Combined Pharmaceutical Dosage Form Research Articles

Development and validation of stability indicating thin‐layer chromatography methods for simultaneous estimation of Bisoprolol Fumarate and Hydrochlorothiazide

AbstractFor the simultaneous estimation of Bisoprolol Fumarate and Hydrochlorothiazide in combined pharmaceutical dosage form, a simple, selective, rapid, and precise stability indicating high‐performance thin‐layer chromatography method has been developed and validated.The proposed high‐performance thin‐layer chromatography technique includes the usage of high‐performance thin‐layer chromatography plates (Merck) pre‐coated with silica gel 60F254 on aluminum sheets and a cellular segment comprising of methanol:acetonitrile (8:2, v/v). The densiometric measurement of both drugs was performed in the absorbance mode at 223 nm. The method has been used to accurately estimate Bisoprolol Fumarate and Hydrochlorothiazide in a combined tablet dosage form. Both the drugs had been subjected to acid‐alkali hydrolysis, photolytic, thermal, and oxidation degradation and each of them had been discovered to be prone to acid‐alkali hydrolysis, photolytic, thermal, and oxidation degradation. The developed stability‐indicating analytical method was validated. The various validation parameters checked are linearity, inter‐day and intra‐day precision, robustness, accuracy, and so forth.The degradation products obtained were well resolved from the pure drugs with significantly different Rf values. The method can be utilized for stability‐indicating analysis since it successfully separates the drug from its degradation products. The method was successfully validated and validation results are within the acceptable range of International Council for Harmonization guidelines.

Method Development and Validation for the estimation of Amlodipine and Perindopril in Bulk and Pharmaceutical Dosage Form

Literature survey reveals that few spectrophotometric, high performance liquid chromatographic (HPLC)and High performance thin layer chromatographic (HPTLC)methods were reported for the estimation of Amlodipine and perindopril in bulk and combined pharmaceutical dosage forms. But there is no any stability indicating high performance liquid chromatography study is reported for amlodipine. So the present study was aimed to development of simple, accurate, rapid and economical HPLC stability indicating assay method were established for the determination of Amlodipine and Peridopril in bulk and tablet dosage form. A High-performance liquid chromatograph WATERS, software: Empower 2,2695 separation module, 996 PDA detector, using Phenomenex Luna C18 (4.6mm×250mm) 5µm or equivalent column, with mobile phase composition of Methanol: Phosphate Buffer pH3.0 (70:30v/v) was used. The flow rate of 1.0ml min-1 and effluent was detected at 230nm. The retention time of Amlodipine and Perindopril was found to be 1.870min and 2.499minutes respectively. Linearity was observed over concentration range of 10-50µg ml-1 for Amlodipine and 16-80µg ml-1 for Perindopril respectively. The accuracy of the proposed method was determined by recovery studies and the Amlodipine was found to be 99.1% and Perindopril was found to be 98.8% respectively. The proposed method is applicable to routine analysis of Amlodipine and Perindopril in bulk and pharmaceutical formulations. The proposed method was validated for various ICH parameters like linearity, limit of detection, limits of quantification, accuracy, precision, range and specificity.

Univariate and Multivariate Determination of Dapagliflozin and Saxagliptin in Bulk and Dosage Form.

Dapagliflozin is a sodium glucose cotransporter-II inhibitor while saxagliptin is a dipeptidyl peptidase-4 inhibitor. Both are used to manage type 2 diabetes mellitus. The aim of this work is to develop four simple, accurate, and precise UV-spectrophotometric methods, three univariate and one multivariate, for the estimation of dapagliflozin and saxagliptin in their pure and marketed dosage forms. Method (A) is based on the ratio difference method; Method (B) is ratio subtraction with constant multiplication; while Method (C) is a second derivative method and Method (D) is a partial least-squares method. The calibration curves for dapagliflozin and saxagliptin were linear within the concentration range of 2.50-50.0 μg/mL and 5.0-60.0 μg/mL, respectively. The specificity of the proposed methods was studied by analyzing different laboratory-prepared mixtures and their combined pharmaceutical dosage form. According to the International Council for Harmonisation guidelines, the three proposed methods were validated regarding the accuracy, precision, and specificity. Method (D), partial least-squares, was employed for the determination of the same mixture over a wavelength range of 205-300 nm. A statistical comparison was performed between the results of the proposed methods and those of a reported spectrophotometric method and no statistically significant difference was detected at 95% confidence limit regarding both precision and accuracy. Four accurate, specific, and precise UV-spectrophotometric methods for dapagliflozin and saxagliptin testing and estimation were successfully utilized and validated. The examined methods are simple and do not involve sophisticated and expensive instruments. They could be effectively employed in quality control laboratories for routine examination of the investigated drugs in their pure powdered or combined pharmaceutical formulations.

Different spectrophotometric methods for simultaneous determination of lesinurad and allopurinol in the new FDA approved pharmaceutical preparation; additional greenness evaluation

Lesinurad and allopurinol have been formulated in a combined dosage form providing a new challenge for the treatment of gout attacks. Two mathematical based spectrophotometric methods, area under the curve, and artificial neural networks have been developed for simultaneous determination of lesinurad and allopurinol in pure form and in combined pharmaceutical dosage form. Area under the curve has been utilized to resolve the spectral overlap between lesinurad and allopurinol. Values of area under the curve and area absorptivity were measured at two selected wavelength ranges of 242–250 nm and 255–265 nm. Two mathematically constructed equations have been used to determine the concentrations of the drugs under the study. Advanced chemometry based model, artificial neural network, has been developed utilizing the UV spectral data of lesinurad and allopurinol through various defined steps. A five-level, two-factor experimental design was used to construct 25 mixtures. Thirteen mixtures were used to set up the calibration model and 12 mixtures were used to construct a validation set. The artificial neural network model was optimized to enable precise spectrophotometric determination of the drugs under the study. The described mathematically bases spectrophotometric methods have been successfully applied to the determination of lesinurad and allopurinol in the new combined, Duzallo® tablets. Furthermore, the greenness of the described methods was assessed using four different tools namely, the national environmental method index, the analytical eco-scale, the green analytical procedure index and the AGREE evaluation method. The proposed methods showed more adherence to the greenness characters in comparison to the previously reported HPLC method.

Standardized Analytical Procedure for Routine Testing of Amlodipine Besilate and Enalapril Maleate Simultaneously in In-vitro Samples

>This study develops a standardized methodology for routine analysis of in-vitro samples of amlodipine besilate and enalapril maleate concurrently in immediate-release tablet dosage forms. UV-detection was performed at absorption maxima of 237.20 nm and 217.00 nm for amlodipine besilate and enalapril maleate, respectively; 6.8 pH phosphate buffer was used as dissolution media for 30 mintues, on USP II (Paddle) dissolution apparatus, at 50 RPM and 37.0 ± 0.5oC. The fallouts of the analysis were endorsed statistically. Results were satisfactory in the arrays of 1–19 μg mL-1 for amlodipine besilate and 1–9 μg mL-1 for enalapril maleate. The analysis results exhibited that the projected simultaneous method is modest, swift, precise, and accurate and used for the repetitive analysis of dissolution samples of amlodipine besilate and enalapril maleate in combined pharmaceutical dosage forms (tablets).

Chemometric-Based AQbD and Green Chemistry Approaches to Chromatographic Analysis of Remogliflozin Etabonate and Vildagliptin.

According to the green chemistry approach, during method development, the usage of toxic and carcinogenic organic solvents should be avoided or minimized for the safety of the environment and analysts. The chromatographic methods such as reverse-phase high-pressure liquid chromatography (RP-HPLC) and high-performance thin-layer chromatography (HPTLC) include the usage of class 2 organic solvents as per the International Council for Harmonization (ICH) Q3C (R6) guideline. The chromatographic analysis by HPTLC requires less organic solvent compared to the RP-HPLC method. Hence, HPTLC-based chromatographic analysis of vildagliptin (VIL) and remogliflozin etabonate (RMG) has been carried out using green chemistry and analytical quality by design (AQbD) approaches. The principal component analysis (PCA)-based chemometric analysis was applied for the identification of critical method variables (CMV) for the development of the method. The design of experiments (DoE)-based Box-Behnken design (BBD) was applied for response surface modeling (RSM) and optimization of CMV. The analytical design space (ADS) and analytical control point were navigated for the development of the HPTLC method as per the quality target analytical profile. The chromatographic analysis of VIL and RMG was carried out using silica gel G60 F254 as the stationary phase and acetone-ethyl acetate-water-triethylamine (7.0 + 2.5 + 0.3 + 0.2, v/v) as the mobile phase. The HPTLC method was validated as per the ICH Q2 (R1) guideline. The HPTLC method was applied for the assay of fixed-dose combinations (FDCs) of VIL and RMG, and the results were found to comply with their labeled claim. The developed method included the usage of organic solvents that belong to the class 3 category as per the ICH Q3C (R6) guideline. Hence, the developed method can be used as an eco-friendly alternative to published chromatographic methods for quality control and routine analysis of FDCs of VIL and RMG in the pharmaceutical industry. Chromatographic analysis of VIL and RMG using green chemistry and AQbD approaches. Application of the method for assay of drugs in their combined pharmaceutical dosage forms.

Smart spectrophotometric methods for stability assessment of two co-formulated antigout drugs

Simple, sensitive and accurate stability indicating spectrophotometric methods have been developed for the simultaneous determination of probenecid, colchicine as well as colchicine degradation product in their ternary mixture. Probenecid was firstly assayed using the double divisor ratio spectra derivative method. On the other hand, three spectrophotometric methods, namely: ratio difference, derivative ratio and mean centering of ratio spectra, have been suggested for the simultaneous quantification of colchicine and its degradation product. The obtained calibration curves were linear at 2.5–30.0 μg/mL, 0.5–25.0 μg/mL and 1.0–13.0 μg/mL for probenecid, colchicine and colchicine degradation product, respectively. The investigated methods were validated in accordance with the International Council for Harmonisation guidelines and were effectively used for quantification of probenecid and colchicine in their bulk powders and combined pharmaceutical dosage form.

DoE-Based Analytical Failure Modes Critical Effect Analysis (AFMCEA) to a Multipurpose-RP-HPLC Method for the Estimation of Multiple FDC Products of Metformin Hydrochloride Using an Analytical Quality by Design Approach.

Metformin hydrochloride is the first-choice antihyperglycemic agent and its several fixed-dose combinations (FDCs) with pioglitazone hydrochloride, sitagliptin phosphate, and gliclazide are used for the management of type II diabetes. Numerous reversed-phase HPLC (RP-HPLC) and HPTLC methods have been reported for estimation of FDCs of metformin but each FDC needs separate and dedicated chromatographic conditions for analysis. No RP-HPLC method has been reported yet which promotes synchronous estimation of FDC products of metformin to save time, resources, cost, and organic solvent for analysis. Hence, an economical and eco-friendly RP-HPLC method was developed for the synchronous estimation of FDCs of metformin hydrochloride using an enhanced analytical quality by design (AQbD) approach. The AQbD approach was implemented using analytical-failure modes critical effects analysis (FMCEA) as per International council for harmonisation (ICH) Q8 and Q9 guidelines. The analytical-FMCEA was applied by identification of potential analytical failure modes followed by their risk assessment by a risk priority number (RPN) ranking and filtering method. Further, the risk of critical failure modes was controlled and mitigated by a design of experiments (DoE)-based Box-Behnken design by navigation of method operable design ranges (MODR). From the set of control strategies, the RP-HPLC method was developed using a Shim-Pack ODS C18 column and acetonitrile-0.1% triethylamine (40:60, v/v) triethylamine in water (pH 3.2 adjusted by perchloric acid). The method was found to be validated as per ICH Q2 (R1) guideline. The synchronous estimation of different FDCs of metformin hydrochloride was carried out by the developed method. The developed method can be used as a multipurpose chromatography method as an alternative to published chromatography methods for QC of FDCs of metformin hydrochloride in the pharmaceutical industry. The multipurpose RP-HPLC method has been developed and validated for the synchronous estimation of multiple combined pharmaceutical dosage forms of metformin hydrochloride. The method was developed by the implementation of the AFMCEA-based AQbD approach as per the regulatory requirements of ICH.

Chemometric and DoE-Based Analytical Quality Risk Management to HPTLC Method for Simultaneous Estimation of Metronidazole and Norfloxacin.

According to the upcoming ICH Q14 guideline, the development of an analytical method by the implementation of the AQbD approach based on analytical quality risk management and design of experiments will become a regulatory requirement for the registration of new drug substances and products. In literature, the HPTLC method has not been reported yet for simultaneous estimation of metronidazole and norfloxacin. Hence, the robust HPTLC method has been developed and validated for simultaneous estimation of metronidazole and norfloxacin using QRM and the DoE-based enhanced AQbD approach. The principal component analysis was applied for chemometric-based risk assessment of method risk parameters. The high-risk method parameters were optimized by a DoE-based full-factorial design. The MODR and control strategy was estimated for quality risk management throughout the lifecycle of the HPTLC method. The HPTLC method was developed using silica gel 60F254 as stationary phase and acetonitrile-methanol-formic acid-ammonia (9.5 + 0.5 + 0.5 + 0.3, v/v) as mobile phase. The developed method was validated as per ICH Q2 (R1) guideline. The developed method was applied for the assay of combined pharmaceutical dosage forms of metronidazole and norfloxacin and results were found in compliance with their respective labeled claim.

QUANTITATIVE DETERMINATION AND VALIDATION OF ETORICOXIB AND PARACETAMOL COMBINED TABLET DOSAGE FORM BY REVERSE PHASE-HPLC

An RP-HPLC technique was used to produce a cost-effective simultaneous quantification of Etoricoxib and Paracetamol in combined pharmaceutical tablet dosage forms. The approach was validated for Etoricoxib and Paracetamol using ICH recommendations over a range of 20-120ppm and 20-200ppm, respectively. At a temperature of 250C±0.50C, an analytical column PURITAS™ EXIMIUS C18, 250mmx4.6mm, 5 microns was utilized. At a flow rate of 1.0 ml/min, the mobile phase was acetonitrile and 0.1 percent acetic acid in water in a 70:30V/V ratio. The elution was examined using a PDA detector with a detection wavelength of 235nm. The retention times for Etoricoxib and paracetamol are 4.2 and 2.1 minutes, respectively. The percentage recoveries for Etoricoxib and paracetamol were 98.28% and 102.1%, respectively. The RSD values are not greater than 2%.

Comparison of Chemometric assisted UV Spectrophotometric and RP-HPLC Method for the simultaneous determination of Ofloxacin and Tinidazole in their Combined dosage form

In present work, chemometric-assisted UV spectrophotometric methods as well as RP-HPLC method were developed for the simultaneous estimation of Ofloxacin and Tinidazole in their combined pharmaceutical dosage form. The two chemometric methods i.e. principle component regression (PCR) and partial least square regression (PLS) were successfully applied to quantify each drug in mixture using UV absorption spectra in range of 280 to 320nm at ∆λ of 0.5nm. Chemometric model development was done using 24 binary mixture solutions and 12 solutions were used for validation of model. The chemometric-assisted analysis does not require any prior separation step. In addition, RP-HPLC method was also developed using THERMOSIL C18 column with a mobile phase consisting ofAcetonitrile: Phosphate Buffer (85:15% v/v), flow rate of 1 ml/min and quantification was achieved using UV detector at 300 nm. The methods were successfully applied for the simultaneous determination of these drugs in synthetic mixture. The results obtained for analysis by PCR and PLS methods were compared with RP-HPLC method and a good agreement was found.

Comparative evaluation of different mathematical models for simultaneous UV spectrophotometric quantitative analysis of velpatasvir and sofosbuvir

Velpatasvir and sofosbuvir are new drugs prescribed in a combined pharmaceutical dosage form that pose a new challenge for the treatment of chronic hepatitis C. In this work, a comparative evaluation of the classical mathematical model, simultaneous equations, and the advanced mathematical model, partial least squares, for the spectrophotometric quantitative analysis of velpatasvir and sofosbuvir in bulk powder and in the new combined pharmaceutical dosage form was presented. The mathematical simultaneous equation method was used to resolve the overlap between velpatasvir and sofosbuvir. The absorbance and absorbativity values at 255 and 244.8 were used to construct two mathematical equations required for spectrophotometric quantitative analysis of the drugs under study. Partial least squares, an advanced mathematical tool dealing with the full spectral data of velpatasvir and sofosbuvir, was also introduced. An experimental design for the calibration sets and validation sets for the binary mixture of the drugs under study were created. The model was optimized based on a five-level, two-factor experimental design. Pre-processing of the spectral data was applied and resulted in the exclusion of the spectral region from 200 to 230 nm due to noise. The described methods were successfully applied to the spectrophotometric quantitative analysis of velpatasvir and sofosbuvir in Epclusa® tablets.

STABILITY INDICATING HPLC METHOD DEVELOPMENT AND VALIDATION FOR SIMULTANEOUS ESTIMATION OF EMTRICITABINE, DOLUTEGRAVIR AND TENOFOVIR ALAFENAMIDE IN THEIR COMBINED PHARMACEUTICAL DOSAGE FORM

A simple, rapid, precise and accurate reversed phase HPLC stability indicating method was developed for simultaneous determination of emtricitabine (ECT), dolutegravir (DOL) and tenofovir alafenamide (TEN) in their combined dosage marketed formulation. The chromatographic separation was achieved on Hypersil BDS C18 (250  4.6 mm, 5.0 µ) column using 0.5 M potassium dihydrogen phosphate buffer: acetonitrile (80: 20, v/v), pH 3.5 ± 0.1 maintained by 0.1 % o-phosphoric acid as mobile phase at a flow rate of 1.0 mL/min and monitored at 260 nm. All three analytes were resolved at retention times of 5.777, 6.783, 8.393 min for ECT, DOL, and TEN respectively. The assay performance of the present developed method was validated for various parameters like system suitability, linearity, accuracy, precision, robustness, limit of detection and quantification. The calibration curves were linear over concentration ranges of 12.5-75.0, 50.0-300, and 6.25-37.5 μg/ml for DOL, ECT, and TEN, respectively with correlation coefficients  0.9995. All three analytes were subjected to various stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. Considerable degradation was found in alkaline condition. The present method demonstrated to be effective stability-indicating by resolution of the analytes from their forced-degradation products. The validated method was successfully applied for the simultaneous estimation three drugs in their combined pharmaceutical dosage form Spegra.

DEVELOPMENT AND VALIDATION OF RP-HPLC METHOD FOR SIMULTANEOUS DETERMINATION OF RELATED SUBSTANCES PRESENT IN THE PHARMACEUTICAL DOSAGE FORM OF EMTRICITABINE, TENOFOVIR ALAFENAMIDE AND DOLUTEGRAVIR

A novel, rapid and an accurate reversed phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the simultaneous quantification of emtricitabine and tenofovir related impurities namely emtricitabine s-oxide (emtricitabine impurity-A) and tenofovir (S)-propanol (tenofovir impurity-A), respectively in the combined pharmaceutical dosage form of emtricitabine, dolutegravir and tenofovir alafenamide. The separation was accomplished on Inertsil ODS C18 (250  4.6 mm, 5μ) column using 0.5 M potassium dihydrogen phosphate buffer: acetonitrile (80: 20, v/v), pH 4.5 ± 0.1 maintained by 0.1 % o-phosphoric acid as mobile phase delivered at a flow rate of 1.0 mL/min. Detection was carried out at 260 nm. Emtricitabine impurity-A and tenofovir impurity-A analytes were eluted at retention times of 10.5 and 16.6 min, respectively. The developed method was successfully validated for various parameters like system suitability, linearity, accuracy, precision, robustness, limit of detection and quantification in accordance with ICH guidelines. The calibration curves were linear over the concentration range of 0.125-7.500 μg/ml for emtricitabine impurity-A and tenofovir impurity-A with correlation coefficients  0.998. The validated method was successfully applied for the simultaneous estimation of emtricitabine s-oxide (emtricitabine impurity-A) and tenofovir (S)-propanol (tenofovir impurity-A) in fixed-dose combination comprising of emtricitabine, dolutegravir and tenofovir alafenamide.

Risk Assessment-Based Enhanced Analytical Quality-by-Design Approach to Eco-Friendly and Economical Multicomponent Spectrophotometric Methods for Simultaneous Estimation of Montelukast Sodium and Bilastine

Concomitant montelukast and bilastine are used as additive therapy for seasonal allergic rhinoconjuctivitis and mild to moderate asthma. According to a literature review, no UV-visible spectrophotometric method has been reported yet for simultaneous estimation of montelukast sodium and bilastine in their combined pharmaceutical dosage forms. Five different multicomponent spectrophotometric methods were therefore developed and validated for simultaneous estimation of montelukast sodium and bilastine using a risk assessment-based enhanced analytical quality-by-design approach. The identification and assessment of method risk parameters were carried out using the risk priority number ranking and filtering method according to the International Conference on Harmonization (ICH) Q9 guideline. The wavelength for detection and solvents such as 0.1 N NaOH and 0.1 N HCl were found to be critical method parameters for the development of the target methods. The developed methods were validated as per the ICH Q2(R1) guideline. The developed and validated methods were applied for assay of combined pharmaceutical dosage forms of montelukast sodium and bilastine and results were found to be in good agreement with their label claims. The developed methods did not include the usage of any organic solvent and are a good alternative to the costly chromatography method. Hence, the methods are eco-friendly and economical for the simultaneous estimation of bilastine and montelukast sodium. Five multicomponent spectrophotometric methods were developed for simultaneous estimation of montelukast sodium and bilastine using a risk-based analytical quality-by-design approach. An assay of combined tablet dosage forms of montelukast sodium and bilastine was then carried out using the developed methods.

Spectral analysis of severely overlapping spectra based on newly developed mathematical filtration techniques and ratio spectra manipulations: An application to the concurrent determination of dapoxetine and sildenafil in combined dosage form

BackgroundDapoxetine hydrochloride (DAP) and sildenafil citrate (SIL) have proven clinically effective in the treatment of comorbid conditions like erectile dysfunction and premature ejaculation. The analysis of DAP and SIL combinations represents a challenge because of the severe overlap of these compounds’ spectra. Six newly developed methods were proven effective for resolving such a challenging overlap. They also exhibited the advantage of simplicity as they depend on the zero-order spectrum and only require simple mathematical handling. ObjectiveWe suggested six simple, precise, and sensitive spectrophotometric methods based on mathematical filtration techniques and ratio spectra manipulations to resolve the spectra of DAP and SIL in their bulk and combined pharmaceutical dosage form and estimate the relevant individual concentrations. MethodsThe first three methods were based on the zero-order range and involved modest mathematical manipulations. They are the induced dual-wavelength, Fourier self-deconvolution, and absorptivity factor spectrophotometric methods. Three other methods that are based on ratio spectra manipulation were developed: ratio difference, mean centering of the ratio spectra, and derivative ratio spectrum. ResultsWe determined the performance of the suggested methods for estimating DAP and SIL in their laboratory mixtures and their combined pharmaceutical dosage form. The linear ranges for DAP and SIL were 1–40 µg/ml and 2–60 µg/ml, respectively. The detection limits were in the 0.18–1.10 µg/ml range for DAP and in the 0.68–1.11 µg/ml range for SIL. The developed methods were validated as per the ICH guidelines for linearity, detection limit, quantitation limit, selectivity, precision, and accuracy. Normal probability, interval, and Tukey’s simultaneous significant difference plots were utilized to confirm and better visualize the analysis of variance test results. Statistically, no significant difference was observed to exist between results obtained from the hereby developed and the previously reported methods.

Validated RP-HPLC Method for Simultaneous Estimation of Atenolol, Hydrochlorothiazide and Losartan Potassium in Bulk and Pharmaceutical Dosage Form

A simple, specific, accurate, and precise reverse phase high performance liquid chromatographic (RP-HPLC) method was developed for the simultaneous estimation of Atenolol, Hydrochlorothiazide and Losartan potassium in bulk and pharmaceutical dosage form. The separation was carried out using Hypersil C18, 250 ×4.6 mm, 5µm column with mobile phase consisted mixture of Acetonitrile and Potassium dihydrogen ortho phosphate buffer in the ratio of 40:60 (V/V) delivered at a flow rate of 1.5 mL / min and effluents were monitored at 225 nm. The selected chromatographic conditions were effective separation of these drugs. And the retention times of Atenolol, Hydrochlorothiazide and Losartan potassium were found to be 1.46, 2.21 and 3.30 min respectively. The proposed method was found to be linear in the range of 50-150 μg/mL,12.5-37.50 μg/mL, and 50-150 μg/mL for Atenolol, Hydrochlorothiazide and Losartan potassium respectively. The recovery of drugs was found to be 97.56 %, 97.72 % and 98.06 % respectively. The proposed method was validated as per ICH guidelines and it was found to be accurate, precise and robust, and it was applied to the estimation of Atenolol, Hydrochlorothiazide and Losartan potassium in combined tablet dosage form and it can also be used for routine quality control analysis of these drugs in biological samples either alone or in combined pharmaceutical dosage forms.

Simultaneous Determination of Cefixime, Cefdinir and Clavulanic Acid by High Performance Liquid Chromatography

In this study, two cephalosporin groups of antibiotics (cefepime and cefixime) and their combinations with clavulanic acid, beta lactamase inhibitor, were simultaneously analyzed by HPLC method. The optimum separation was carried out on MZ C18 column (250 × 4.6 mm; i.d. 5 μm) with mobile phase consisting of an acetonitrile – 0.01% phosphoric acid (pH 2.5) (15 : 85, v/v) binary mixture. Detection was performed using a diode array detector at 228 nm. Under these experimental conditions, the analysis was accomplished in about 10 min. The developed method is specific, linear, sensitive, accurate, precise, and robust. The method was completely validated showing satisfactory data for all the parameters tested. Finally, the proposed method was successfully applied to two combined pharmaceutical dosage forms containing cefepime with clavulanic acid and cefixime with clavulanic acid.

Development and Validation of RP-HPLC Method for the estimation of Sofosbuvir and Ledipasvir in combined dosage form

Nowadays scientists aim at developing generic and specific methods for drugs in combined pharmaceutical dosage forms. The main aim was to develop and carry out validation using precision and accuracy for Sofosbuvir and Ledipasvir by applying RP-HPLC method. The dosage form in fixed combination of Sofosbuvir-Ledipasvir helps in effective treatment of genotypes of chronic hepatitis C virus. This combination of Sofosbuvir-Ledipasvir was the first FDA approved direct acting antiviral to treat hepatitis C. Both the drugs were optimized using mobile phase as acetonitrile: 0.1% orthophosphoric acid (55:50v/v) with pH 3.0. The mobile phase was optimized at maximum wavelength of 283nm. The separation was achieved using C18 Cosmosil (4.6 x 250mm) column with a particle size of 5µ. The method was specific eluting retention times of 3.7 for Sofosbuvir and 6.0 for Ledipasvir. Intra and interday precision was carried and %RSD was found to be less than 2%. The results were found to be accurate with percentage recovery of 99.76% and 99.10% for Sofosbuvir and Ledipasvir respectively. Linearity was carried out in the concentration ranging from 40-200µg/mL and 9-45µg/mL for Sofosbuvir and Ledipasvir respectively. Both the drugs showed the regression coefficient of 0.999. Deliberate changes in flow rate, pH and wavelength were made and found that method was robust. The developed method was found to be accurate, simple, specific, robust and precise for the simultaneous estimation of Sofosbuvir and Ledipasvir in tablet dosage form.

Different chemometric assisted approaches for spectrophotometric quantitative analysis of lesinurad and allopurinol

Three chemometric assisted spectrophotometric approaches were designed for precise quantitative analysis of lesinurad and allopurinol, in their recently FDA approved combination pharmaceutical dosage form. By utilizing the recorded absorption spectral data of lesinurad and allopurinol mixtures, principle component regression, partial least squares and genetic algorithm partial least squares were developed and compared for the spectrophotometric quantitative analysis of the cited drugs in their binary mixture. Experimental design for different concentrations of the studied drugs was done based on the spectral sensitivity and the commercial ratio of the two drugs in the combined pharmaceutical dosage form. Optimization of the described models was done using five-levels, two factors experimental design principle. Quantitative assay of the two drugs in Duzallo® tablet was successfully done and the data obtained was statistically compared with the results of another published HPLC quantitative analytical method.