Eco-friendly, sensitive and inventive first derivative synchronous spectrofluorimetric determination of ciprofloxacin and phenylephrine in their pure form, single and combined eye drops.

A facile, sensitive, accurate and green spectrofluorimetric method was evolved for the assay of ciprofloxacin hydrochloride (CFX) and phenylephrine hydrochloride (PLN) in their co-formulated eye drops with their challengeable ratio of 30:1 for CFX and PLN, respectively. Such drops are clinically used for the treatment of eye bacterial infections. They relieve the symptoms of infection by stopping further growth of the causative microorganisms. The assay principle based on first-order synchronous spectrofluorometric scan using Δ λ = 40 nm in which PLN peak amplitudes were recorded at 283.4 nm, meanwhile CFX was measured at 326.2 nm in the same scans. The calibration curves were linear within the concentration ranges: 0.02-0.5 µg/mL and 0.5-5.0 µg/mL for PLN and CFX, respectively. The method validation was confirmed following the International Conference of Harmonization (ICH) Guidelines. This suggested method was the first one that described simultaneous analysis of PLN and CFX by a spectrofluorimetric technique. In this method, green analytical procedures were implemented to lessen occupational and environmental perils and method greenness was assessed by four assessment tools. GAPI, NEMI, AGREE and Analytical eco-scale were applied to this study and it was deduced from their results that the method had high degree of greenness as it fulfilled all requirements of GAPI, NEMI pictograms and it had high scores of analytical eco scale (97) and AGREE methods (0.82). Subsequently, it was successfully applied to assay both drugs in pure forms, pharmaceutical single and co-formulated eye drops.

Hydro-organic mobile phase and factorial design application to attain green HPLC method for simultaneous assay of paracetamol and dantrolene sodium in combined capsules.

The greenness of any analytical method has become a very important aspect of a good analytical method. However, most chromatographic methods depend on the usage of relatively large amounts of lethal and un-decaying chemicals and solvents. So, a green approach based on the full factorial design was employed to develop a simple and rapid HPLC technique for concurrent determination of paracetamol and dantrolene sodium in their combined capsules. Both drugs are highly recommended to be administered together in patients with severe musculoskeletal disorders. Avoiding the routine methodology and resorting to the modern technology represented in the usage of experimental design allows rapid determination of the studied drugs using the optimum quantity of chemicals to avoid any waste of resources. Simultaneous separation of a binary mixture of paracetamol and dantrolene sodium was accomplished using a reversed phase Hypersil C18 column using an eco-friendly isocratic eluent. The used mobile phase consisted simply of ethanol: water (40:60, v/v). Orthophosphoric acid was used to adjust the pH of the mobile phase to 4.5. Triethanolamine (0.2%) was added aiming to reduce the peak tailing. The assay was completed within less than 6 min adopting 0.8 mL/min as a flow rate. The detection was carried out using a UV-detector at 290 nm. The suggested technique shows a linear correlation over concentration ranges of 1.0-200 and 1.0-40 µg/mL for paracetamol and dantrolene sodium, respectively. The suggested technique allowed the simultaneous analysis of the two co-formulated drugs in their synthetic mixture and combined capsule. The suggested technique is considered a greener substitute for the other reported HPLC techniques through the usage of safer solvents and chemicals, along with decreasing both waste output and analysis time. The method is accurate with recoveries between 97.85 and 101.27%, precise, as %RSD for the intraday and interday precision were between 0.39 and 1.72% and very sensitive with limits of detection (LOD)'s 0.15 and 0.18 µg/ml and limits of quantification (LOQ)'s 0.48 and 0.61 µg/ml for paracetamol and dantrolene sodium, respectively. The method greenness was ensured through its assessment by four greenness metrics. It is also validated following the International Conference on Harmonization Guidelines. The recommended technique could be a good alternative to traditional methods in the routine quality control analysis of the studied drugs due to its minimum harm to the planet or human beings.

Innovative utilization of silver nanoparticles localized surface plasmon resonance for green and sensitive spectrofluorimetric analysis of sildenafil and xipamide in pure forms and pharmaceutical preparations.

A green, novel, simple and sensitive spectrofluorimetric approach was investigated and validated for the analysis of two important cardiovascular drugs namely; sildenafil citrate and xipamide using silver nanoparticles as a fluorescence probe (Ag-NPs). Silver nanoparticles were prepared through chemical reduction of silver nitrate using sodium borohydride in distilled water without using non-green organic stabilizer. These nanoparticles were stable, water soluble and had high fluorescence. After addition of the studied drugs, noticeable quenching of Ag-NPs fluorescence occurred. The intensity of Ag-NPs fluorescence was measured at 484 nm (λex 242 nm) before and after complex formation with these studied drugs. The difference between these values (ΔF) were linear with the concentrations in the following ranges (1.0-10.0 µg/mL), (0.5-5.0 µg/mL) for sildenafil and xipamide, respectively. The formed complexes did not need to be separated by solvent extraction before measurement. For proving the complex formation between the two studied drugs and silver nanoparticles, stern volmer method was applied. The suggested method was perfectly validated in compliance with the international conference on harmonization (ICH) Guidelines and the outcomes were acceptable. Furthermore, suggested technique was perfectly applied for the assay of each drug in its pharmaceutical dosage form. Eventually assessment of method greenness was performed using different tools and found that the suggested method was safe and eco-friendly.

Two green spectrofluorimetric methods for the assay of atomoxetine hydrochloride in pure form and commercial capsules with application to content uniformity testing.

Atomoxetine hydrochloride (ATX) is a potent and non-stimulant drug which was approved for the treatment of attention-deficit hyperactivity disorder. Owing to its importance, two green, simple and validated spectrofluorimetric methods were developed for its sensitive assay in pure and capsule forms. The first method (Method I) relied on measuring the enhanced fluorescence of ATX by the use of sodium dodecyl sulfate in alkaline medium at λ ex 227 nm/λ em 298 nm. The second method (Method II) involved complex formation of ATX with Erythrosine B (EB) in aqueous acidic solution resulting in quantitative quenching of the EB naive fluorescence. This complex was formed in the presence of Britton-Robinson buffer (pH 4.0). The difference in fluorescence intensity was measured at λ ex 527/λ em550 nm. The calibration curves were linear through the ranges of 0.2-2.0 µg ml-1 for Method I, 0.2-4.0 µg ml-1 for Method II with good correlation coefficient (r = 0.9998) for both methods. The suggested methods were perfectly applied for determination of ATX in its commercial capsules and content uniformity test. The greenness of the proposed methods was confirmed by three different assessment tools and it was found that both methods were green, eco-friendly and environmentally safe.

Multi-spectroscopic assay methods for concurrent determination of recent anti-gout combination, a comparative study.

Recently, Chemometric calibration methods in spectrophotometric analysis are achieving significant attention in the quality control of resolving drug mixtures and pharmaceutical formulations containing two or more drugs with overlapping spectra. The simple univariate methods have been used over the last few decades and has proven to be highly efficient and easy to apply. In this study, a comparative study was performed between some univariate and multivariate methods to determine if chemometric methods can substitute univariate methods in pharmaceutical analysis. In this study, three chemometric techniques were compared to seven univariate techniques to resolve a mixture of mefenamic acid and febuxostat in their raw materials, dosage forms and spiked human plasma. Mefenamic acid and febuxostat were used together for treatment of gout. The applied chemometric methods are partial least squares (PLS), artificial neural network (ANN) and genetic algorithm partial least squares (GA-PLS), while the used univariate methods include first derivative, second derivative, ratio spectra, derivative ratio spectra, ratio subtraction, Q-Absorbance ratio and mean centering spectrophotometric methods. The ten proposed methods were found to be green, sensitive, and rapid. They are simple and did not require any pre-separation steps. The results of both univariate and multivariate approaches were statistically compared with the reported spectrophotometric methods using student's t test and ratio variance F-test. They were also compared with each other, using one-way analysis of variance (ANOVA). These methods were assessed and validated according to ICH guidelines. The studied drugs were analyzed in their pharmaceutical dosage forms and spiked human plasma with good recoveries using the developed methods, which qualify them for routine quality control of the studied drugs.

Micellar eco-friendly HPLC method for simultaneous analysis of ternary combination of aspirin, atorvastatin and ramipril: application to content uniformity testing.

BACKGROUND: Cardiovascular disease medications such as aspirin (ASP), statins like atorvastatin (ATR), and blood pressure-lowering drugs including ACE inhibitors like ramipril (RAM) have been included in the World Health Organization (WHO) Essential Medicines List (EML) for many years. Therefore, there is a strong demand to develop a simple, rapid, and sensitive analytical method that can detect and quantitate the ternary mixture of these analytes in pharmaceutical preparations in a short run time. Lately, the analytical community focused on eliminating or reducing hazardous chemicals and solvents usage. RESULTS: A green, fast, selective, and cost-effective micellar HPLC method was established and validated for the concurrent determination of ternary combination of ASP, ATR, and RAM in the pure form and pharmaceutical preparations. Resolution of the three drugs was achieved by using a monolithic column and a micellar mobile phase consists of 0.3% triethylamine (TEA) in 90: 10 an aqueous solution of 0.12 M sodium dodecyl sulfate (SDS): n-propanol, (v/v). The pH was adjusted to 2.5 using orthophosphoric acid and a flow rate of 1.5 mL/min. was applied. To ensure method reproducibility, Valsartan (VAL) was utilized as an internal standard (IS). The UV detection of the studied drugs was performed at 210 nm. Good linearity for the three drugs was obtained over the concentration ranges of 1.0-200.0 mg/mL, 0.5-200.0 mg/mL, and 5.0-100.0 mg/mL with correlation coefficients of 0.9998,0.9999 and 0.9999 for ASP, ATR, and RAM respectively. The method sensitivity was revealed by the relatively small values of limits of detection (LOD) (0.19, 0.13 and 0.30 mg/mL) and limits of quantitation (LOQ) (0.63, 0.44 and 0.99 mg/mL) for ASP, ATR, and RAM, respectively. The retention times of ASP, ATR and RAM were 1.50, 2.3 and 4.3 min., respectively. CONCLUSIONS: The suggested technique was employed for the analysis of the three drugs in their prepared tablets maintaining the recommended pharmaceutical ratio without any interference from excipients. The method was further extended to content uniformity testing of RAM. The results were validated according to international council for harmonisation (ICH) guidelines.

Multicomponent spectrophotometric determination of a ternary mixture of widely-prescribed cardiovascular drugs by four different methods.

Four accurate, green, uncomplicated, and fast spectrophotometric procedures were established for the purpose of resolving as well as quantifying a ternary combination prescribed for cardiovascular patients, such as aspirin, atorvastatin, and ramipril. Method (A) is based on the first derivative zero-crossing spectrophotometry for the determination of aspirin and atorvastatin at 247.4 nm and 302.6 nm, respectively. Ramipril was determined using the second derivative at 211 nm. Method (B) depends on the ratio spectra first derivative (RDS) where the absorption spectrum of the ternary combination was divided by the spectrum of one of the analytes. When treated similarly, the concentrations of the other two analytes were measured using their corresponding calibration graphs. For the determination of ASP and RAM, ATR was used as a divisor with a concentration of 26 µg/mL, and the RDS values at 272.0 and 225.8 nm, respectively, were plotted against the ASP and RAM concentrations. Using 40 µg/mL ASP as a divisor, ATR was analyzed, and the RDS values at 295 nm were plotted versus the ATR concentration. Method (C) is based on the double divisor-ratio spectra derivative technique. In this technique, the derivative of the ratio spectrum is computed by dividing the absorption spectra of the studied combination by the standard spectrum of abinary combination of two of the three analytes being studied. The concentrations of the three analytes in the mixture were assayed by determining the absorbance either at the positive or the negative amplitude. For the determination of ASP, ATR, and RAM, the wavelengths used were 244, 295, and 220 nm, respectively. Method (D) was a hybrid double divisor-ratio spectra technique based on convolving the double divisor-ratio spectra with trigonometric Fourier functions. The magnitudes of the Fourier function coefficients at either maximum or minimum points were correlated to the concentration of each drug in the mixture. The specificity of the suggested methods was tested by analyzing synthetic laboratory-prepared combinations and laboratory-made tablets. Furthermore, the accuracy and precision were ensured by statistically comparing the obtained results with those obtained from comparison method using Bartlett's Test for Equality of Variances and ANOVA test.

Green Constant-wavelength Concurrent Selective Fluorescence Method for Assay of Ibuprofen and Chlorzoxazone in Presence of Chlorzoxazone Degradation Product.

Lower back pain is a universal dilemma leaving a negative effect on both health and life quality. It was found that a fixed dose combination of chlorzoxazone and ibuprofen gave a higher efficiency than analgesic alone in treatment of acute lower back pain. Based on the significant benefit of that combination, a green, sensitive, rapid, direct, and cost-effective method is created for concurrent determination of ibuprofen and chlorzoxazone in presence of 2-amino para chlorophenol (a synthetic precursor and potential impurity of chlorzoxazone) adopting the synchronous spectrofluorimetric technique. Synchronous spectrofluorimetric technique is adopted to avoid the highly overlapped native spectra of both drugs. The synchronous spectrofluorometric method was applied at Δλ = 50 nm, ibuprofen was measured at 227 nm while chlorzoxazone was measured at 282 nm with no hindering from one to another. The various experimental variables affecting the performance of the suggested technique were explored and adjusted. The suggested technique showed good linearity from 0.02 to 0.6 and 0.1 to 5.0 µg/mL for ibuprofen and chlorzoxazone, respectively. The produced detection limits were 0.27 × 10-3 and 0.03, while the quantitation limits were 0.82 × 10-3 and 0.09 µg/mL for ibuprofen and chlorzoxazone, respectively. The suggested approach was successfully applied for the analysis of the studied drugs in the synthetic mixture, different pharmaceutical preparations, and spiked human plasma. The suggested technique was validated with respect to the International Council of Harmonization (ICH) recommendations. The suggested technique was found to be simpler and greener with lower cost compared to the earlier reported methods which required complicated techniques, longer time of analysis, and less safe solvents and reagents. Green profile assessment for the developed method compared with the reported spectrofluorometric method was performed using four assessment tools. These tools confirmed that the recommended technique attained the most possible green parameters, so it could be used as a greener option in routine quality control for analyzing the two drugs in genuine form and pharmaceutical preparations.

A quality-by-design eco-friendly UV-HPLC method for the determination of four drugs used to treat symptoms of common cold and COVID-19.

An optimization approach based on full factorial design was employed for developing an HPLC-UV method for simultaneous determination of a quaternary mixture used for the treatment of symptoms related to common cold and COVID-19. The quaternary mixture is composed of paracetamol, levocetirizine dihydrochloride, phenylephrine hydrochloride and ambroxol hydrochloride. The developed technique is a green, fast and simple method that uses isocratic elution of mobile phase consisting of 20:5:75 (v/v) of ethanol: acetonitrile: 2.5 mM heptane-1-sulphonic acid sodium salt at pH 6.5 [Formula: see text] 0.02. The chromatographic separation was carried out using Hypersil BDS Cyano LC Column (250 × 4.6 mm, 5 µm) with 230 nm UV detection and 1.0 mL/min. flow rate. Avoiding the routine methodology and resorting to the modern technology-represented in the usage of experimental design-allows rapid determination of the four drugs using the optimum quantity of chemicals to avoid any waste of resources. The quaternary mixture was eluted in less than 9 min., where retention times of paracetamol, levocetirizine dihydrochloride, phenylephrine hydrochloride and ambroxol hydrochloride were found to be 2.2, 3.8, 6.6 and 8.8 min., respectively. The calibration graphs of the four drugs were linear over concentration ranges of 50.0-500.0, 0.5-20.0, 0.5-20.0 and 0.5-100.0 µg/mL for paracetamol, levocetirizine dihydrochloride, phenylephrine hydrochloride and ambroxol hydrochloride, respectively with correlation coefficients higher than 0.999. The method is accurate with mean recoveries between 99.87 and 100.04%, precise, as %RSD for the intraday and interday precision were between 0.61 and 1.64% and very sensitive with limit of detections (LOD)'s between 29 and 147 ng/mL and limit of quantification (LOQ)'s between 95 and 485 ng/mL. The proposed method was successfully applied for the analysis of the four drugs either in raw materials or in prepared tablet with the least amount of chemicals within short time. It is also validated following International Conference on Harmonization Guidelines. The proposed method was found to be green according to the most common greenness assessment tools; NEMI, GAPI, Analytical Eco-Scale and AGREE methods. The advantages of the proposed method qualify it for routine analysis of the studied drugs either in single or co-formulated dosage form in quality control labs.

Innovative localized surface plasmon resonance sensing technique for a green spectrofluorimetric assay of ketoprofen, paracetamol and chlorzoxazone in pharmaceutical preparations and biological fluids.

A green, quick and sensitive spectrofluorimetric technique was investigated and validated for the assay of three different drugs namely, ketoprofen (KPN), paracetamol (PAR), and chlorzoxazone (CLX). The method is based on fluorescence quenching of the fluorescence probe, silver nanoparticles (SNPs). The fluorescence quenching of SNPs may be attributed to the complexation between each of the studied drugs with SNPs. The fluorescence of SNPs alone or after complexation with the studied drugs were measured at 485 nm (λ ex 242 nm) without the need to extract the formed complex. Chemical reduction was employed for preparing SNPs, where silver nitrate was reduced by sodium borohydride in deionized water without adding organic stabilizer. SNPs were found soluble in water, had high stability and had a narrow emission band. The studied drugs were found to decrease the fluorescence of SNPs significantly through static quenching according to Stern-Volmer equation. Factors affecting the reaction between the drugs and NPs were carefully examined and optimized. Using the optimum conditions, the difference in the fluorescence intensity of SNPs before and after complexation with the studied drugs was in a good linear relationship with the concentration of the studied drugs, where (R 2 = 0.9998, 0.9998 and 0.9991) in the ranges of 0.5-5.0, 0.15-3.0 and 0.5-9.0 µg mL-1 for KPN, PAR and CLX, respectively. Validity of the proposed method was investigated according to ICH recommendations. The proposed technique was also employed for the analysis of each of the three drugs in commercial or laboratory prepared tablets and in spiked human plasma with very good recoveries as well as high level of accuracy and precision. This method was intended to the analysis of the proposed drugs in their single formulation and single drug administration. The suggested technique is considered an eco-friendly method, as it uses water as the safest and least expensive solvent. Moreover, the recommended technique does not involve solvent extraction of the formed complexes. Greenness assessment of the suggested procedure was accomplished by applying the four standard assessment tools. Consequently, the recommended method can be used in the routine quality control analysis of the cited drugs with minimum harmful effect on the environment as well as the individuals.

Green spectrofluorimetric assay of dantrolene sodium via reduction method: application to content uniformity testing.

Green analysis has turned out to be of a great value in all areas, including pharmaceutical analysis. Thus, it is extremely important to consider the environmental influence of each step in developing any analysis technique. The present work illustrates a validated, simple and green spectrofluorimetric method for the analysis of dantrolene sodium (DAN). The developed process is characterized by being of high sensitivity as well as being relatively inexpensive. The suggested technique based on the formation of a highly fluorescent product of DAN via its reduction by the aid of Zn/HCl system. The resulting fluorophore showed a powerful fluorescence at λ em 344 nm after excitation at λ ex 279 nm. Calibration graph revealed a great linear regression (r = 0.9998) within concentration ranging from 0.05 to 2.0 µg ml-1. The suggested method had very low detection and quantification limits of 0.010 and 0.031 µg ml-1, respectively. The applied technique was effectively used in the determination of DAN in its pharmaceutical preparations. The results were compared with those from using the official United States Pharmacopeia (USP) method and they were in a good agreement. Moreover, content uniformity testing of DAN in capsules was performed adopting the investigated technique with satisfying results. The greenness of the suggested technique was confirmed by the three standard assessment tools. Therefore, the developed technique can be used in the routine quality control analysis of DAN with minimum harmful impact on nature or individuals.

Liquid chromatographic method for the simultaneous determination of eprosartan and hydrochlorothiazide in tablets and human plasma.

A new, specific, and sensitive RP-HPLC method was developed for the simultaneous determination of eprosartan (EPR) and hydrochlorothiazide (HCT). Good chromatographic separation was achieved using a 250 x 4.6 mm id, 5 microm particle size Symmetry C18 column. The mobile phase acetonitrile-0.1 M phosphate buffer (35+65, v/v), pH 4.5, was pumped at a flow rate of 1 mL/min, with UV detection at 275 nm. The method showed good linearity in the ranges of 0.5-50 and 0.1-10 microg/mL, with LOD of 0.06 and 0.02 microg/mL and LOQ of 0.20 and 0.08 microg/mL for EPR and HCT, respectively. The proposed method was successfully applied for the analysis of the studied drugs in their synthetic mixture and co-formulated tablets. The method was further extended to the in vitro and in vivo determination of the two drugs in spiked and real human plasma. Interference likely to be encountered from the co-administered drugs was studied.

Stability-indicating polarographic determination of acyclovir through chelation with nickel(II).

A simple and sensitive, stability-indicating polarographic method was developed for the determination of acyclovir (ACV) in raw materials and dosage forms. The proposed method relies on the chelation of ACV with nickel(II) in Britton Robinson buffer (pH 5) and measuring the resulting polarographic wave either in the direct current (DCt) or differential pulse (DPP) modes. The polarographic wave has been characterized as being catalytic reduction prewave. Different experimental parameters affecting the formation of the Ni-ACV chelate and its polarographic activity were studied and optimized. The current concentration relationship was found to be linear over the range of 0.8-8 and 1-8 microg/mL, with minimum detectabilities of 0.10 and 0.19 microg/mL using DPP and DCt modes, respectively. The method was used to investigate the kinetics of the acid-induced degradation of the drug. The apparent first-order rate constants and half-life times were calculated.