Simultaneous spectrophotometric quantitative analysis of velpatasvir and sofosbuvir in recently approved FDA pharmaceutical preparation using artificial neural networks and genetic algorithm artificial neural networks.

Two chemometric assisted spectrophotometric models were applied for the quantitative analysis of velpatasvir and sofosbuvir in their newly FDA approved pharmaceutical dosage form. The UV absorption spectra of velpatasvir and sofosbuvir showed certain degree of overlap which exhibited degree of difficulty for the choice of certain method provides simultaneous quantitative analysis of the cited drugs. Artificial neural networks and genetic algorithm artificial neural networks were the suitable model for the quantitative analysis of velpatasvir and sofosbuvir in their binary mixture. Experimental design and building the calibration set for the binary mixture were achieved to implement the described models. The proposed models were optimized with the aid of five-levels, two factors experimental design. Spectral region of 380-400 nm was rejected which resulted in 181 variables. GA reduced absorbance matrix to 72 and 36 variables for velpatasvir and sofosbuvir respectively. The models succeeded to estimate the studied drugs with acceptable values of root mean square error of calibration and root mean square error of prediction. The developed models were successfully applied to the quantitative analysis of the two drugs in Epclusa® tablets. The results were statistically compared with another published quantitative analytical method with no significant difference by applying Student t-test and variance ratio F-test.

Simultaneous Determination of Elbasvir and Grazoprevir in Their Pharmaceutical Preparation Using High-Performance Liquid Chromatographic Method.

A high-performance liquid chromatographic method has been developed for simultaneous determination of elbasvir and grazoprevir; two new Food and Drug Administration (FDA) approved drugs. The two drugs were co-formulated for treatment of hepatitis C virus in their combined pharmaceutical dosage form. The chromatographic separation has been achieved using a reversed phase BDS Hypersil C18 column with a mobile phase consists of acetonitrile:methanol (50:50, v/v) at flow rate of 1 mL/min and UV detection at 253 nm. Computational investigation for finding the best stationary phase revealed that C18 column fits better for the simultaneous chromatographic analysis of the studied drugs. Linearity, accuracy and precision have been found to be acceptable over the concentration range of 1-20 µg/mL for the studied drugs. The described method has been successfully applied for simultaneous determination of the studied drugs in their pharmaceutical dosage form.

Simultaneous determination of rosuvastatin and propranolol in their binary mixture by synchronous spectrofluorimetry.

Simultaneous determination of rosuvastatin calcium and propranolol hydrochloride using the first derivative synchronous spectrofluorimetry was described. This method involves measuring the synchronous fluorescence of both drugs in ethanol using, ∆ λ = 60 nm then the first derivative was recorded and the peak amplitudes were measured at 350 and 374 nm for rosuvastatin calcium and propranolol hydrochloride, respectively. Under the optimum conditions, the linear ranges of rosuvastatin calcium and propranolol hydrochloride were 0.2-2 µg/mL and 0.1-1 µg/mL, respectively. The method was used for quantitative analysis of the drugs in raw materials and pharmaceutical dosage form. The validity of the proposed method was assessed according to an international conference on harmonization (ICH) guidelines.

Validated Stability Indicating High Performance Liquid Chromatographic Determination of Lesinurad.

Lesinurad is a novel selective uric acid reabsorption inhibitor which has been newly approved for the treatment of the chronic gout. The behavior of lesinurad under various stress conditions (hydrolysis, oxidation, thermal and photolysis) has been investigated as per ICH guidelines. The drug has been found to be labile to acidic hydrolysis, basic hydrolysis and oxidation but stable in neutral, thermal and photolytic conditions. A high performance liquid chromatographic method has been developed for selective determination of the studied drug in the presence of its related degradation products. Good chromatographic resolution has been achieved using a reversed phase BDS Hypersil C18 stationary phase with an isocratic elution of a mobile phase consists of acetonitrile:water (65:35, v/v) at a flow rate of 1 mL/min and UV detection at 290 nm. Two degradation products have been identified by IR and mass spectral scans. The method was validated according to ICH guidelines. The linearity range has been found to be acceptable over the concentration range of 1-20 µg/mL. The developed method has been successfully applied for the estimation of lesinurad in its pharmaceutical dosage form and could be used for the routine analysis of the studied drug in the quality control laboratories.

Different spectrophotometric methods applied for the analysis of simeprevir in the presence of its oxidative degradation product: Acomparative study.

Five simple spectrophotometric methods were developed for the determination of simeprevir in the presence of its oxidative degradation product namely, ratio difference, mean centering, derivative ratio using the Savitsky-Golay filters, second derivative and continuous wavelet transform. These methods are linear in the range of 2.5-40µg/mL and validated according to the ICH guidelines. The obtained results of accuracy, repeatability and precision were found to be within the acceptable limits. The specificity of the proposed methods was tested using laboratory prepared mixtures and assessed by applying the standard addition technique. Furthermore, these methods were statistically comparable to RP-HPLC method and good results were obtained. So, they can be used for the routine analysis of simeprevir in quality-control laboratories.

Application of different spectrophotometric methods for simultaneous determination of elbasvir and grazoprevir in pharmaceutical preparation.

The first three UV spectrophotometric methods have been developed of simultaneous determination of two new FDA approved drugs namely; elbasvir and grazoprevir in their combined pharmaceutical dosage form. These methods include simultaneous equation, partial least squares with and without variable selection procedure (genetic algorithm). For simultaneous equation method, the absorbance values at 369 (λmax of elbasvir) and 253nm (λmax of grazoprevir) have been selected for the formation of two simultaneous equations required for the mathematical processing and quantitative analysis of the studied drugs. Alternatively, the partial least squares with and without variable selection procedure (genetic algorithm) have been applied in the spectra analysis because the synchronous inclusion of many unreal wavelengths rather than by using a single or dual wavelength which greatly increases the precision and predictive ability of the methods. Successfully assay of the drugs in their pharmaceutical formulation has been done by the proposed methods. Statistically comparative analysis for the obtained results with the manufacturing methods has been performed. It is noteworthy to mention that there was no significant difference between the proposed methods and the manufacturing one with respect to the validation parameters.

Simeprevir oxidative degradation product: Molecular modeling, in silico toxicity and resolution by synchronous spectrofluorimetry.

In this article, one of the potential degradation products of the novel antiviral drug simeprevir was isolated and characterized by means of infrared (IR) and mass spectrometry. Moreover, comparative molecular docking, ADMET (absorption, distribution, metabolism, excretion - toxicity) and insilico toxicity prediction studies were applied to evaluate the activity of simeprevir and its degradation product. Furthermore,a simple, accurate and selective second derivative synchronous spectrofluorimetric method was developed for the determination of simeprevir in the presence of its oxidative degradation product.The synchronous fluorescence spectra of both compounds were measured in ethanol at pH 2.0 usingΔλ of 140 nm and the peak amplitude of the second derivative spectra were measured at 442 nm. The method was rectilinear over the concentration range of 0.2 to 2.0 µg/ml and validated according to the ICH (International Conference on Harmonization) guidelines. Moreover, the method was statistically compared to the reverse-phase high-performance liquid chromatography (RP-HPLC) method and good results were obtained.

Simultaneous Spectrophotometric Determination of Elbasvir and Grazoprevir in a Pharmaceutical Preparation.

Three UV spectrophotometric methods have been developed for the simultaneous determination of two new Food and Drug Administration-approved drugs, elbasvir (EBV) and grazoprevir (GRV), in their combined pharmaceutical dosage form. These methods include dual wavelength (DW), classic least-squares (CLS), and principal component regression (PCR). To achieve the DW method, two wavelengths were chosen for each drug in a way to ensure the difference in absorbance was zero from one drug to the other. GRV revealed equal absorbance at 351 and 315 nm, for which the distinctions in absorbance were measured for the determination of EBV. In the same way, distinctions in absorbance at 375 and 334.5 nm were measured for the determination of GRV. Alternatively, the CLS and PCR models were applied to the spectra analysis because the synchronous inclusion of many unreal wavelengths rather than using a single wavelength greatly increased the precision and predictive ability of the methods. The proposed methods were successfully applied to the assay of these drugs in their pharmaceutical formulation. The obtained results were statistically compared with manufacturing methods. The results conclude that there was no significant difference between the proposed methods and the manufacturing method with respect to accuracy and precision.

Application of an HPLC Method for Selective Determination of Phenazopyridine Hydrochloride: Theoretical and Practical Investigations.

HPLC method was developed for the selective determination of phenazopyridine hydrochloride (PAP) in the presence of its computationally selected metabolite. Density functional theory was applied as a computational model to study the energy of PAP metabolites, and the results revealed that 2,3,6-triaminopyridine (TAP) is the most stable metabolite. Good resolution and separation of PAP from TAP was achieved using a reversed-phase BDS Hypersil C18 column with a mobile phase consisting of acetonitrile-water (75 + 25, v/v) at flow rate of 1 mL/min and with UV detection at 280 nm. The linear regression analysis data for the calibration plot of PAP showed a good linear relationship over the concentration range of 5-45 µg/mL, with an LOD of 0.773 µg/mL. Moreover, a theoretical investigation of the relationship between the stationary phase and the studied molecules was performed to confirm the experimental results. The proposed method was successfully applied for the selective determination of PAP in pharmaceutical formulation. In addition, the obtained results were statistically compared to a reported method, with no significant differences found between the investigated method and the reported one with respect to accuracy and precision.

Experimental design of membrane sensor for selective determination of phenazopyridine hydrochloride based on computational calculations.

Computational study has been done electronically and geometrically to select the most suitable ionophore to design a novel sensitive and selective electrochemical sensor for phenazopyridine hydrochloride (PAP). This study has revealed that sodium tetraphenylbarate (NaTPB) fits better with PAP than potassium tetrakis (KTClPB). The sensor design is based on the ion pair of PAP with NaTPB using dioctyl phthalate as a plasticizer. Under optimum conditions, the proposed sensor shows the slope of 59.5 mV per concentration decade in the concentration range of 1.0 × 10(-2)-1.0 × 10(-5) M with detection limit 8.5 × 10(-6) M. The sensor exhibits a very good selectivity for PAP with respect to a large number of interfering species as inorganic cations and sugars. The sensor enables track of determining PAP in the presence of its oxidative degradation product 2, 3, 6-Triaminopyridine, which is also its toxic metabolite. The proposed sensor has been successfully applied for the selective determination of PAP in pharmaceutical formulation. Also, the obtained results have been statistically compared to a reported electrochemical method indicating no significant difference between the investigated method and the reported one with respect to accuracy and precision.