Ecofriendly appraisal of stability-indicating high-performance chromatographic assay of canagliflozin and metformin with their toxic impurities; in silico toxicity prediction.

Canagliflozin is an oral hypoglycemic drug recently formulated in combination with a biguanide, metformin hydrochloride, for improving its hypoglycemic action. Canagliflozin has one reported major degradation product, also metformin hydrochloride has one reported major degradation product, cyanoguanidine, and has a potential toxic impurity, melamine, that is reported to cause crystalluria that causes chronic kidney inflammation and nephrolithiasis leading to a renal failure. As per International Conference of Harmonization guidelines; a drug degradation product is classified as a type of drug impurities. Toxicity profiles of canagliflozin and metformin major degradation products were studied where in silico data disclosed toxicity too; the development of a specific chromatographic thin layer chromatographic assay was a must for quantification of such toxic related components along with the drugs in laboratory-prepared mixtures as a superior study. The proposed method was validated as per the International Conference of Harmonization and applied for the assay of Vokanamet tablets. The separation was achieved using acetone:ethyl acetate:acetic acid (8:2:0.2, by volume) as scanning eluted bands at 205 nm. For minimal environmental impact; greenness profile appraisal of the proposed assay was performed by three greenness assessment approaches; analytical Eco-Scale, Green Analytical Procedure Index, and Greenness metric approaches.

Fourier Transform Infrared Spectroscopic, Spectrofluorimetric Assays of Canagliflozin, and Stability-Indicating UV-Spectrophotometric Method for the Simultaneous Determination of Canagliflozin and Metformin.

BACKGROUND: Green Fourier transform infrared (FTIR) spectroscopy, using potassium bromide (KBr) disc technique, eliminates the consumption of hazardous chemicals. Spectrofluorimetry for drugs that have native fluorescence. Mean centering of ratio spectra (MCRS) analysing overlapped spectra without preliminary separation. OBJECTIVE: Three simple, accurate, and sensitive methods have been developed and validated for the determination of canagliflozin (CANA); one is a stability-indicating method for CANA and metformin (MET) determination. METHODS: Method A is FTIR using a KBr disc for CANA determination measuring alkyl halide C-F peak area centered on 1230/cm. Method B is spectrofluorimetry using Δ λ = 50 nm synchronous mode at a peak maximum of 291.8 nm for CANA determination using methanol as solvent. Method C is a stability-indicating MCRS method measuring the peak amplitude of CANA and MET at 306.2 and 246.6 nm, respectively, in their mixture with complete CANA oxidation degradation. RESULTS: The linear ranges were: FTIR spectroscopy, 1.50-24.70 µg/mg CANA; spectrofluorimetry, 100.00-600.00 ng/mL CANA; and MCRS, 1.00-25.00 µg/mL CANA and 1-30 µg/mL MET. CONCLUSION: All results were statistically compared with a reported method: no significant difference was observed. HIGHLIGHTS: The proposed methods can be used efficiently for routine analysis in QC laboratories. A green FTIR method utilizes only one reagent, KBr. Spectrofluorimetry using a constant wavelength synchronous scan of CANA native fluorescence in nanogram concentrations overcomes conventional excitation/emission spectra drawbacks and proves that the solvent effect in the fluorescence intensity differs according to concentration used. Stability-indicating MCRS determines the studied drugs in bulk, pharmaceutical formulations, accelerated and long-term stability study samples.

Application of experimental design in HPLC method optimization and robustness for the simultaneous determination of canagliflozin, empagliflozin, linagliptin, and metformin in tablet.

Gliflozins and gliptins represent two different pharmacological drug classes that exert different and potentially complementary glucose-lowering effect in patients with type II diabetes mellitus. A novel, selective, and sensitive HPLC method was developed for the determination of canagliflozin, empaglifozin, linagliptin, and metformin in pure form, in laboratory prepared mixtures, and in pharmaceutical dosage form. Experimental design optimization was applied by using Plackett-Burman and face-centered composite designs to achieve the best resolution with minimum experimental trials. Three significant variables affecting optimization, namely buffer pH, percentage of methanol, and percentage of acetonitrile, were studied. Chromatographic separation was achieved using an Agilent Eclipse C8 column, and column temperature was kept at 45°C. The mobile phase was composed of dipotassium hydrogen phosphate buffer (0.05 M, adjusted to pH 6 using o-phosphoric acid):acetonitrile:methanol (50:25:25, v/v/v) at a flow rate of 1.5 mL/min. Sharp and well-resolved peaks of the cited drugs were obtained. The method was fully validated in terms of linearity, accuracy, precision, selectivity and robustness in agreement with the International Council of Harmonization (ICH) guidelines Q2 (R1). Satisfactory results were obtained by the analysis of tablets through applying the developed method. Therefore, it could be performed for the analysis of the cited drugs in quality control laboratories.

Validated Liquid Chromatographic Method for the Determination of (Canagliflozin, Dapagliflozin or Empagliflozin) and Metformin in the Presence of (1-Cyanoguanidine).

A simple and accurate liquid chromatographic method has been developed and validated for the determination of either canagliflozin, dapagliflozin propandiol monohydrate or empagliflozin and metformin in presence of metformin major degradation product;1-cyanoguanidine. The Liquid Chromatographic (LC) method was based on isocratic elution on Prontosil (Lichrosorb 100-5-NH2) column using a mobile phase consisting of NaH2PO4 buffer (10 mM, pH 2.8):acetonitrile (18.5:81.5, v/v), at a flow rate of 2 mL/min-1. Quantitation was achieved with UV detection at 225 nm. The validation of the method was assessed according to International Conference on Harmonization (ICH) guidelines. Linearity, accuracy and precision were satisfactory over the concentration ranges of 12.5-100, 3.75-30, 0.3075-2.46, and 0.3125-2.5 µg/mL for metformin HCl, canagliflozin, dapagliflozin propandiol monohydrate and empagliflozin, respectively. Limits of detection and quantitation were found to be 0.068, 0.135, 0.077 and 0.069 µg/mL and 0.206, 0.410, 0.233 and 0.210 µg/mL for metformin HCl, canagliflozin, dapagliflozin propandiol monohydrate and empagliflozin, respectively. The developed method is suitable for the quality control and routine analysis of the cited drugs separately or in combinations.

Stability-indicating chromatographic and chemometric methods for environmentally benign determination of canagliflozin and its major degradation product; A comparative study and greenness assessment.

Recently, concepts of sustainable developments, like considering the environmental effect of chemicals used and the amount of hazardous wastes produced, has gained much interest. In this work, a recently approved treatment for type II diabetes mellitus, canagliflozin, was quantified along with its degradation product by two eco-friendly methods. The first was a specific green HPLC method using a C18 column as a stationary phase and a mobile phase consisting of methanol-water (98:2, v/v) pumped at a flow rate of 1 mL/min with UV detection at 225 nm, and using ibuprofen as an internal standard. The second method was a partial least square chemometric method with the wavelength range 220-320 nm and the data was autoscaled as a preprocessing step for determination of canagliflozin and its degradation product. The greenness profile of the developed methods was studied and compared with the reported methods. The proposed methods were suitable alternatives for the environmentally harmful reported methods for quality control analyses of canagliflozin-containing samples, analysis of pharmaceutical formulations and sensitive tracing of its possible degradation product. The methods were validated as per International Conference on Harmonization guidelines and statistically compared with the reported HPLC method.

Development and Validation of Spectrophotometric Methods for the Determination of Canagliflozin or Gliclazide and Metformin in the Presence of Metformin Impurity (1-Cyanoguanidine).

Background: Quantitative multicomponent analysis is considered an analytical goal to save time and cost in analysis. Objective: This work aimed to provide sensitive and selective [successive ratio subtraction coupled with constant multiplication (SRS-CM) and chemometric] methods for the determination of coformulated antidiabetic drugs, namely canagliflozine and metformin or gliclazide and metformin in presence of metformin degradation product, 1-cyanoguanidine. Methods: SRS-CM method was developed for the determination of canagliflozin and metformin at 292 and 237 nm, respectively, using 14 µg/mL canagliflozin as a divisor in the first step to cancel the spectrum of canagliflozin. Then, 18 µg/mL metformin was used as a divisor in the second step to cancel the spectrum of metformin. Finally, we obtained the spectrum of cyanoguanidine. Chemometric method was applied for the determination of the gliclazide and metformin mixture in a 225-235 nm range. Sample enrichment technique was used to increase the concentration of canagliflozin or gliclazide to allow its simultaneous determination with metformin without prior separation. Results: Validation parameters according to the International Conference on Harmonization guidelines were satisfactory over the concentration ranges of 5 to 16 µg/mL for canagliflozin and metformin as well as 2.5 to 12.5 and 6 to 24 µg/mL for gliclazide and metformin, respectively. Conclusions: The method provides sufficient selectivity and accuracy to be applied for routine analysis and quality control in laboratories for the cited drugs. Highlights: This work shows two examples to how to select a suitable UV spectrophotometric method to overcome the spectral overlap.

Canagliflozin stability study and ecofriendly chromatographic determination of its degradation product: A comparative study.

Canagliflozin is a newly approved drug for type II diabetes mellitus. A full stability study of canagliflozin was performed following international conference on harmonization strategies. The drug was stable against all conditions except oxidation where only one degradation product was separated and structurally elucidated using mass spectrometry and infrared spectroscopy. A green high-performance thin-layer chromatographic densitometric determination was developed and validated for the accurate quantification of canagliflozin and its main oxidative degradation product. Separation was performed on high-performance aluminum plates precoated with silica gel using acetone/ethanol (80:20, v/v) as a developing system and scanning at 290 nm. Retardation factor values were 0.64 and 0.81 and linearity ranges were 0.4-3.6 and 0.2-3.2 µg/band for the drug and the degradation product, respectively. It was a matter of interest to use green solvents with no harmful effects on the environment. The comparison between the proposed and the reported high-performance liquid chromatography method regarding greenness profile showed that the proposed method was greener and so could be used as an alternative method to the reported one with no environmental harm. Method validity was tested as per international conference on harmonization and method utility was verified by application to Invokana® tablets.