Efficient HPTLC-dual wavelength spectrodensitometric method for simultaneous determination of sofosbuvir and daclatasvir: Biological and pharmaceutical analysis

A new fluorescence probe for sofosbuvir analysis in dosage form and spiked human plasma

A simple, rapid, and low-cost technique was developed to allow reliable analysis of the anti-hepatitis C drug sofosbuvir in bulk, tablet form, and spiked human plasma. This method depends on the ability of sofosbuvir to quench the fluorescence of the newly synthesized 2-amino-3-cyano-4,6-dimethylpyridine (reagent 3). Elemental analysis and spectral data were used to validate the structure of the synthesized reagent. The newly synthesized reagent exhibited a satisfactory level of fluorescence emission at 365 nm after excitation at 247 nm. All experimental variables that might affect the quenching process were analyzed and optimized. Linearity, range, accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ) were all validated in accordance with the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. The concentration range was shown to be linear between 0.1 and 1.5 μg/mL. The technique was effectively utilized for sofosbuvir analysis in both its tablet dosage form and spiked human plasma, with mean percentage recoveries of 100.13 ± 0.35 and 94.26 ± 1.69, respectively.

Quantification of Suvorexant in Human Urine Using a Validated HPTLC Bioanalytical Method

Suvorexant (SUV) is a new sedative/hypnotic medicine that is recommended to treat insomnia. It is an important medicine from a forensic point of view due to its sedative/hypnotic and depressant effects. To the best of our knowledge, high-performance thin-layer chromatography (HPTLC) bioanalytical methods have not been published to measure SUV in human urine and pharmaceutical samples. Accordingly, this study was designed and validated a sensitive and rapid bioanalytical HPTLC method to determine SUV in human urine samples for the very first time. The densitometric measurement of SUV and the internal standard (IS; sildenafil) was performed on glass-coated silica gel normal-phase-60F254S TLC plates using a mixture of chloroform and methanol (97.5:2.5 v/v) as the eluent system. Both the SUV and IS were detected at a wavelength of 254 nm. Both analytes were extracted using the protein precipitation technique utilizing methanol as the solvent. For the IS and SUV, the Rf values were 0.09 and 0.45, respectively. The proposed bioanalytical method for SUV was linear in the 50-1600 ng/band range. The current bioanalytical technique was linear, precise (% RSD = 3.28-4.20), accurate (% recovery = 97.58-103.80), robust (% recovery = 95.31-102.34 and % RSD = 2.81-3.15), rapid, and sensitive (LOD = 3.73 ng/band and LOQ = 11.20 ng/band). These findings suggested that the current bioanalytical method can be regularly used to determine SUV in wide varieties of urine samples.

Comparative study of four innovative earth-friendly platforms for rapid analysis of daclatasvir dihydrochloride: Application on different matrices

BACKGROUND

Daclatasvir dihydrochloride has important roles not only in the management of COVID-19 pandemic symptoms but also in the treatment of chronic hepatitis C infection.

OBJECTIVE

The current research presents four novel and simple platforms including silver-nanoparticles spectrophotometric technique and three electrochemical conductometric ones for daclatasvir analysis in its tablet, biological fluids, and dissolution media.

METHODS

The spectrophotometric platform involved the synthesis of silvernanoparticles through a redox reaction between the reducing agent (daclatasvir) and the oxidizing agent (silver nitrate) in presence of polyvinylpyrrolidone as a stabilizing agent. The produced silver-nanoparticles have an intense surface plasmon resonance peak at 421 nm where the measured absorbance values were utilized for quantitative spectrophotometric determination of daclatasvir. While the electrochemical conductometric platforms involved the reaction of daclatasvir with three different precipitating reagents (silver nitrate, phosphomolybdic acid, and ammonium reineckate) to form ion associates between these reagents and daclatasvir in the aqueous system.

RESULTS

All proposed platforms were validated in line with recommendations of the international conference on harmonization producing satisfactory outcomes within the agreed boundaries.

CONCLUSION

The proposed platforms are green alternatives for routine rapid assay of daclatasvir at the cheapest cost because their results were observed to be nearly similar to those of the reported platform. Moreover, the suggested spectrophotometric platform's sensitivity can be employed for investigating daclatasvir bioequivalence.

Analytical approaches for determination of COVID-19 candidate drugs in human biological matrices

Since the outbreak of the COVID-19 pandemic, the use of antiviral and other available drugs has been considered to combat or reduce the clinical symptoms of patients. In this regard, it would be necessary to choose sensitive and selective analytical techniques for pharmacokinetic and pharmacodynamic studies, monitoring of drug concentration in biological fluids, and determination of the most appropriate dose to achieve the desired effect on the disease. In the present study, the analytical techniques based on spectroscopy and chromatography with different detectors for diagnosis and determination of candidate drugs in the treatment of COVID-19 in human biological fluids are reviewed during the period 2015-2022. Moreover, various sample preparation and extraction techniques, are being used for this purpose, such as protein precipitation (PP), solid-phase extraction (SPE), liquid-liquid extraction (LLE), and QuEChERS (quick, easy, cheap, effective, rugged, and safe) are investigated.

A Review on Analytical Strategies for the Assessment of Recently Approved Direct Acting Antiviral Drugs

Human beings are in dire need of developing an efficient treatment against fierce viruses like hepatitis C virus (HCV) and Coronavirus (COVID-19). These viruses have already caused the death of over two million people all over the world. Therefore, over the last years, many direct-acting antiviral drugs (DAADs) were developed targeting nonstructural proteins of these two viruses. Among these DAADs, several drugs were found more effective and safer than the others as sofosbuvir, ledipasvir, grazoprevir, glecaprevir, voxilaprevir, velpatasvir, elbasvir, pibrentasvir and remdesivir. The last one is indicated for COVID-19, while the rest are indicated for HCV treatment. Due to the valuable impact of these DAADs, larger number of analytical methods were required to meet the needs of the clinical studies. Therefore, this review will highlight the current approaches, published in the period between 2017 to present, dealing with the determination of these drugs in two different matrices: pharmaceuticals and biological fluids with the challenges of analyzing these drugs either alone, with other drugs, in presence of interferences (pharmaceutical excipients or endogenous plasma components) or in presence of matrix impurities, degradation products and metabolites. These approaches include spectroscopic, chromatographic, capillary electrophoretic, voltametric and nuclear magnetic resonance methods that have been reported during this period. Moreover, the analytical instrumentation and methods used in determination of these DAADs will be illustrated in tabulated forms.

Analytical Methods for Determination of Antiviral Drugs in Different Matrices: Recent Advances and Trends

Viruses are the main pathogenic substances that cause severe diseases in humans and other living things. They are among the most common microorganisms, and consequently, antiviral drugs have emerged to prevent and treat viral infections. Antiviral drugs are an essential drug group considering their prescription and consumption rates for different diseases and indications. Therefore, it is crucial to develop accurate and precise analytical methods to detect antiviral drugs in various matrices. Chromatographic techniques are used frequently for the quantification purpose since they allow simultaneous determination of antivirals. Electrochemical methods have also gained importance since the analysis can be performed quickly without the need for pretreatment. Spectrophotometric and spectrofluorimetric methods are used because they are simple, inexpensive, and less time-consuming methods. The purpose of this review is to present an overview of the analysis of currently used antiviral drugs from 2010 to 2021. Since studies on antiviral drugs are numerous, selected publications were reviewed in this article. The analysis of antiviral drugs was divided into three main groups: chromatographic, spectrometric, and electrochemical methods which were applied to different matrices, including pharmaceutical, biological, and environmental samples.

Improved spectral resolution for the rapid simultaneous spectrophotometric determination of sofosbuvir and daclatasvir as anti hepatitis C virus drugs in pharmaceutical formulation and biological fluid using continuous wavelet and derivative transform

In this study, the simultaneous spectrophotometric estimation of Sofosbuvir (SOF) and Daclatasvir (DAC) in synthetic mixtures and tablet formulation in the presence of overlapping spectra was performed based on continuous wavelet transform (CWT) and derivative spectrophotometry (DS) methods without any separation process. The Coiflet (Coif2) and Daubechies (Db3) wavelet families with wavelength of 256 nm and 218 nm were obtained as the best families for the simultaneous determination of SOF and DAC, respectively. Also, the first derivative absorption spectra revealed the best results corresponding to the analysis of SOF and DAC at 237 nm and 291 nm, respectively. The ranges of limit of detection (LOD) and limit of quantitation (LOQ) related to the CWT and DS methods were 2.45 × 10^-3 to 0.5054 and 6.91 × 10^-3 to 0.6027, respectively. Mean recovery values of SOF and DAC in synthetic mixtures for CWT approach were 98.55%, 98.09% and in DS method were 98.78% and 95.83%, respectively. Real samples, including Sovodak tablet and urine was used for accurate simultaneous determination of the mentioned components. Analyzing Sovodak tablet was implemented using high-performance liquid chromatography (HPLC) as a reference method that the results were near to the CWT and DS methods. In order to investigate the existence of significant differences between the methods, analysis of variance (ANOVA) test at the 95% confidence level was performed but no significant differences were observed. In addition, the amounts of SOF and DAC in the complex matrix of biological sample were well predicted by the proposed methods.

Characterization of astragaloside I-IV based on the separation of HPTLC from Pleurotus ostreatus cultivated with Astragalus

In this study, total saponins were extracted from Pleurotus ostreatus cultivated with Astragalus as one of organic culture substrates. High Performance Thin Layer Chromatography (HPTLC) assay showed total saponins could be separated effectively, and four kinds of spots were identified as AG I, AG II, AG III, and AG IV, respectively. FTIR spectra based on HPTLC separation assay showed the saponin characteristic groups including -OH, C-H, C=O, and the glycoside linkaged to sapogenin group C-O-C, suggesting the four kinds of spots belonged to cycloartane-type triterpene saponins. The primary mass spectra of precursor ion (HPTLC-ESI-MS) assay further proved the main composition of four kinds of spots was AG I-IV, respectively. Physical properties, including the detection of specific rotation and melting point, revealed the separation of high-purity saponin monomer by HPTLC. HPTLC-dual wavelength spectrodensitometric method detection showed that content of astragaloside I-IV was ranged from 0.2 to 0.5 mg/g, and the total astragalosides contents attained to 1.397 mg/g, indicating P. ostreatus could bioaccumulate astragalosides from Astragalus. These results demonstrated the characterization of astragalosides based on the separation of HPTLC was effective, and supported to consider astragalosides-enriched P. ostreatus as functional edible fungus for food and medical applications. PRACTICAL APPLICATION: Currently, the consumption of enriched foods has become common and continues to increase due to urgent demanding for foods with high nutritional value. Pleurotus ostreatus is a functional edible fungus, which not only can produce secondary metabolites, but can enrich bioactive ingredients. Astragalosides have a wide range of biological activities, especially currently being tested as cardioprotective agent. In this study, P. ostreatus was cultivated through adding Astragalus into culture substrates, which realized massive enrichment of astragalosides. Astragalosides-enriched P. ostreatus as functional edible fungus could be extensively used in food and medical areas, especially for the prevention of cardiovascular diseases.

Quantitative determination of canagliflozin in human plasma samples using a validated HPTLC method and its application to a pharmacokinetic study in rats

Canagliflozin (CNZ) is the first sodium-glucose co-transporter-2 inhibitor approved for treatment of type 2 diabetes mellitus. In the proposed work, a sensitive, rapid and validated high-performance thin-layer chromatography (HPTLC) method was established for the estimation of CNZ in human plasma for the first time. HPTLC analysis of CNZ and internal standard (sildenafil) was performed on glass coated silica gel 60 F₂₅₄ HPTLC plates using a binary mixture of chloroform-methanol 9:1 (%, v/v) as the mobile phase. Densitometric detection was done at 295 nm. Retardation factor values were obtained as 0.22 and 0.52 for the CNZ and the IS, respectively. The linearity range of CNZ was obtained as 200-3,200 ng/ml. A simple protein precipitation method was used for the extraction of analyte from plasma using methanol. The proposed HPTLC technique was validated for linearity, accuracy, precision and robustness. The proposed HPTLC technique was successfully utilized for the assessment of pharmacokinetic profile of CNZ in rats after oral administration. After oral administration, the peak plasma concentration of CNZ was obtained as 1458.01 ng/ml in 2 h. The proposed HPTLC method could be applied to the study of the pharmacokinetic profile of pharmaceutical formulations containing CNZ.

Simple and Accurate HPTLC-Densitometric Method for Quantification of Delafloxacin (A Novel Fluoroquinolone Antibiotic) in Plasma Samples: Application to Pharmacokinetic Study in Rats

Delafloxacin (DLX) is a recently-approved fluoroquinolone antibiotic, which is recommended for the treatment of "acute bacterial skin and skin structure infections". A thorough literature survey revealed only a single published method for the estimation of DLX using UPLC-MS/MS technique in biological samples. There is no high-performance thin-layer chromatography (HPTLC) method has been reported for the estimation of DLX in dosage forms and/or biological samples. Therefore, a selective, sensitive, rapid and validated HPTLC-densitometry technique has been used for the estimation of DLX in human plasma for the first time. HPTLC quantification of DLX and internal standard (IS; gatifloxacin) was carried out on glass coated silica gel 60 F254 HPTLC plates using the ternary mixture of ethyl acetate:methanol:ammonia solution 5:4:2 (%, v/v/v) as the mobile phase. Densitometric detection was done at 344 nm. The Rf values were recorded as 0.43 and 0.27 for the DLX and the IS, respectively. The linearity range of DLX was obtained as 16-400 ng/band. A simple protein precipitation method was used for the extraction of analyte from plasma using methanol. The proposed HPTLC technique was validated for "linearity, accuracy, precision, and robustness". The proposed HPTLC technique was successfully utilized for the assessment of pharmacokinetic profile of DLX in rats after oral administration. After oral administration, the peak plasma concentration of DLX was obtained as 194.19 ng/ml in 1 h. The proposed HPTLC method could be applied in study of pharmacokinetic profile and therapeutic drug monitoring of DLX in clinical practice.

Modification of N,S co-doped graphene quantum dots with p-aminothiophenol-functionalized gold nanoparticles for molecular imprint-based voltammetric determination of the antiviral drug sofosbuvir

A molecularly imprinted polymer (MIP) was developed for the electrochemical determination of the antiviral drug sofosbuvir (SOF). The MIP was obtained by polymerization of p-aminothiophenol (p-ATP) on N,S co-doped graphene quantum dots (N,S@GQDs) in the presence of gold nanoparticles to form gold-sulfur covalent network. The presence of quantum dots improves the electron transfer rate, enhances surface activity and amplifies the signal. The nanocomposites were characterized by FTIR, TEM, EDX, and SEM. The electrochemical performance of the electrode was investigated by differential pulse voltammetry and cyclic voltammetry. The sensor uses hexacyanoferrate as the redox probe and is best operated at a potential of around 0.36 V vs. Ag/AgCl. It has a linear response over the concentration range of 1-400 nM SOF, with a detection limit of 0.36 nM. Other features include high selectivity, good reproducibility and temporal stability. The sensor was applied to the determination of SOF in spiked human plasma. Graphical abstract Novel sofosbuvir imprinted p-ATP polymer was synthesized by the aid of gold nanoparticles on N,S co-doped graphene quantum dots as a good conductive support. The imprinted polymer was used for detection of sofosbuvir in real samples by using the ferri/ferrocyanide redox probe.

New, simple and sensitive HPTLC method for simultaneous determination of anti-hepatitis C sofosbuvir and ledipasvir in rabbit plasma

Sofosbuvir (SOF) and ledipasvir (LDS) represent anti-hepatitis C binary mixture. Herein, a fast high-performance thin-layer chromatography (HPTLC) method was developed, validated and applied for simultaneous determination of SOF and LDS in biological matrix. An innovative strategy was designed which based on coupling dual wavelength detection with HPTLC. This strategy enabled sensitive, specific, high sample throughput and cost-effective determination of the SOF-LDS binary mixture. The developed HPTLC procedure is based on a simple liquid-liquid extraction, enrichment of the analytes and subsequent separation with UV detection. Separations were performed on HPTLC silica gel 60 F₂₅₄ aluminum plates with a mobile phase consisting of ethyl acetate-glacial acetic acid (100:5, v/v). The R_f values for SOF and LDS were 0.62 and 0.30, respectively. Dual wavelength scanning was carried out in the absorbance mode at 265 and 327 nm for SOF and LDS, respectively. The linear ranges were 40-640 and 9-144 ng/band for SOF and LDS, respectively with correlation coefficients of 0.9998. The detection limits were 10.61 and 2.54 ng/band and the quantitation limits were 32.14 and 7.70 ng/band for SOF and LDS, respectively indicating high sensitivity of the proposed method. Consequently, this permits in vitro and in vivo application of the proposed method in rabbit plasma with good percentage recovery (95.68-103.26%). Validation parameters were assessed according to ICH guidelines. The proposed method represents a simple, high sample throughput and economic alternative to the already existing more complicated reported LC-MS/MS techniques. The method would afford an efficient tool for therapeutic drug monitoring and bioavailability studies of SOF and LDS.

Simultaneous quantitation of two direct acting hepatitis C antivirals (sofosbuvir and daclatasvir) by an HPLC-UV method designated for their pharmacokinetic study in rabbits

Sofosbuvir (SOF) and daclatasvir (DCS) are novel, recently developed direct acting antiviral agents characterized by potent anti-hepatitis C virus action. A fast and efficient HPLC-UV method was developed, validated and applied for simultaneous determination of SOF and DCS in pharmaceutical formulations and biological fluids based on coupling liquid-liquid extraction with ultrasound and dual wavelength detection at λ_max; 260 and 313 nm for SOF and DCS, respectively. This approach provided simple, sensitive, specific and cost-effective determination of the SOF-DCS mixture with good recoveries of the analytes from plasma. Analytes were separated within 7 min on C₁₈ analytical column with acetonitrile-10 mM acetate buffer of pH 5.0 at a flow rate of 1.0 mL min^-1. The linear ranges were 1-20 μg mL^-1 for SOF and 0.6-6 μg mL^-1 for DCS with correlation coefficients ≥0.9995. The detection limits in spiked rabbit plasma were 0.20 and 0.19 μg mL^-1 for SOF and DCS, respectively. The method was validated according to ICH and US-FDA guidelines. Finally, the method was successfully applied for simultaneous pharmacokinetic studies of SOF and DCS in rabbits using rofecoxib as internal standard.