A Novel Spectrofluorimetric Determination of Antazoline and Xylometazoline in their Ophthalmic Formulation; Green Approach and Evaluation.

A green developed spectrofluorimetric method has been applied for Antazoline (ANT) and Xylometazoline (XLO) determination in both pharmaceutical formulation and pure form. The developed method is synchronous spectrofluorimetry coupled with the second derivative mathematical tool for the determination of antazoline and xylometazoline in their dosage form. The developed method depends on reacting the cited drugs with dansyl chloride, a suitable derivatizing agent, to generate highly fluorescent derivatives. The products formed were measured at emission wavelengths; 703.0 and 712.0 nm after being excited at wavelengths; 350.0 and 355.0 nm for antazoline and xylometazoline, respectively. Synchronous spectrofluorimetry coupled with second derivative mathematical tool was developed and optimized using fluorescence data manager software generating second derivative peak amplitudes at 556.5 nm for antazoline and 598.0 nm for xylometazoline. Linear responses have been represented over a wide range of concentration 0.5-12.0 µg/mL for antazoline and 0.1-10.0 µg/mL for xylometazoline, correspondingly. Method validation was successfully applied. Additionally, statistical comparison of developed method with official ones has been carried out where no significant difference was found. Evaluation of the method's greenness was proven using several assessment tools. Indeed, the method developed is found to be precise, sensitive, and discriminating to assess the cited drugs for regular analysis.

A novel green spectrofluorimetric method for simultaneous determination of antazoline and tetryzoline in their ophthalmic formulation.

A novel spectrofluorimetric method has been developed for determination of antazoline (ANT) and tetryzoline (TET) in their pharmaceutical formulation. A combined application of synchronous spectrofluorimetry and second derivative mathematical treatment was developed. The proposed method depends on reacting the cited drugs with dansyl chloride (DNS-Cl) being a suitable derivatizing agent generating highly fluorescent derivatives measured at emission wavelengths of 703.0 and 642.0 nm after excitation wavelengths of 350.0 and 320.0 nm for ANT and TET, respectively. The joint use of synchronous spectrofluorimetry with second derivative mathematical treatment is for the first time to be developed and optimized in aid of using fluorescence data manager software generating second derivative peak amplitudes at 556.5 nm for ANT and 516.7 nm for TET. Linear responses have been represented over a wide range of concentration (0.5-12.0 µg/mL for ANT and 0.5-10.0 µg/mL for TET). Additionally, statistical comparison of the developed method with the official ones has been carried out where no significant difference was found. Additionally, greenness profile assessment was accomplished by means of four metric tools. Indeed, the method developed is found to be precise, sensitive, and discriminating to assess the cited drugs for regular analysis.

Molecular size distribution assessment of Haemophilus influenzae vaccine containing lactose by HPAEC-PAD and colorimetric assays.

Molecular size distribution of Haemophilus influenzae type b (Hib) conjugate vaccine is an important indicator for its immunogenicity and stability. Molecular size distribution was evaluated by High-Performance Protein Chromatography on Sepharose CL-4B column, and fractions were pooled. The use of high flow rate, incorporation of a calibration standard with the injected buffer and pooling method yielded a superior assay compared to conventional pharmacopeial method. The pools were analyzed for determination of distribution coefficient (KD) of 0.2 and 0.5 using two validated techniques: High Performance Anion Exchange Chromatography with pulsed amperometric detection (HPAEC-PAD) for ribitol determination and an optimized colorimetric assay for phosphorus determination. Linearity was achieved over range of 0.10-10.0 µg/mL and 1.0-8.0 µg/mL with LOD of 0.03 and 0.28 µg/mL for HPAEC and colorimetric assays, respectively. The developed assays were successfully applied in quality control monitoring of Hib conjugate vaccine. The optimized colorimetric method had shortened the analysis time to 25 min compared to 3.5 h for the European pharmacopeial assay by modifying the burning process. HPAEC stability results revealed 40% decrease in MSD after stressed storage conditions. The proposed assays offer a reliable and economic platform for monitoring the quality attributes of Hib for biopharma industry.

A novel stability-indicating HPLC-DAD method for determination of favipiravir, a potential antiviral drug for COVID-19 treatment; application to degradation kinetic studies and in-vitro dissolution profiling.

Modern pharmaceutical analysis is paying a lot of attention to the stability of novel drug formulations as well as establishment of suitable stability-indicating approaches. In the current work, a comprehensive stability-indicating HPLC-DAD method has been developed and validated for determination of favipiravir (FAV) which is a novel and emerging antiviral option in COVID-19 treatment. The stability of FAV was examined under different stress conditions. FAV was found to be susceptible to acid, base hydrolysis and oxidative degradation. Structure elucidation of the forced degradation products was carried out using mass spectrometry (MS) operated in electrospray ionization mode. Effective separation of FAV and its induced degradation products was achieved using isocratic elution mode on Zorbax C18 column maintained at 30 °C. The mobile phase used was comprised of 25.0 mM phosphate buffer (pH 3.5 ± 0.05) containing 0.1% (w/v) heptane sulphonic acid sodium salt-methanol-acetonitrile (62:28:10, by volume), delivered at flow rate of 1.0 mL/min. The diode array detector signal for FAV was monitored at 321.0 nm over a concentration range of 6.25-250.00 µg/mL. The potential mechanisms for generation of degradation products were postulated through comparison of MS1 fragmentation pattern of FAV and its degradation products. Moreover, the proposed method was also extended to study the degradation kinetics. Additionally, dissolution profiling of FAV in different media was monitored. Clearly, the suggested approach is accurate, reliable, time-saving, and cost-effective. As a result, it may be utilized for regular quality control and stability assessment of FAV in its tablet dosage form.

Stability assessment of tamsulosin and tadalafil co-formulated in capsules by two validated chromatographic methods.

The advent of a new pharmaceutical formulation evokes the need for examining the chemical stability of their constituents and establishing proper stability-indicating methods. Herein, the stability of the newly co-formulated Tamsulosin and Tadalafil were examined under different stress conditions. The acidic degradation of Tamsulosin yielded its sulfonated derivative, while Tadalafil was susceptible to both acidic and basic degradation. Two stability-indicating chromatographic methods, namely; high-performance thin-layer chromatography and high-performance liquid chromatography, have been developed. Significant high-performance thin-layer chromatography-fractionation could be achieved by utilizing a stationary phase of silica gel 60 F254 and a mobile phase composed of ethyl acetate/toluene/methanol/ammonia (4:2:4:0.6, by volumes) with densitometric recording at 280 nm over a concentration range of 0.5-25 µg/band for both drugs. The HPLC-separation could be reached on XBridge® C18 column isocraticaly by using a mobile phase having acetonitrile/phosphate buffer, pH 6.0 (45:55, v/v) pumped at a flow rate of 1.7 mL/min and applying diode array ultraviolet-detection at 210 nm over a linearity range of 3-70 µg/mL for each drug. Specificity of the two methods was additionally assured via peak purity assessment. Moreover, the methods were distinctly exploited for evaluating the drugs' stability in accelerated stability-studied samples of Tamplus® capsules.

Chaotropic salts impact in HPLC approaches for simultaneous analysis of hydrophilic and lipophilic drugs.

Simultaneous determination of drugs with different physicochemical properties necessitates thorough research and careful selection of high-performance liquid chromatography conditions. In the present study, various concepts of high-performance liquid chromatography method development for this aim have been discussed. Moreover, the work was motivated by the advantages of utilizing different chaotropic anions as a new promising approach to overcome the limitations of ion-pairing agents commonly used for this purpose. Based on log P values, atorvastatin (log P = 6.36) and lisinopril (log P = -1.22) were chosen as representative examples for lipophilic and hydrophilic drugs, respectively. Several simple, economic, fast, and reliable high-performance liquid chromatography methods were developed for their simultaneous analysis and are presented in a comparative manner, highlighting their advantages and limitations. Peak elution profile showed satisfying retentions and resolution about 3. Photo-diode array calculations were exploited for identifying the molecules by their ultra-violet spectra and peak purity, calculated and presented as rectangular-shaped ratio grams. The linearity check showed excellent results and satisfactory system suitability parameters of both peaks. This confirms the investigation results and conclusions for the influence of the chaotropic salts on N-containing molecules, by increasing their retentivities, and improving peak shapes, even on different quality columns without end-capping and base-deactivating of separation matrixes.

Determination of amlodipine, indapamide and perindopril in human plasma by a novel LC-MS/MS method: Application to a bioequivalence study.

A robust and rapid UPLC-MS/MS method has been developed, optimized and validated for determination of amlodipine (AML), indapamide (IND) and perindopril (PRN) in human plasma. A positive electrospray ionization mode was used in a Xevo TQD LC-MS/MS instrument. A single sample preparation step using extraction technique was applied to extract the three analytes from plasma samples. There was no need to extract indapamide from blood samples in a further step. Extraction of the three drugs and internal standards was done using a solvent mixture composed of methyl tertiary butyl ether, dichloromethane and ethyl acetate. The prepared samples were analyzed using an Acquity UPLC HSS C18 (100 × 2.1 mm, 1.7 µm) column. Ammonium acetate and methanol, pumped at a flow rate of 0.3 ml/min, were used as a mobile phase. Method validation was done as per the US Food and Drug Administration guidelines. Linearity was achieved in the range of 0.2-15 ng/ml for AML, 0.5-50 ng/ml for IND and 0.5-120 ng/ml for PRN. Accuracy and precision were estimated and found to be within the acceptable ranges. The rapid chromatography permits analysis of many samples per batch, making the method suitable for clinical and pharmacokinetic investigations. The developed and validated method was applied to estimate AML, IND, and PRN in a fasting bioequivalence study in healthy human volunteers.

A novel, rapid and simple UPLC-MS/MS method for quantification of favipiravir in human plasma: Application to a bioequivalence study.

A novel, simple and rapid UPLC-MS/MS method was developed and validated for determination of favipiravir (FAV) in human plasma. Lamivudine was used as an internal standard (IS). The Xevo TQD LC-MS/MS was operated under the multiple-reaction monitoring mode using electrospray ionization. Precipitation with acetonitrile was used in sample preparation as it gives relatively cleaner plasma samples. The prepared samples were chromatographed using an Acquity UPLC® HSS C18 (100 × 2.1 mm, 1.8 µm) column. The mobile phase was composed of ammonium formate and methanol in a gradient mode that was pumped at a flow rate of 0.35 ml/min. The developed method was validated as per the FDA guidelines and linearity was in the range of 0.25-16 µg/ml for FAV. The intra- and inter-day precision and accuracy results were within the acceptable limits. A run time of 4.5 min and a low quantification limit of FAV allowed the application of the developed method for the determination of FAV in a bioequivalence study in healthy human volunteers.

Novel HPTLC densitometric methods for determination of tamsulosin HCl and tadalafil in their newly formulated dosage form: Comparative study and green profile assessment.

A promising combination of tamsulosin HCl and tadalafil has recently been introduced for treating two prevalent and associated urological disorders: benign prostate hyperplasia and erectile dysfunction. Novel HPTLC methods were designed and validated for assaying the cited drugs in their challenging combined formulation. Separation was achieved using HPTLC silica gel 60 F254 plates as a stationary phase with a densitometric measurement at 280 nm. The proposed methods with two different chromatographic systems were successfully applied: a conventional mixture (method I) of ethyl acetate-toluene-methanol-ammonia (5:3:2:0.5, by volume) and a greener one (method II) with ethyl acetate-ethanol-ammonia (8:2:0.1, by volume). The two methods were evaluated through a comparative study in terms of selectivity, tailing factor, developing time and concentration ranges. The greenness profile for each method was then appraised with several green guides, namely GlaxoSmithKline solvent sustainability guide, Environmental, Health and Safety (EHS) tool, National Environmental Method Index (NEMI) and Eco-scale. Moreover, method specificity and peak homogeneity were evaluated by peak purity assessment using the winCATS® software spectral correlation tool. The methods have potential for being simple, fast, economic and selective, and the greener one could be a good option for sustainable analysis of the drugs.

Quantification of amlodipine and atorvastatin in human plasma by UPLC-MS/MS method and its application to a bioequivalence study.

A robust, rapid and sensitive UPLC-MS/MS method has been developed, optimized and validated for the determination of amlodipine (AML) and atorvastatin (ATO) in human plasma using eplerenone as an internal standard (IS). Multiple-reaction monitoring in positive electrospray ionization mode was utilized in Xevo TQD LC-MS/MS. Double extraction was used in sample preparation using diethyl ether and ethyl acetate. The prepared samples were analyzed using an Acquity UPLC BEH C18 (50 × 2.1 mm, 1.7 µm) column. Ammonium formate and acetonitrile, pumped isocraticaly at a flow rate of 0.25 mL/min, were used as a mobile phase. Method validation was done as per the US Food and Drug Administration guidelines. Linearity was achieved in the range of 0.1-10 ng/mL for AML and 0.05-50 ng/mL for ATO. Intra-day and inter-day accuracy and precision were calculated and found to be within the acceptable range. A short run time, of <1.5 min, permits analysis of a large number of plasma samples per batch. The developed and validated method was applied to estimate AML and ATO in a bioequivalence study in healthy human volunteers.

Novel determination of sofosbuvir and velpatasvir in human plasma by UPLC-MS/MS method: Application to a bioequivalence study.

A novel and sensitive LC-MS/MS method was developed, optimized and validated for quantification of sofosbuvir (SOF) and velpatasvir (VEL) in human plasma using ledipasvir as an internal standard (IS). Sample preparation was done using acetonitrile for precipitation of plasma proteins. Chromatographic analysis was done on an Acquity UPLC BEH C18 column using 0.1% formic acid and acetonitrile as a mobile phase. The Xevo TQD LC-MS/MS system was run with electrospray ionization mode. The developed method was optimized and then validated according to the US Food and Drug Administration guidelines. Linearity was found to be in the range of 0.25-3500 ng/mL for SOF and 1-1000 ng/mL for VEL. A short run time of 1.5 min allows swift analysis of many plasma samples per day. The developed method was successfully utilized for estimating both SOF and VEL in the plasma of healthy human volunteers participated in a bioequivalence study.

Novel and sensitive UPLC-MS/MS method for quantification of sofosbuvir in human plasma: application to a bioequivalence study.

A novel and sensitive LC-MS/MS method was developed and validated for determination of sofosbuvir (SF) using eplerenone as an internal standard. The Xevo TQD LC-MS/MS was operated under the multiple-reaction monitoring mode using electrospray ionization. Extraction with tert-butyl methyl ether was used in sample preparation. The prepared samples were chromatographed on Acquity UPLC BEH C18 (50 × 2.1 mm, 1.7 µm) column by pumping 0.1% formic acid and acetonitrile in an isocratic mode at a flow rate of 0.35 mL/min. Method validation was performed as per the US Food and Drug Administration guidelines and the standard curves were found to be linear in the range of 0.25-3500 ng/mL for SF. The intra- and inter-day precision and accuracy results were within the acceptable limits. A very short run time of 1 min made it possible to analyze more than 500 human plasma samples per day. A very low quantification limit of SF allowed the applicability of the developed method for determination of SF in a bioequivalence study in human volunteers. Copyright © 2016 John Wiley & Sons, Ltd.

Development and Evaluation of Chemometric Models for the Estimation of Sumatriptan in the Presence of Naproxen and a Degradation Product Using UV Spectrophotometry.

BACKGROUND: Chemometrics is a discipline that allows the spectral resolution of drugs in a pharmaceutical formulation along with degradation product and it is an alternative to chromatographic methods. OBJECTIVE: Sumatriptan (SUM) is co-formulated with naproxen (NAP) and used in acute migraine attacks. SUM, which has physiological importance, has not been subjected to any stability-indicating chemometric approaches yet, so there is a need for an accurate and safe method for the assay of the cited drug in its preparations. The greenness and blueness assessment was applied using different ecological metrics, including the Green Analytical Procedure Index (GAPI), Analytical Greenness Metric (AGREE), Analytical Eco-Scale (AES) and new "blueness" evaluation using the Blue Applicability Grade Index (BAGI) tool. METHODS: SUM was determined in pharmaceutical formulation along with NAP and in presence of alkali-induced degradation product with simple and cost-effective multivariate approaches using spectrophotometric data. Three chemometric approaches were applied for the stability-indicating determination of SUM in the presence of NAP. Classical least-squares (CLS), partial least-squares regression (PLS), and principal components regression (PCR)-three multivariate calibration numerical models that were applied to the UV spectra of the mixtures-were used to achieve the best resolution. RESULTS: Sumatriptan was analyzed with mean accuracies for PLS (100.29% ± 1.318) and for PCR (100.60% ± 1.564). The presented methods were compared and validated for their quantitative analyses. Moreover, statistical comparison between the results obtained by the proposed models and the official methods showed no significant differences. CONCLUSION: The proposed multivariate calibrations were accurate and specific for quantitative analysis of the studied component. PLS is the best method that has the capacity for qualitative analysis of SUM and it is suitable for routine analysis and stability studies of SUM in QC laboratories. Various ecological assessment metrics confirmed the long-standing eco-friendliness of the suggested models. HIGHLIGHTS: Severally overlapped mixtures of SUM along with co-formulated drug NAP and an alkali-induced degradation product were analyzed by three chemometric approaches. The analytical performance of PLS and PCR was compared and validated in terms of root-mean-square error of calibration (RMSEC), SE of prediction, and recoveries. PLS gave the highest predicted concentrations with the lowest RMSEC and root-mean-square error of prediction. The standard addition was applied for accuracy assessment and the results were compared to those of official methods. Proposed models determined SUM in synthetic mixtures and pharmaceutical formulation in QC laboratories and stability studies. Ecological evaluation tools for measuring the environmental friendliness of chemicals were utilized for the first time in the analysis of SUM.

An eco-friendly smartphone based HPTLC method versus conventional densitometric one for determination of Naltrexone and Bupropion.

The rapid uprising technologies of smartphone applications and software introduced a new era for analytical detection techniques. It has transformed bench-top laboratory methods into simpler ones depending on cost-effective, portable, and widely accessible devices. In this work, two high performance thin layer chromatographic (HPTLC) methods were developed based on smartphone's camera detection and either ImageJ desktop software or Color-Picker smartphone's application as alternative techniques to conventional densitometric detection. A mixture of Naltrexone hydrochloride (NAL) and Bupropion hydrochloride (BUP) was chromatographed on HPTLC- plates using ethyl acetate, methanol, acetone, and glacial acetic acid (3:6:1:0.5, by volume) as a developing system. The developed plates were scanned at 203 nm for the densitometric analysis, then visualized by modified Dragendorff's reagent and shot by a smartphone's camera. The captured images were uploaded to either ImageJ software or Color-Picker application to detect the separated spots. The results derived from the three detection methods were compared over the concentration range of 0.4-24 & 0.6-18 µg/band for the densitometric method, 0.4-24 & 2-24 µg/band for ImageJ built method and 0.8-20 & 5-20 µg/band for Color Picker built method for NAL and BUP, respectively. The methods were found to be appropriate for assaying both active drug substances in pure forms and combined in marketed pharmaceutical formulations. The excellent sustainability of densitometric and ImageJ-based methods enabled also the assessment of their dosage form content uniformity. The greenness and sustainability of the methods were assessed by three metric tools, namely Green Analytical Procedure Index (GAPI), Analytical GREEnness Metric Approach (AGREE), and White Analytical Chemistry (WAC). The assessments results confirmed the sustainability and superiority of the proposed methods in terms of sample treatment, waste mount, energy consumption, cost, and number of analyzed samples per an hour.

Simultaneous determination of sitagliptin and metformin in their pharmaceutical formulation.

Two simple, accurate, and rapid methods were developed for simultaneous determination of sitagliptin phosphate and metformin hydrochloride in their pharmaceutical formulation. The first is a TLC method coupled with densitometry. The second is an HPLC method using a C18 column. The selectivity of the proposed methods was checked using laboratory-prepared mixtures. The proposed methods were successfully applied to the analysis of sitagliptin phosphate and metformin hydrochloride in bulk form and in their pharmaceutical formulation without interference from other additives.

Does the Ethnic Difference Affect the Pharmacokinetics of Favipiravir? A Pharmacokinetic Study in Healthy Egyptian Volunteers and Development of Level C In-vitro In-vivo Correlation.

Favipiravir is an antiviral drug used to treat influenza and is also being investigated for the treatment of SARS-CoV-2. Its pharmacokinetic profile varies depending on ethnic group. The present research examines the pharmacokinetic features of favipiravir in healthy male Egyptian volunteers. Another goal of this research is to determine the optimum dissolution testing conditions for immediate release tablets. In vitro dissolution testing was investigated for favipiravir tablets in three different pH media. The pharmacokinetic features of favipiravir were examined in 27 healthy male Egyptian volunteers. The parameter "AUC0-t" vs. percent dissolved was used to develop level C in vitro in vivo correlation (IVIVC) to set the optimum dissolution medium to achieve accurate dissolution profile for favipiravir (IR) tablets. The in vitro release results revealed significant difference among the three different dissolution media. The Pk parameters of twenty-seven human subjects showed mean value of Cpmax of 5966.45 ng/mL at median tmax of 0.75 h with AUC0-∞ equals 13325.54 ng.h/mL, showing half-life of 1.25 h. Level C IVIVC was developed successfully. It was concluded that Egyptian volunteers had comparable Pk values to American and Caucasian volunteers, however they were considerably different from Japanese subjects. AUC0-t vs. % dissolved was used to develop level C IVIVC to set the optimum dissolution medium. Phosphate buffer medium (pH 6.8) was found to be the optimum dissolution medium for in vitro dissolution testing for Favipiravir IR tablets.

A novel smartphone HPTLC assaying platform versus traditional densitometric method for simultaneous quantification of alfuzosin and solifenacin in their dosage forms as well as monitoring content uniformity and drug residues on the manufacturing equipment.

The large popularity and rapid technology of smartphones have opened new avenues for their integration into different analytical methodologies and drug quality monitoring as a portable, easily accessible, and user-friendly detector. Herein, a novel and portable smartphone-based high-performance thin layer chromatographic (HPTLC) approach is proposed for the simultaneous analysis of two urological drugs, alfuzosin and solifenacin, which treat benign prostatic hyperplasia accompanied by overactive bladder syndrome. First, chromatographic separation was accomplished using an ecofriendly mobile phase, then the developed plates were visualized using Dragendorff's reagent and photographed via a smartphone's rear-facing camera fixed on a fabricated two-illumination-source chamber. The intensities of the drug spots were quantified using open-source image analysis software ImageJ over the concentration ranges of 2.0 to 30.0 µg per band for both drugs with acceptable results in ICH validation parameters. To improve the method's accuracy and reproducibility, various construction and shooting key parameters were investigated and optimized. Moreover, the study was extended to compare the obtained results with those of a benchtop densitometric method using a Camag TLC Scanner 3 at 215.0 nm; the densitometric method provided an additional assessment tool for peak purity and was capable of assaying lower drug concentrations over a linearity range of 0.2-8.0 µg per band for alfuzosin and 0.1-6.0 µg per band for solifenacin. The fast, simple, reliable, green merits of the proposed HPTLC/smartphone method suggest that it is an excellent platform for assaying marketed combined capsules and assuring their content uniformity. Moreover, the high sensitivity of the densitometric method was used, for the first time, to determine the residual content of the cited drugs on manufacturing equipment surfaces for cleaning validation. Finally, the environmental impact of the developed methods was evaluated based on green analytical chemistry principles.

Exquisite integration of quality-by-design and green analytical approaches for simultaneous determination of xylometazoline and antazoline in eye drops and rabbit aqueous humor, application to stability study.

This work implements a stability indicating HPLC method developed to simultaneously determine xylometazoline (XYLO) and antazoline (ANT) in their binary mixture, rabbit aqueous humor and cited drug's degradates by applying analytical quality-by-design (AQbD) combined with green analytical chemistry (GAC) experiment for the first time. This integration was designed to maximize efficiency and minimize environmental impacts, as well as energy and solvent consumption. Analytical quality-by-design was applied to achieve our aim starting with evaluation of quality risk and scouting analysis, tracked via five parameters chromatographic screening using Placket-Burman design namely: pH, temperature, organic solvent percentage, flow rate, and wavelength detection. Recognizing the critical method parameters was done followed by optimization employing central composite design and Derringer's desirability toward assess optimum conditions that attained best resolution with satisfactory peak symmetry with short run time. Optimal chromatographic separation was attained by means of an XBridge® C18 (4.6 × 250 mm, 5 µm) column through isocratic elution using a mobile phase consists of phosphate buffer (pH 3.0): ethanol (60:40, by volume) at a 1.6 mL/min flow rate and 230.0 nm UV detection. Linearity acquired over a concentration range of 1.0-100.0 µg/mL and 0.5-100.0 µg/mL for XYLO and ANT, respectively. Furthermore, imperiling cited drugs' stock solutions to stress various conditions and satisfactory peaks of degradation products were obtained indicating that cited drugs are vulnerable to oxidative degradation and basic hydrolysis. Degradates' structures were elucidated using mass spectrometry. Applying various assessment tools; namely: analytical greenness (AGREE), green analytical procedure index (GAPI), analytical eco-scale, and national environmental method index (NEMI), Greenness method's evaluation was applied and proved to be green. In fact, the developed method is established to be perceptive, accurate, and selective to assess cited drugs for routine analysis.

Green TLC-Densitometric Method for Simultaneous Determination of Antazoline and Tetryzoline: Application to Pharmaceutical Formulation and Rabbit Aqueous Humor.

Ophthalmic pharmaceutical preparation containing antazoline (ANT) and tetryzoline (TET) is prescribed widely as an over the counter medication for allergic conjunctivitis treatment. Development of a selective, simple and environmentally friendly thin-layer chromatographic method established to determine both ANT and TET in their pure forms, pharmaceutical formulation and spiked aqueous humor samples. By using silica gel plates and means of a developing system consists of ethyl acetate:ethanol (5:5, by volume), the studied drugs separation was achieved, and scanning was carried out at 220.0 nm for the separated bands with a 0.2-18.0 µg/band concentration range for each of ANT and TET. Standard addition technique application was carried out to determine the proposed method validity. Statistical comparison was made between the proposed method and the official methods ANT and TET showing no significant difference concerning accuracy and precision. Furthermore, greenness profile assessment was accomplished by means of four metric tools, namely, analytical greenness, green analytical procedure index, analytical eco-scale and national environmental method index.Highlights.

LC-MS/MS-based metabolite quantitation of the antiviral prodrug baloxavir marboxil, a new therapy for acute uncomplicated influenza, in human plasma: Application to a human pharmacokinetic study.

Baloxavir marboxil (BXM) is a novel orally administrated prodrug for the treatment of acute uncomplicated influenza. In the present study, a bioanalytical LC-MS/MS method was developed and validated for the quantification of baloxavir acid (BXA), the active form of baloxavir marboxil in plasma of healthy volunteers using dolutegravir as an internal standard (IS) following plasma protein precipitation with acetonitrile. BXA and the internal standard were chromatographically separated using Waters Xterra® MS C8 column (5 µm, 4.6 × 50 mm) and a mobile phase comprised of 10.0 mM ammonium formate pH 3.5 and acetonitrile (80:20, v/v) delivered at a flow rate of 0.6 mL/min. The transitions of m/z 484.00 → 247.0 and 420.30 → 277.1 for BXA and IS, respectively in multiple reaction monitoring (MRM) mode in a positive ESI interface were used for quantitation through triple-quad mass spectrometry, API 4000. The method linearity was proven across the concentration range of 0.5-200.0 ng/mL, adjusted, and validated completely in accordance with the bioanalytical guidelines of the United States-FDA. Finally, the present method was effectively applied for the pharmacokinetic study of BXA in healthy human volunteers with accepted reproducibility and ruggedness.