An eco-friendly multi-analyte high-performance thin layer chromatographic densitometric determination of amoxicillin, metronidazole, and famotidine in their ternary mixtures and simulated gastric juice: A promising protocol for eradicating Helicobacter pylori.

Gastrointestinal tract disorders constitute a heavy burden to healthcare providers. To eradicate Helicobacter pylori infection, different triple therapy protocols have been proposed. Among which are combinations of proton pump inhibitors (e.g., omeprazole), histamine-2 receptor antagonists (e.g., famotidine), along with antibiotics (e.g., amoxicillin). In this work, a sensitive and accurate high-performance thin-layer chromatographic method was developed for the simultaneous determination of amoxicillin, metronidazole, and famotidine in bulk powder and laboratory-prepared combined-tablet mixtures. Complete separation of the cited compounds was achieved using pre-coated silica gel plates with a mixture of methanol:chloroform:toluene:water:glacial acetic acid (5:2:1.5:0.5:0.1 v/v/v/v/v) as the mobile phase. The method was fully validated as per the international conference of harmonization guidelines. Good linearity, a correlation coefficient of 0.9991, was obtained in the concentration ranges 0.1-1.6 µg/band (amoxicillin), 0.1-0.9 µg/band (metronidazole), and 0.1-0.9 µg/band (famotidine). Since the method allowed the determination of the three compounds in combined tablets with a high degree of selectivity, accuracy, precision, with cost-effectiveness, it could be used for regular quality control. Moreover, the applicability of the proposed method was extended to the determination of the ternary mixture in simulated gastric juice. Method greenness was assessed using different green metrics.

In-depth investigation of the Silymarin effect on the pharmacokinetic parameters of sofosbuvir, GS-331007 and ledipasvir in rat plasma using LC-MS.

The use of complementary medicine (CMD) for liver support in Hepatitis C virus (HCV) patients sometimes coincides with the administration of oral antiviral drugs to eradicate the virus. This calls for a deep investigation of CMD effects on the pharmacokinetic parameters of these drugs to ensure their safety and efficacy. Silymarin (SLY), as a CMD, was selected to be given orally to healthy male rats with sofosbuvir (SFB) and ledipasvir (LED), a common regimen in HCV treatment. A new and sensitive LC-MS method was validated for the bioassay of SLY, LED, SFB and its inactive metabolite, GS-331007, in spiked plasma with lower limits of quantitation of 10, 1, 4 and 10 ng/ml, respectively. Moreover, the method was further applied to conduct a full pharmacokinetic profile of SFB, GS-331007 and ledipasvir with and without SLY. It was found that co-administration of SLY may expose the patient to unplanned high serum concentrations of SFB and LED. This could be accompanied by a decrease in SFB efficacy, potentially leading to therapeutic failure and the emergence of viral resistance.

LC-MS bioanalysis of targeted nasal galantamine bound chitosan nanoparticles in rats' brain homogenate and plasma.

Validated LC-MS method for the direct quantitative analysis of galantamine (acetylcholinesterase inhibitor) was developed in rat cerebrospinal fluid and brain homogenate besides rat plasma, utilizing structurally close nalbuphine as an internal standard. After a simple protein precipitation step, samples are separated on 2-µm C18 column kept at 40 °C, using isocratic flow of 80% methanol in pH 9.5 ammonium formate buffer, and retention times were about 1.8 and 2.9 min for galantamine and nalbuphine, respectively. Mass detection with electrospray ionization (ESI) and positive polarity was able to detect 0.2 ng mL-1 galantamine using single ion monitoring mode (SIM) at m/z 288 for galantamine and m/z 358 for nalbuphine. The method showed linearity within the range of 0.5 - 300 ng mL-1. The proposed method was validated according to FDA guidelines. Trueness and precision showed acceptable values at all quality control levels, and recoveries were within 85.6 - 114.3% in all matrices at all runs and with relative standard deviations within 0.2 - 12.4%. The method was used to study in vivo brain uptake and pharmacokinetics of galantamine from brain homogenate and plasma samples following the administration of nasal galantamine-bound chitosan nanoparticles compared to oral and nasal galantamine solutions, in scopolamine-induced Alzheimer's disease rat model.

Box-Behnken response surface modeling assisted enantiomeric resolution of some racemic ß-blockers using HPTLC and ß-cyclodextrin as chiral mobile phase additive: Application to check the enantiomeric purity of betaxolol.

Stereospecific separation method of (±) betaxolol, (±) carvedilol, and (±) sotalol using High Performance Thin Layer Chromatography (HPTLC) and ß-cyclodextrin as chiral selector has been developed and validated. The Box-Behnken surface response design was selected for optimizing the operating variables based on 15 trials design. The optimized method involves separation on Fluka HPTLC silica gel plates 60 F254 (20 × 10 cm) using acetonitrile-methanol-acetic acid-water (3.4:3.6:0.18:1 v/v) as a mobile phase containing 0.57 mM ß-cyclodextrin. Densitometric measurements were made at 220 nm for betaxolol and sotalol or at 245 nm for carvedilol. Maximum separation of the enantiomers of the three drugs was obtained by optimizing concentration of chiral selector, the mobile phase composition including acetonitrile amount in the organic part of the mobile phase and the volume of acetic acid added. The proposed method enables estimation of (-) and (+) enantiomers of betaxolol in drug substance and in various pharmaceuticals. The detection limit of betaxolol was 0.15 and 0.13 µg band-1 for (-) and (+) enantiomers, respectively. The detection limits were found to be 0.2 and 0.3 µg band-1 for carvedilol and sotalol, respectively, as racemate. In addition, the proposed method was applied in checking the enantiomeric purity of (-) BET in the presence of (+) BET at 1% level where the inactive (+) enantiomer was quantified with good accuracy and precision at 1% level in the active (-) enantiomer.

Least median of squares and iteratively re-weighted least squares as robust linear regression methods for fluorimetric determination of α-lipoic acid in capsules in ideal and non-ideal cases of linearity.

This study outlines two robust regression approaches, namely least median of squares (LMS) and iteratively re-weighted least squares (IRLS) to investigate their application in instrument analysis of nutraceuticals (that is, fluorescence quenching of merbromin reagent upon lipoic acid addition). These robust regression methods were used to calculate calibration data from the fluorescence quenching reaction (∆F and F-ratio) under ideal or non-ideal linearity conditions. For each condition, data were treated using three regression fittings: Ordinary Least Squares (OLS), LMS and IRLS. Assessment of linearity, limits of detection (LOD) and quantitation (LOQ), accuracy and precision were carefully studied for each condition. LMS and IRLS regression line fittings showed significant improvement in correlation coefficients and all regression parameters for both methods and both conditions. In the ideal linearity condition, the intercept and slope changed insignificantly, but a dramatic change was observed for the non-ideal condition and linearity intercept. Under both linearity conditions, LOD and LOQ values after the robust regression line fitting of data were lower than those obtained before data treatment. The results obtained after statistical treatment indicated that the linearity ranges for drug determination could be expanded to lower limits of quantitation by enhancing the regression equation parameters after data treatment. Analysis results for lipoic acid in capsules, using both fluorimetric methods, treated by parametric OLS and after treatment by robust LMS and IRLS were compared for both linearity conditions.

First derivative emission spectrofluorimetric method for the determination of LCZ696, a newly approved FDA supramolecular complex of valsartan and sacubitril in tablets.

LCZ696 (sacubitril/valsartan, Entresto™) is a therapy lately approved by United States Food and Drug Administration (US FDA) as a heart failure therapy. It is claimed to decrease the mortality rate and hospitalization for patients with chronic heart failure. This study is considered as the first report to investigate the fluorimetric behavior of sacubitril in addition to pursuing all the different conditions that may affect its fluorescence. Various conditions were studied, for example studying the effects of organized media, solvents and pH, which may affect the fluorescence behavior of sacubitril. For the simultaneous determination of the newly approved supramolecular complex of valsartan (VAL) and sacubitril (SAC) in their tablets, a sensitive and simple first derivative spectrofluorimetric method was developed. The method involved the measurement of native fluorescence at 416 nm and 314 nm (λex 249 nm) for VAL and SAC, respectively. The first (D1) derivative technique was applied to the emission data to resolve a partial overlap that appeared in their emission spectra. The proposed method was successfully applied for the assay of the two drugs in their supramolecular complex LCZ696 with no interference from common pharmaceutical additives. International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) guidelines were followed in order to validate the proposed method.

Derivative emission spectrofluorimetry: Application to the analysis of newly approved FDA combination of ibuprofen and famotidine in tablets.

A new combination of ibuprofen (NSAID) and famotidine (H2 receptor antagonist) was recently approved by the FDA. It was formulated to relief pain while decreasing the risk of ulceration, which is a common problem for patients receiving NSAID. A rapid and simple derivative emission spectrofluorimetric method is proposed for the simultaneous analysis of this combination in their pharmaceutical preparation. The method is based upon measurement of the native fluorescence intensity of the two drugs at λex = 233 nm in acetonitrile. The emission data were differentiated using the first (D1) derivative technique. The plots of derivative fluorescence intensity versus concentration were rectilinear over a range of 2-35 and 0.4-8 µg/mL for both ibuprofen (IBU) and famotidine (FAM), respectively. The method was sensitive as the limits of detection were 0.51 and 0.12 µg/mL and limits of quantitation were 1.70 and 0.39 µg/mL, for IBU and FAM respectively. The proposed derivative emission spectrofluorimetric method was successfully applied for the determination of the two drugs in their synthetic mixtures and tablets with good accuracy and precision. The proposed method was validated as per ICH guidelines.

Convolution of emission derivative ratio curves of closely related fluorescent reaction products using discrete fourier functions and non-parametric linear regression method.

A spectrofluorimetric method was used for the estimation of closely related fluorescent reaction products, Fluoxetine and Olanzapine, in their mixture after derivatization of both drugs using 4-chloro-7- nitrobenzo - 2 -oxa-1,3 - diazole (NBD-Cl) in borate buffered medium (pH 9.5) to form highly fluorescent products. The method based on the use of first and second derivative ratio of the emission data along with their convolution using 8-points sin x i or cos x i polynomials (discrete Fourier functions). The proposed method facilitates their simultaneous determination despite the presence of a minor component (Olanzapine) and strong overlapped spectra of the two NBD-Cl fluorescent products of fluoxetine and olanzapine. The accurate and precise estimation of the minor component was achieved after the convolution of the derivative ratio curves. Moreover, the obtained data were subjected to non-parametric linear regression analysis (Theil's method). The work combines the advantages of convolution of derivative ratio curves using discrete Fourier functions together with the reliability and efficacy of the non-parametric analysis of data.

An eco-friendly liquid chromatographic analysis of the triple therapy protocol of amoxicillin, metronidazole and vonoprazan for H. Pylori eradication: application to combined dosage forms and simulated gastric fluid.

Helicobacter pylori has a big sway when peptic ulcers are concerned. For its eradication, different protocols have been approved. Among which, the tripartite therapy protocol which embraces vonoprazan as potassium competitive acid blocker in combination with amoxicillin and metronidazole as antibiotics. An environmentally benign HPLC method is addressed in order to simultaneously determine amoxicillin (AMX), metronidazole (MET) and vonoprazan (VPZ) in bulk powder and combined tablet mixture. Full separation of AMX, MET and VPZ is accomplished using C8 column, and a gradient mobile phase system, composed of methanol and phosphate buffer of a pH value of 5. Fine linearity in the concentration ranges 50-600 µg mL-1 amoxicillin, 50-400 µg mL-1 metronidazole and 10-100 µg mL-1 vonoprazan was denoted by the high correlation coefficient (0.9999). The method accuracy and precision are confirmed upon analyzing AMX, MET and VPZ triple therapy not only in their synthetic mixtures and combined tablet mixtures but also in their combined tablet mixtures in simulated gastric fluid. AMX, MET and VPZ triple therapy could be routinely analyzed in QC labs, in case of being co-formulated, using the presented method. Three different assessment tools were adopted revealing the benign environmental impact of presented method.

Bioanalytical HPLC method with fluorescence detector for determination of Entresto™ when co-administered with ibuprofen and fexofenadine: a pharmacokinetic study.

Entresto™ (LCZ696) has been approved globally for heart failure management. However, its lifelong use alongside over-the-counter (OTC) drugs like ibuprofen (IBU) and fexofenadine (FEX) necessitates an in-depth investigation of potential pharmacokinetic interactions, as they share the same metabolic and elimination pathways. This study aimed to develop a bioanalytical HPLC method with a fluorescence detector (FLD) to quantify LCZ696 analytes (valsartan, VAL; sacubitril, SAC; and sacubitril active metabolite, LBQ657) in rat plasma. Additionally, an in vivo study was performed to investigate the pharmacokinetic interactions of LCZ696 with IBU and FEX. Utilizing HPLC with a gradient-mode mobile phase of acetonitrile and 0.025 M phosphate buffer (pH 3), the study demonstrated a significant increase in the bioavailability of LCZ696 analytes (VAL and LBQ657) when co-administered with IBU (C max 0.23 ± 0.07 and 0.53 ± 0.21 µg mL-1, respectively) compared to the control (0.17 ± 0.03 and 0.33 ± 0.14 µg mL-1). A more significant increase in C max was noticed with FEX (0.38 ± 0.01 and 0.77 ± 0.18 µg mL-1, respectively). Moreover, a decrease in the clearance (Cl/F) of VAL and LBQ657 was observed (18.05 ± 1.94 and 12.42 ± 2.97 L h-1 kg, respectively) with a more pronounced effect in the case of FEX (30.87 ± 4.29 and 33.14 ± 9.57 L h-1 kg, respectively) compared to the control (49.99 ± 7.31 and 51.19 ± 9.12 L h-1 kg, respectively). In conclusion, our study underscores the importance of cautious administration and appropriate dose spacing of IBU and FEX in patients treated with LCZ696 to prevent elevated serum concentrations and potential toxicity. The novelty of this work lies in its dual contribution: developing a highly sensitive HPLC-FLD method and comprehensively elucidating significant pharmacokinetic interactions between LCZ696 and common OTC drugs.

Simultaneous determination of montelukast and fexofenadine using Fourier transform convolution emission data under non- parametric linear regression method.

New hybrid chemometric method has been applied to the emission response data. It deals with convolution of emission data using 8-points sin xi polynomials (discrete Fourier functions) after the derivative treatment of these emission data. This new application was used for the simultaneous determination of Fexofenadine and Montelukast in bulk and pharmaceutical preparation. It was found beneficial in the resolution of partially overlapping emission spectra of this mixture. The application of this chemometric method was found beneficial in eliminating different types of interferences common in spectrofluorimetry such as overlapping emission spectra and self- quenching. Not only this chemometric approache was applied to the emission data but also the obtained data were subjected to non-parametric linear regression analysis (Theil's method). The presented work compares the application of Theil's method in handling the response data, with the least-squares parametric regression method, which is considered the de facto standard method used for regression. So this work combines the advantages of derivative and convolution using discrete Fourier function together with the reliability and efficacy of the non-parametric analysis of data. Theil's method was found to be superior to the method of least squares as it could effectively circumvent any outlier data points.

Comparative study of some robust statistical methods: weighted, parametric, and nonparametric linear regression of HPLC convoluted peak responses using internal standard method in drug bioavailability studies.

This manuscript discusses the application and the comparison between three statistical regression methods for handling data: parametric, nonparametric, and weighted regression (WR). These data were obtained from different chemometric methods applied to the high-performance liquid chromatography response data using the internal standard method. This was performed on a model drug Acyclovir which was analyzed in human plasma with the use of ganciclovir as internal standard. In vivo study was also performed. Derivative treatment of chromatographic response ratio data was followed by convolution of the resulting derivative curves using 8-points sin x i polynomials (discrete Fourier functions). This work studies and also compares the application of WR method and Theil's method, a nonparametric regression (NPR) method with the least squares parametric regression (LSPR) method, which is considered the de facto standard method used for regression. When the assumption of homoscedasticity is not met for analytical data, a simple and effective way to counteract the great influence of the high concentrations on the fitted regression line is to use WR method. WR was found to be superior to the method of LSPR as the former assumes that the y-direction error in the calibration curve will increase as x increases. Theil's NPR method was also found to be superior to the method of LSPR as the former assumes that errors could occur in both x- and y-directions and that might not be normally distributed. Most of the results showed a significant improvement in the precision and accuracy on applying WR and NPR methods relative to LSPR.

Development and optimization of a capillary zone electrophoresis technique for simultaneous determination of miconazole nitrate and hydrocortisone acetate in a cream pharmaceutical formulation.

A simple, fast, inexpensive, and reliable capillary zone electrophoresis (CZE) method for the determination of a mixture of miconazole nitrate (MCZ) and hydrocortisone acetate (HCZ) in a cream formulation has been developed and validated. Optimum conditions were sodium dihydrogen phosphate buffer (50 mM, pH 4) and 30 kV applied voltage in a 85 cm x 75 pm id capillary. Direct UV detection at 230 nm led to adequate sensitivity without interference from the sample excipients. MCZ and HCZ migrated in approximately 165 and 415 s, respectively. The analytical curves had a coefficient of correlation, r, of 0.9999 and 0.9996 for MCZ and HCZ, respectively. The LOD and LOQ were 0.28 and 0.93 microg/mL for MCZ and 0.38 and 1.27 microg/mL for HCZ, respectively. Thus, excellent accuracy and precision were obtained. Recoveries varied from 98 to 102%, and intraday and interday precision, calculated as the RSD, were less than 2.0% for each drug. The proposed CZE method displayed advantageous performance characteristics and can be considered suitable for QC of the MCZ and HCZ cream formulation.

Green and white MEKC for determination of different anti-diabetic binary mixtures and their triple-combo pill.

The work introduces green and white sustainable micellar electrokinetic chromatography (MEKC) procedure that could analyze therapeutically related drugs, empagliflozin (EMP), linagliptin (LIN) and metformin (MET) which are antidiabetic drugs with different mechanism of action, in their different pharmaceutical combinations. The method not only comply with the green analytical concepts, but also it is in line with sustainable analytical concepts as it is economic by applying the same operating conditions to analyze different pharmaceuticals in quality control (QC) labs which is a crucial step in QC labs and research centers to save time, effort, and money. Moreover, the method functionality regarding its scope with its achieved levels of accuracy, precision, low detection, and quantitation limits is tested using white assessment tool and compared with reported methods. The proposed MEKC coupled with a diode array detector (DAD) has been developed and validated for micro estimation of EMP and LIN in their low critical concentrations with MET in a ratio of (EMP: MET, 1:40) and (LIN: MET, 1:200). Separation was achieved within 6 min using fused silica capillary (40 cm × 50 µm id) using 20 mM Tris buffer (pH 10) in presence of 50 mM sodium dodecyl sulphate and 10% v/v methanol. The concentration ranges of the studied anti-diabetic drugs were 10-500, 10-100 and 2.5-100 µg. mL-1 for MET, EMP and LIN, respectively. The developed method is the first MEKC for concurrent determination of EMP, LIN and MET with high separation efficiency, low solvent consumption and regard as an easy green and white analytical tool. Moreover, Greenness and whiteness assessment were done via the most widely used Analytical Eco-Scale, the innovative AGREE tool and the RGB 12 algorithm.

Recent Analytical Methodologies for the Determination of Omeprazole and/or Its Active Isomer Esomeprazole in Different Matrices: A Critical Review.

The presented work comprehensively discusses omeprazole (OMZ) and its S-active isomer (esomeprazole, ESZ) different methods of analysis indexed in Web of science, Scopus and Pub-med from 2016 till now. Chromatographic methods with different detectors each to fulfill the aim of the analysis were discussed. These chromatographic methods aimed to analyze OMZ and ESZ in biological fluids in presence of other drugs and metabolites for studying drug kinetics or drug-drug interaction and enzyme polymorphism. Moreover, in-vitro chromatographic methods were discussed for analyzing OMZ and ESZ in pharmaceuticals alone or in presence of other drugs. In addition, different chiral chromatographic methods separating the two enantiomers of OMZ (R-OMZ and ESZ) alone or with other chiral drugs or chiral impurities have been thoroughly discussed where no previous reviews have dealt with the chiral separation methods for OMZ and ESZ. Also, environmental analysis of OMZ and ESZ in various environmental samples was found as they are from the most popular drugs used and there is a high incidence that they may be present in wastewater. Moreover, reported spectroscopic and electrochemical methods for OMZ and ESZ analysis were discussed showing the structural features of OMZ/ESZ that lead to their successful analysis using spectroscopy and electrochemistry. Finally, the important figures of merit of all the discussed articles are shown in comprehensive tables and the article comprises 4 sections (chromatographic, electrochemical, spectroscopic and miscellaneous methods) and 7 tables.

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.

HPLC/Fluorescence-Diode Array Detection for Rapid and Reliable Determination of Illegal Synthetic Drugs in Male Sexual Herbal and Honey Remedies: Comparative Study with UFLC-MS.

BACKGROUND: Nutraceuticals (NTCs), as honey and tablets with herbal extract are subjected to adulteration. OBJECTIVE: For NTCs claimed to enhance sexual performance, synthetic drugs (sildenafil, tadalafil, avanafil, vardenafil, and dapoxetine) are common adulterants, so they were selected to be simultaneously analyzed in the current study. Natural aphrodisiacs (icariin and yohimbine) are claimed to be present in many fake NTCs, so they were also included in the study. METHODS: In order to achieve the target of the current study, three liquid chromatographic methods with different unique detectors were developed and validated. RESULTS: High performance liquid chromatography (HPLC) with fluorescence detection enables rapid and reliable determination of natively fluorescent yohimbine, tadalafil vardenafil, and dapoxetine and it is the first report to analyze these compounds as adulterants in counterfeit NTC. Although the diode-array detector (DAD) enables the analysis of the seven adulterants, the fluorescence detector (FLD) shows better sensitivity and selectivity with lower LOQs and LODs. On the other hand, ultra-fast liquid chromatography-mass spectrometry (UFLC-MS) offers the advantages of peak identity confirmation, and it is of comparable sensitivity and selectivity to HPLC-FLD. CONCLUSION: One or more of these synthetic drugs were found in the analyzed NTCs while natural aphrodisiacs were absent. HIGHLIGHTS: Aphrodisiac nutraceuticals, NTCs, were analyzed for adulterants: five aphrodisiac synthetic drugs (adulterants) and two natural claimed aphrodisiacs. UFLC-MS and HPLC-DAD/FLD were compared for illicit NTCs analysis; all NTCs show the presence of synthetic aphrodisiacs and the absence of natural ones.

Recent Advances and Applications of Microfluidic Capillary Electrophoresis: A Comprehensive Review (2017-Mid 2019).

Microfluidic capillary electrophoresis (MCE) is the novel technique resulted from the CE mininaturization as planar separation and analysis device. This review presents and discusses various application fields of this advanced technology published in the period 2017 till mid-2019 in eight different sections including clinical, biological, single cell analysis, environmental, pharmaceuticals, food analysis, forensic and ion analysis. The need for miniaturization of CE and the consequence advantages achieved are also discussed including high-throughput, miniaturized detection, effective separation, portability and the need for micro- or even nano-volume of samples. Comprehensive tables for the MCE applications in the different studied fields are provided. Also, figure comparing the number of the published papers applying MCE in the eight discussed fields within the studied period is included. The future investigation should put into consideration the possibility of replacing conventional CE with the MCE after proper validation. Suitable validation parameters with their suitable accepted ranges should be tailored for analysis methods utilizing such unique technique (MCE).

HPLC with fluorescence detection for the bioanalysis and pharmacokinetic study of Doxorubicin and Prodigiosin loaded on eco-friendly casein nanomicelles in rat plasma.

A rapid, efficient, and sensitive liquid chromatographic assay hyphenated to fluorometric detector (HPLC-FLD) was developed and validated for the determination of doxorubicin (DXR) and prodigiosin (PDG) in rat plasma. The sample pre-treatment involves a protein precipitation with acetonitrile with satisfying extraction efficiency (98% and 85% for DXR and PDG, respectively). The chromatographic separation was accomplished using stationary phase: Agilent Zorbax Eclipse plus-C18 analytical column (250 × 4.6 mm, 5 µm) and gradient eluting mobile phase of ammonium acetate (pH = 3), acetonitrile and methanol with programmed fluorescence detection. As the proposed method has been validated, it was subsequently implemented to evaluate DXR and PDG loaded on novel eco-friendly Casein nano drug delivery system after intravenous injection in healthy rats. A comparative pharmacokinetics' study was carried out in rats for DXR in free form, DXR alone entrapped in the nanomicelle and DXR with PDG entrapped in the nano micelle. After testing the differences in pharmacokinetic parameters of the different formulations using ANOVA, the results showed insignificant differences among the tested parameters. This indicates that the presented nanomicelle delivery system has succeeded to incorporate PDG and DXR in a hydrophilic, safe, and potent formulation. This novel nanomicelle has negligible effect on the distribution and elimination of DXR.

Determination of Ibuprofen and Phenylephrine in Tablets by High-Performance Thin Layer Chromatography and in Plasma by High-Performance Liquid Chromatography with Diode Array Detection.

Two chromatographic methods (high performance thin layer chromatography (HPTLC) and high performance liquid chromatography-diode array detector (HPLC-DAD)), were addressed for the analysis of a mixture consisted of phenylephrine hydrochloride and ibuprofen in two forms bulk and their combined dosage form. This binary mixture is considered to be a challenging one as the two drugs differ greatly in their chemical and physical properties. Not only this affects their simultaneous analysis, but also hinders their simultaneous extraction from biological fluids as plasma. That is the reason the literature lacks any report for the simultaneous extraction and analysis of these drugs from biological fluids. The concentration ranges of both drugs were 0.1-2.5 µg/spot and 0.1-100 µg/mL by HPTLC and HPLC, respectively. Not only was the HPLC-DAD method applied to the investigated drugs determination in pharmaceutical preparations, but also in spiked human plasma. Extensive study was conducted to optimize their simultaneous extraction from plasma as it was a crucial step for the in vivo analysis. The results obtained by proposed methods and a reference one were statistically comparable by analysis of variance test. No significant difference was recorded between the mean percent levels determined by the proposed methods and the reference one.