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

Development of Capillary Zone Electrophoresis Method for the Simultaneous Separation and Quantification of Metformin and Pioglitazone in Dosage Forms; and Comparison with HPLC Method

A capillary zone electrophoretic (CZE) method was developed, validated, and applied for the assay of metformin (MET) and pioglitazone (PIO) in pharmaceutical formulations. The optimum running buffer composition was found to be 75 mmol/L phosphate buffer containing 30% acetonitrile (ACN) at pH 4.0. The optimum instrumental conditions were found to be injection time, 10 s; applied voltage, 25 kV; hydrodynamic injection pressure, 0.5 psi for 10 s, capillary temperature, 25 °C; and the detection wavelength, 210 nm. The quantifications were calculated based on the ratio of the peak areas of analytes to atenolol as an internal standard. The CZE method was validated in terms of accuracy (98.21-104.81%), intra- and inter-day precision of migration time and peak area (relative standard deviation ≤ 5%), linearity (correlation coefficients ≥ 0.9985), limit of detection (≤0.277 μg/mL), and limit of quantitation (≤0.315 μg/mL). The proposed method was applied for the analysis of PIO and MET both individually and in a combined dosage tablet formulation. All electrophoretic parameters were calculated and evaluated. A previously reported high-performance liquid chromatographic (HPLC) method was also applied to the same samples. A comprehensive comparison was then carried out for the analytical features of both methods CZE and HPLC. Comparable results were obtained with the advantage of reagent consumption and separation efficiency of CZE over HPLC and shorter analysis time by HPLC compared with CZE.

Applications of capillary electrophoresis in the fields of environmental, pharmaceutical, clinical and food analysis (2019-2021)

So far, the potential of capillary electrophoresis (CE) in the application fields has been increasingly excavated due to the advantages of simple operation, short analysis time, high-resolution, less sample consumption and low cost. This review examines the implementations and advancements of CE in different application fields (environmental, pharmaceutical, clinical and food analysis) covering the literature from 2019 to 2021. In addition, ultrasmall sample injection volume (nanoliter range) and short optical path lead to relatively low concentration sensitivity of the most frequently used UV-absorption spectrophotometric detection, so the pretreatment technology being developed has been gradually utilized to overcome this problem. Despite the review is focused on the development of CE in the fields of environmental, pharmaceutical, clinical and food analysis, the new sample pretreatment techniques of microextraction and enrichment which fit excellently to CE in recent three years are also described briefly. This article is protected by copyright. All rights reserved.

Simple TLC-spectrodensitometric method for studying lipophilicity and quantitative analysis of hypoglycemic drugs in their binary mixture

A selective and simple salting-out-assisted thin-layer chromatographic methodology was developed for the simultaneous determination of two oral hypoglycemic drugs, dapagliflozin (DAPA) and metformin (MET) in their pure forms, tablets and spiked human plasma samples. Silica gel 60 F₂₅₄ plates were used in the separation of the two drugs using a mobile phase consisting of 0.5 m (NH₄ )₂ SO₄ and methanol (3:7, v/v). The plates were scanned in the reflectance mode at λ_max  = 237 nm. The obtained retardation factor (R_f ) values for DAPA and MET were 0.77 ± 0.02 and 0.25 ± 0.02, respectively. The thin-layer chromatography method was validated according to International Conference on Harmonization guidelines. The peak areas were linearly increased with the increases in concentrations of 45-1,000 and 50-1,500 ng/band for DAPA and MET, respectively. Moreover, the method was applied to estimate the molecular lipophilicity parameters of DAPA and MET via retention data. The suggested method was efficiently utilized for the analysis of DAPA and MET in pharmaceutical tablets and plasma samples with recoveries 98.4-100.4 and RSDs in the ranges of 1.4-2.6 and 2.2-3.0% for DAPA and MET, respectively.

Choices of chromatographic methods as stability indicating assays for pharmaceutical products: A review

Stability indicating assay describes a technique which is used to analyse the stability of drug substance or active pharmaceutical ingredient (API) in bulk drug and pharmaceutical products. Stability indicating assay must be properly validated as per ICH guidelines. The important components in a stability indicating assay include sensitivity, specificity, accuracy, reliability, reproducibility and robustness. A validated assay is able to measure the concentration changes of drug substance/API with time and make reliable estimation of the quantity of the degradation impurities. The drug substance is separated and resolved from the impurities. Pros and cons of HPLC, GC, HPTLC, CE and SFC were discussed and reviewed. Stability indicating assay may consist of the combination of chromatographic separation and spectroscopic detection techniques. Hyphenated system could demonstrate parallel quantitative and qualitative analysis of drug substances and impurities. Examples are HPLC-DAD, HPLC-FL, GC-MS, LC-MS and LC-NMR. The analytes in the samples are separated in the chromatography while the impurities are chemically characterised by the spectroscopy in the system. In this review, various chromatographic methods which had been employed as stability indicating assays for drug substance and pharmaceutical formulation were systematically reviewed, and the application of hyphenated techniques in impurities characterisation and identification were also discussed with supporting literatures.

Application of two charge transfer complex formation reactions for selective determination of metformin hydrochloride in pharmaceuticals and urine

Background

Metformin hydrochloride (MFH) is a biguanide class anti-diabetic drug used to treat type-2 diabetes mellitus. Its reaction with two charge-transfer complexing agents, p-chloranilic acid (PCA) and 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) in acetonitrile medium to yield coloured products measurable at wavelengths of maxima 530.0 and 460.0 nm, respectively, was conveniently used to develop two spectrophotometric methods for analyses of bulk sample and tablets.

Results

The effect of solvent, reagent concentration and reaction time to form charge-transfer (CT) complexes was meticulously studied and optimized. Under optimised conditions, the absorbance at the respective wavelength of maximum versus concentration of MFH was in linear correlation for the range from 8.0 to 320.0 and from 1.6 to 64.0 μg mL-1 in PCA and DDQ methods, respectively, and correspondingly, the values of molar absorptivity of 0.733 × 103 and 0.257 × 104 L mol-1 cm-1 and Sandell sensitivity of 0.3620 and 0.0644 μg cm-2. The quantification (QL) and detection (DL) limits were 2.67 and 0.88 μg mL-1 for PCA method, and 0.33 and 0.11 μg mL-1 for DDQ method.

Conclusion

The new methods were emerged as repeatable and reproducible, with replicate measurements for intra- and inter-day variations as showed by obtained RSD values of < 2%. Within a day and between day relative errors were ≤ 2.18%. Methods were also validated for robustness, ruggedness and selectivity and agreeing results were produced. The methods were used to analyse MFH-containing tablets very accurately and precisely as reflected by the mean recovery value close to 100% and lower RSD values, respectively. Analysis of spiked human urine yielded excellent mean recoveries, indicating the absence of interference from endogenous substances.

Fluorescence spectroscopy for determination of dapagliflozin in pure form and its tablets formulation; Application to content uniformity testing

A new, valid method was developed for quantitative spectrofluorimetric analysis of dapagliflozin (DGF) in its pure form and its commercially available tablets (Farxiga®). The proposed analytical method based on measurement of fluorescence intensity for DGF at 303 nm after excitation at 278 nm. Various experimental parameters influencing the fluorescence of DGF were examined to produce the optimal conditions. DGF was successively assayed in concentration range of (100-1000 ng mL^-1) with lower detection limit (LOD) of 26.49 and quantitation limit (LOQ) was 79.48 ng mL^-1. The suggested method was validated according to ICH guidelines for the estimation of DGF in its pure form and its new dosage form with percent recovery of 100.43 ± 1.15. The proposed method was adapted to examine DGF in content uniformity testing according to United States Pharmacopeia guidelines. This method can be used in routine analysis of DGF in quality control lab.

Capillary electrophoretic methods for quality control analyses of pharmaceuticals: A review

Capillary electrophoresis represents a promising technique in the field of pharmaceutical analysis. The presented review provides a summary of capillary electrophoretic methods suitable for routine quality control analyses of small molecule drugs published since 2015. In total, more than 80 discussed methods are sorted into three main sections according to the applied electroseparation modes (capillary zone electrophoresis, electrokinetic chromatography, and micellar, microemulsion, and liposome-electrokinetic chromatography) and further subsections according to the applied detection techniques (UV, capacitively coupled contactless conductivity detection, and mass spectrometry). Key parameters of the procedures are summarized in four concise tables. The presented applications cover analyses of active pharmaceutical ingredients and their related substances such as degradation products or enantiomeric impurities. The contribution of reported results to the current knowledge of separation science and general aspects of the practical applications of capillary electrophoretic methods are also discussed.

Pharmaceutical Analytical Profile for Novel SGL-2 Inhibitor: Dapagliflozin

Dapagliflozin (DPG) is a novel drug from class of sodium glucose co-transporter 2 (SGL-2) inhibitors which has been evolved as profound treatment option for the type-2diabetes mellitus (T2DM). Considering the severity of the disease the drug is of crucial significance for the therapy and associated research. As a pharmaceutical dosage form DPG has immense importance as an individual drug and with other antidiabetic drugs as combinations. The drugs existing in combination with DPG are Metformin (MET) and Saxagliptin (SXG). The existence of the Dapagliflozin in combinations further created more interest in reviewing its pharmaceutical, analytical and bio-analytical profile. Such estimations are always in need of precise pharmacological and physicochemical information; hence authors have presented it beforehand. Authors hereby wish to present an essential update pertaining to emergence of gliflozins and DPG. The article further presents a simultaneous and comparative assessment of the analytical investigations published in literature for pharmaceutical estimation to assist future analysis. The thorough literature searches revealed fifty three research papers in total till date. A comprehensive presentation of typical; hyphenated and unique methods used for analysis are outlined effectively. The percentile utilization of analytical approaches since appearance of first publication in 2010 is investigated to report trend in determination. The present review explores the pharmaceutical estimation of DPG to scientifically potentiate analytical research and therapeutic future of DPG as a novel SGL-2 Inhibitor antidiabetic.

TLC-spectrodensitometric method for simultaneous determination of dapagliflozin and rosuvastatin in rabbit plasma: stability indicating assay and kinetic studies

Herein, a sensitive and reliable eco-friendly TLC-spectrodensitometric method has been established for the simultaneous determination of dapagliflozin (DAPA) and rosuvastatin (ROSV) for the first time. TLC separation was carried out on silica gel F₂₅₄ using ethyl acetate : methanol (5 : 0.1, v/v) as a mobile phase and UV measurement at 243 nm. The method was fully validated according to ICH guidelines. Acceptable separation was achieved with R_f values of 0.23 and 0.44 for DAPA and ROSV, respectively. Regression plots revealed linear relationships in the concentration range 20–2500 ng per band and 10–2500 ng per band with LODs of 6.60 and 3.57 ng per band for both DAPA and ROSV, respectively. The relative standard deviations (RSDs%) were found to be 1.35 and 0.53 for DAPA and ROSV, respectively. Moreover, kinetic studies were conducted for measurement of degradation rate constant (k) and half life time (t_1/2) of DAPA and ROSV via forced photo-degradation.

Mixtures of DAPA and ROSV were separated using ethyl acetate : methanol (5 : 0.1 v/v) as mobile phase and applied in plasma and urine samples in addition to stability indicating and kinetic studies.

Capillary electrophoresis for the investigation of two novel aminoalkanol derivatives of 1,7-diethyl-8,9-diphenyl-4-azatricyclo[5.2.1.02,6] dec-8-ene-3,5,10-trione as potential anticancer drugs in water solution and serum

A simple, rapid, capillary zone electrophoresis method was developed and validated for the analysis of two novel aminoalkanol derivatives (I) and (II) of 1,7-diethyl-8,9-diphenyl-4-azatricyclo[5.2.1.0^2,6 ]dec-8-ene-3,5,10-trione, which were found in earlier studies as potential anticancer drugs. Samples were analyzed to demonstrate the specificity and stability indicating ability of the developed method. The samples were extracted using n-hexane-ethyl acetate mixture in the ratio of 90:10. Electrophoretic separation was performed on a eCAP fused silica capillary (37 cm length, 50 µm inside diameter) with a 50 mM tetraborate buffer as a background electrolyte adjusted to pH = 2.5. The separation time of (I) and (II) was achieved within 7 min. In addition, analysis of the two compounds in the serum was conducted. Limits of detection of (I) and (II) by UV absorbance at 200 nm were achieved in the range of 87.4-92.1 ng/mL. The sufficient recovery was observed in the range of 90.3-99.8%. The quantification limits for the compounds (I) and (II) were in the range of 279.71-291.03 ng/mL, respectively. The method has been successfully applied to the analysis of compounds (I) and (II) in serum samples.