the quantitative analysis of MET and VLG in tablet dosage form, which will help to improve quality control and contribute to stability studies of pharmaceutical tablets containing these drugs.

Stability-Indicating RP-HPLC Method for Simultaneous Determination of Metformin Hydrochloride and Sitagliptin Phosphate in Dosage Forms

A new stability-indicating high-performance liquid chromatographic method has been developed for simultaneous analysis of metformin hydrochloride (MET) and sitagliptin phosphate (SIT) in pharmaceutical dosage forms. Chromatographic separation was achieved on a C8 column. The mobile phase was methanol–water 45:55 % (v/v) containing 0.2 % (w/v) n-heptanesulfonic acid and 0.2 % (v/v) triethylamine; the pH was adjusted to 3.0 with orthophosphoric acid. The flow rate was 1 mL min−1 and the photodiode-array detection wavelength was 267 nm. The linear regression coefficients for metformin and sitagliptin were 0.9998 and 0.9996 in the concentration ranges 50–450, and 10–150 μg mL−1, respectively. The relative standard deviations for intra and inter-day precision were below 1.5 %. The drugs were subjected to a variety of stress conditions—acidic and basic hydrolysis, and oxidative, photolytic, neutral, and thermal degradation. The products obtained from photolytic degradation were similar to those from neutral hydrolytic degradation and different from produced by acidic and basic hydrolysis. The method resulted in detection of 15 degradation products (D1–D15); among these, the structures of D1, D3, D9, and D13 were identified. The respective mass balance for MET and SIT was found to be close to 97.60 and 99.12 %. The specificity of the method is suitable for a stability-indicating assay.

Multivariate chemometric assisted analysis of metformin hydrochloride, gliclazide and pioglitazone hydrochloride in bulk drug and dosage forms.

In this work a numerical method, based on the use of spectrophotometric data coupled to partial least squares (PLS) regression and net analyte preprocessing combined with classical least square (NAP/CLS) multivariate calibration, is reported for the simultaneous determination of metformin hydrochloride (MET), gliclazide (GLZ) and pioglitazone hydrochloride (PIO) in synthetic samples and combined commercial tablets. Spectra of MET, GLZ and PIO were recorded at concentrations within their linear ranges (5-25 µg/ml, 0.5-8 µg/ml and 0.5-3 µg/ml respectively) and were used to compute a total of 25 synthetic mixtures involving 15 calibration and 10 validation sets between wavelength range of 200 and 400 nm in 0.1N HCl. The suitability of the models was decided on the basis of root mean square error (RMSE) values of calibration and validation data. The analytical performances of these chemometric methods were characterized by relative prediction errors and recovery studies (%) and were compared with each other. These two methods were successfully applied to pharmaceutical formulation, tablet, with no interference with excipients as indicated by the recovery study results. Mean recoveries of the commercial formulation set together with the figures of merit (calibration sensitivity, selectivity, limit of detection, limit of quantification etc.) were estimated. The proposed methods are simple, rapid and can be easily used as an alternative analysis tool in the quality control of drugs and formulation.

A Simple and Sensitive HPTLC Method for Simultaneous Determination of Metformin Hydrochloride and Sitagliptin Phosphate in Tablet Dosage Form

A simple, rapid, and precise high‐performance thin‐layer chromatographic (HPTLC) method for simultaneous estimation of two antidiabetic drugs, metformin hydrochloride and sitagliptin phosphate, in tablet dosage form has been developed and validated. Chromatography was performed on silica gel 60 F254 plates with butanol : water : glacial acetic acid (6 : 2 : 2, v/v/v) as mobile phase. This system gave a good resolution for metformin hydrochloride (Rf value of 0.35 ± 0.01) and sitagliptin phosphate (Rf value of 0.75 ± 0.01). Detection and quantification were carried out at 227 nm. The linear regression data for the calibration plot showed a good relationship with r = 0.9995 and 0.9991 for metformin hydrochloride and sitagliptin phosphate, respectively. The method was validated for precision and recovery. The limits of detection and quantification were 13.05 and 39.56 ng/μL for metformin hydrochloride and 2.65 and 8.03 ng/μL for sitagliptin phosphate, respectively. The amounts of the drugs in the marketed formulation were 99.86% and 98.91% for metformin hydrochloride and sitagliptin phosphate, respectively.

SIMULTANEOUS ESTIMATION OF METFORMIN HYDROCHLORIDE AND REPAGLINIDE BY HPLC METHOD

A reverse phase high performance liquid chromatographic method is developed for the simultaneous determination of metformin hydrochloride and repaglinide. Chromatography was carried out at ambient temperature and separation of these drugs was achieved on neosphere C18 column (150 x 4.6 mm i.d, 3.5 mcgm) as stationary phase with a mobile phase comprising of methanol: 0.05 M acetate buffer (pH 3.5) in ratio of (80:20 V/V) at flow rate 0.8 mL/min. The detection wavelength for metformin hydrochloride and repaglinide was 242 nm. The retention times for metformin hydrochloride and repaglinide were 1.8 0.2 min and 8.9 0.2 min respectively. The linearity of metformin hydrochloride and repaglinide was in the range of 2-10 mcg/mL and 5-25 mcg/mL respectively. The recovery was calculated by standard addition method. The proposed method was found to be suitable for simultaneous determination of metformin hydrochloride and repaglinide.

UV-Spectrophotometric-Assisted Chemometric Methods for the Simultaneous Determination of Metformin Hydrochloride and Gliclazide in Pharmaceutical Formulations

In this study, the simultaneous determination of Metformin hydrochloride (MET) and Gliclazide (GLZ) in pharmaceuticals by chemometric approaches using UV spectrophotometry has been reported. Spectra of MET and GLZ were recorded at several concentrations within their linear ranges between wavelengths of 200 nm to 400 nm in pH 6.8 phosphate buffer. Partial Least Squares regression (PLS) and Net Aanalyte Preprocessing combined with Classical Least Square (NAP/CLS) were used for chemometric analysis of data and the parameters of the chemometric procedures were optimized. The recoveries were satisfactory and statistically comparable. The method was successfully applied to pharmaceutical formulation, tablet, with no interference with excipients as indicated by the recovery study results. The proposed methods are simple, rapid and can be easily used in the quality control of drugs as alternative analysis tools.

Simultaneous Spectrophotometric Determination of Metformin Hydrochloride and Glibenclamide in Binary Mixtures Using Combined Discrete and Continuous Wavelet Transforms

In this work, a combined discrete and continuous wavelet transform analysis was developed for simultaneous spectrophotometric determinations of metformin hydrochloride and glibenclamide, two antidiabetic drugs, in binary mixtures without any chemical pretreatment. Absorption spectra were subjected to the 4-level db4 discrete wavelet transform (DWT) for signal de-noising. Selected continuous wavelet transform (CWT) families (rbio3.1 with scaling factor, a = 80, and gaus2, a = 60) were applied on these de-noised signals. Finally, a zero-crossing technique was used for the construction of calibration curves for both drugs. The proposed method was validated by analyzing synthetic mixtures of the investigated drugs with various concentrations. The amount of metformin hydrochloride and glibenclamide were determined by using CWT amplitudes in zero-crossing points. The mean recovery values of metformin hydrochloride and glibenclamide were found between 98.6-102.0 and 97.9-102.4% for rbio3 and 98.3-101.2 and 97.1-101.4% for gaus2 families, respectively. The obtained results showed that the developed method is a simple, rapid and precise procedure for the simultaneous determination of metformin hydrochloride and glibenclamide in binary mixtures.