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Parkinson's disease (PD) emerges as a notable health concern among the elderly population. Safinamide mesylate (SAF) is a novel and emerging add-on therapy in PD treatment. The stability of innovative drug formulations and the development of appropriate stability-indicating methods are of great importance to modern pharmaceutical analysis. The current work has established novel comprehensive stability-indicating chromatographic approaches, HPTLC coupled with densitometric quantification and HPLC–DAD, for the selective assay of SAF in pharmaceutical formulation along with its synthetic precursor impurity; 4-hydroxy benzaldehyde (4-HBD) in presence of its stress induced degradation products. The stability of SAF was investigated under different stress conditions. It was found that SAF is likely to undergo acid, base hydrolysis, and oxidative degradation. Using mass spectrometry and infrared spectroscopy, the structures of the forced degradation products were confirmed and elucidated. The dissolution behavior of Parkimedine® Tablets was also monitored in the FDA suitable medium. Multiple assessment tools were used to evaluate the environmental sustainability of the proposed methods and the reported one. The greenness tools included Complex-GAPI and AGREE metrics. In addition, the innovative concepts of "blueness" and "whiteness" evaluation were incorporated through the newly introduced BAGI and RGB12 algorithms, respectively. [ABSTRACT FROM AUTHOR]

Methyldopa, a synthesized dopamine substitute with phenolic, amine, and carboxylic groups, was used to create a selective molecular imprinted polymer (MIP) for detecting formoterol fumarate dihydrate (FFD), a long-acting beta2-agonist for asthma and COPD. The bio-inspired polymer (MD) was electro-grafted onto a pencil graphite electrode (PGE) using cyclic voltammetry in a phosphate buffer (pH 6.5). An indirect method involving a redox probe (ferrocyanide/ferricyanide) and differential pulse voltammetry measured FFD binding to the MIP's 3D cavities. The sensor showed a linear response range from 1 × 10⁻⁹ M to 2 × 10⁻¹⁰ M, with a detection limit of 1.7 × 10⁻¹¹ M. The polymethyldopa (PMD) and FFD interaction was assessed by UV spectroscopy, and the method was validated per ICH guidelines. Green analytical approaches, including RGB and GAPI, were also implemented. The goal was to use advances in molecularly imprinted polymers to develop a more precise and selective electrochemical sensor for FFD quantification. [ABSTRACT FROM AUTHOR]

Indacaterol, a β2 agonist prescribed for long-term management of patients with chronic obstructive pulmonary disease and asthma. In this study the first MISPE cartridges was developed using indacaterol as a template for its selective extraction from rat lung tissues, enabling precise pharmacokinetic evaluation at the drug's site of action. A molecular imprinting polymer was synthesized using indacaterol as a template, methacrylic acid as a functional monomer and ethylene glycol dimethacrylate as a cross-linker with a molar ratio (1: 4: 20). The polymer was characterized by a high binding capacity of 9840 ± 0.86 and high selectivity with an imprinting factor of 4.53 ± 0.12. The synthesized polymer was utilized as a sorbent in solid-phase extraction to purify and extract indacaterol from lung tissue matrix. The optimum molecularly imprinted solid-phase extraction (MISPE) conditions were 20.0 mg of molecular imprinting polymer and non-imprinting polymer, acetonitrile as the loading solvent, acetonitrile: water (20: 80; by volume) as the washing solvent, and methanol: acetic acid (90: 10; by volume) as the eluting solvent. A pharmacokinetic study was performed for indacaterol in rat lungs using the synthesized and optimized MISPE cartridge as a tool for sample purification. These parameters were determined in the lung tissues of rats emphasizing the local exposure of indacaterol to its target organ. The Cmax and Tmax were 51.020 ± 2.810 µg mL− 1 and 0.083 ± 0.001 h, respectively. The AUC 0−24 and AUC0 − inf were 175.920 ± 1.053 and 542.000 ± 5.245 µg h mL− 1, respectively. The elimination rate constant was 0.014 ± 0.00012 h− 1 and the half-life time was 48.510 ± 0.012 h. This study successfully developed and optimized MISPE cartridges using indacaterol as a template, enabling precise pharmacokinetic evaluation in rat lung tissues. The cartridges demonstrated high binding capacity and selectivity, providing crucial insights into the local exposure of indacaterol at its site of action. [ABSTRACT FROM AUTHOR]

Indacaterol, is an ultra-long-acting β2 agonist, glycopyrronium is a long-acting muscarinic-antagonist and mometasone is a synthetic corticosteroid. They were used recently in combination for the treatment of severe asthma symptoms and chronic obstructive pulmonary disease. In this work, it was the first time to develop a green and environment friendly ultra-performance liquid chromatographic method using design expert program for the analysis of the three drugs in their combined dosage form. Also, the method was bioanalytically validated for the analysis of the three drugs in spiked human plasma samples. The method was linear in range from 0.50 to 100.0 μg mL−1 for indacaterol and mometasone and from 1.0 to 150.0 μg mL−1 for glycopyrronium. It showed high accuracy where, the % recovery for indacaterol, glycopyrronium and mometasone in plasma were ranged from 94.27 to 97.86%, 96.43 to 98.75% and 96.86 to 98.43%, respectively. Also, it was precise where, the % relative standard deviation for the inter-day precision was ranged from 2.571 to 3.484%, 3.180 to 4.123% and 3.150 to 3.984% and the intra-day precision was ranged from 2.351 to 3.125%, 2.512 to 3.544% and 2.961 to 3.983% for indacaterol, glycopyrronium and mometasone, respectively. The limit of detection and the limit of quantification for indacaterol and mometasone were 0.03 and 0.10 μg mL−1 while for glycopyrronium, they were 0.16 and 0.50 μg mL−1. Highlights Analytical quality by design and green chemistry combined approach. Analytical quality by design using central composite design model for the optimization of the chromatographic conditions with the least number of runs. The first developed RP-UPLC green method for the simultaneous determination of indacterol, glycopyrronium and mometasone. The method was applied for their analysis in spiked plasma samples and combined dosage form. The method greenness was determined by analytical eco-scale. [ABSTRACT FROM AUTHOR]

A novel, highly sensitive and eco-friendly micellar-mediated spectrofluorimetric method was developed and validated for the determination of the novel antiparkinsonian drug safinamide mesylate in the presence of its related precursor impurity, 4-hydroxybenzaldehyde. The proposed approach relies on increasing the inherent fluorescence emission at 296 nm of safinamide, by forming hydrogen bonds between the mentioned drug and sodium dodecyl sulfate in the micellar system using 0.1 N HCl as a solvent, following excitation at 226 nm. A thorough investigation was conducted into the experimental factors affecting spectrofluorimetric behavior of the studied drug. A linearity plot of safinamide over the concentration range of 10.0–1000.0 ng/mL against the relative fluorescence intensities was established. The proposed method demonstrated excellent sensitivity down to the nano-gram level with detection and quantitation limits of 1.91 and 5.79 ng/mL, respectively. The studied drug was effectively determined in Parkimedine® Tablets. Furthermore, the proposed method allows for ultrasensitive quantification of safinamide in spiked human plasma, with satisfactory percentage recovery (98.97–102.28%). Additionally, the greenness assessment using the advanced green certificate classification approach, the complementary green analytical procedure index (Complex-GAPI), and the analytical GREEness metric approach (AGREE), along with the practicality check using the Blue Applicability Grade Index in addition to the all-inclusive overall whiteness evaluation using the RGB-12 model were carried out. The outcomes demonstrated the effectiveness and whiteness of the proposed technique. Clearly, the suggested approach has the advantages of being simple, requiring no pretreatment steps, and relying solely on direct measuring procedures. [ABSTRACT FROM AUTHOR]

Therapeutic drug monitoring is an important clinical testing of the drugs to monitor their concentrations in plasma in order to guarantee their optimal impact, and to avoid any side effects resulting from drug-drug interactions. A green reversed-phase high-performance liquid chromatographic method using a photodiode array detector (RP-HPLC-PDA) was developed for the simultaneous determination of three carbapenem antibiotics (Imipenem, ertapenem, and meropenem) with the co-formulated drug (cilastatin) and contraindicated drugs (probenecid and warfarin) in spiked human plasma. The separation was achieved at 25 °C using a gradient elution of a mixture of mobile phase A: methanol and mobile phase B: phosphate buffer (pH 3.0). The photodiode array detector was adjusted at 220 nm. Bioanalytical method validation was carried out as per the FDA guidelines, and the method showed good linearity ranges for the six drugs that included their Cmax levels along with low limits of quantification. Based on the results, the method was found to be accurate and precise; with high % recovery and good % RSD, respectively. The method was successfully applied to spiked human plasma, signifying a good potential to be implemented in future TDM studies of these drugs when co-administered together. [ABSTRACT FROM AUTHOR]

Two selective stability-indicating procedures were adopted for the quantification of Solifenacin succinate (SOL) along with its acid degradant, in its powder form or in pharmaceutical tablet. Under stress conditions, the acid degradation pathway of SOL was investigated, its official impurity (SOL imp-A) was obtained as the possible acid degradation product, also. A densitometric technique based on the separation of SOL from SOL imp-A employing HPTLC plates prelaminated with silica gel 60 F254 as the stationary phase and a developing solution containing methanol:chloroform:ammonia (8:1:1, v/v/v) and UV scanning of the developed bands at 220 nm. Linear regression analysis data for the calibration plot of SOL showed perfect linear relationships throughout the range of concentration 10–60 μg/band. A reversed phase C18 analytical column (4.6 × 250 mm, 5 μm) was also used to separate the mixture at a flow rate of 1 mL/min, using acetonitrile:0.05 M phosphate buffer (70:30, v/v) as the mobile phase and phosphoric acid to set pH = 3.5. Quantification was obtained at 220 nm using peak area and linear calibration curve across a concentration range of 10–70 μg/mL. The recommended procedures were applied to the existing dosage form, and they generated satisfactory results. [ABSTRACT FROM AUTHOR]

This work is concerned with exploiting the power of chemometrics in the assay and purity determination of naphazoline HCl (NZ) and pheniramine maleate (PN) in their combined eye drops. Partial least squares (PLS) and artificial neural network (ANN) were the chosen models for that purpose where three selected official impurities, namely; NZ impurity B and PN impurities A and B, were successfully determined. The quantitative determinations of studied components were assessed by percentage recoveries, standard errors of prediction as well as root mean square errors of prediction. The developed models were constructed in the ranges of 5.0–13.0 μg mL−1 for NZ, 10.0–60.0 μg mL−1 for PN, 1.0–5.0 μg mL−1 for NZ impurity B and 2.0–14.0 μg mL−1 for two PN impurities. The proposed models could determine NZ and PN with respective detection limits of 0.447 and 1.750 μg mL−1 for PLS, and 0.494 and 2.093 μg mL−1 for ANN. The two established models were compared favorably with official methods where no significant difference observed. [ABSTRACT FROM AUTHOR]

Recently, green analytical chemistry (GAC) is a key issue towards the idea of sustainability, the analytical community is focused on developing analytical methods that incorporate green chemistry principles to minimize adverse impacts on the environment and humans. Herein, we present 2 sustainable, selective, and validated chromatographic methods. Initially, lidocaine hydrochloride (LDC) and miconazole nitrate (MIC) with two preservatives; methyl paraben (MTP) and saccharin sodium (SAC) were chromatographed via TLC–densitometric method which employed ethyl acetate: methanol: formic acid (9:1:0.1, by volume) as the mobile phase with UV detection at 220.0 nm, good correlation was obtained in the range of 0.3–3.0 µg/band for MIC and LDC. Following that, RP-HPLC was successfully applied for separating quinary mixture of LDC, MIC, MTP, SAC along with LDC impurity; dimethyl aniline (DMA) using C18 column, and a gradient green mobile phase composed of methanol and phosphate buffer (pH 6.0) in different ratios with a flow rate 1.5 mL/min and UV detection at 210.0 nm, linearity ranges from 1.00 to 100.00 µg/mL for MIC, 2.00–100.00 µg/mL for LDC and 1.00–-20.00 µg/mL for MTP and DMA. No records to date regarding the determination of the two drugs, besides MTP and DMA. The proposed methods were validated according to the ICH guidelines and applied successfully to the analysis of the compounds. The methods' results were statistically compared to those obtained by applying the reported one, indicating no significant difference regarding both accuracy and precision. The methods' greenness profiles have been assessed and compared with those of the reported method using different assessment tools. [ABSTRACT FROM AUTHOR]

Reduction of environmental pollution sources is the main target of green chemistry; it is applied across the life cycle of a chemical product. Scientists try to switch to eco-friendly practices to diminish the negative impact of chemicals and solvents on the environment. Analytical chemistry is one of the main fields that mounted green chemistry approach. In this work, sensitive and selective green chromatographic methods with UV detection are described for the simultaneous determination of aspirin, rosuvastatin and clopidogrel. The first proposed method is an RP-HPLC one, which was described and successfully validated for the simultaneous separation and determination of the three components on Prontosil Hyperchom C18 (250 × 4.6 mm, 5 μm) column using an isocratic elution. The second method was a TLC spectrodensitometry in which the three components were separated, identified and quantified. The drugs were applied on silica gel plates, and developed using n-heptane: acetone: glacial acetic acid (60:40:0.4, by volume). The three drugs resolved bands were quantified by spectrodensitometric scanning at 240 nm. Both methods were validated according to ICH, statistically compared to the official methods with full greenness investigation to confirm that the proposed methods are viable alternatives for quality assessment of this combination. [ABSTRACT FROM AUTHOR]

Three novel, simple and accurate multivariate spectrophotometric assisted mathematical techniques were developed for determination of paracetamol, caffeine, drotaverine HCl and their related impurities. The used multivariate algorithms are principal component regression (PCR), partial least squares (PLS), and synergy intervals partial least squares (siPLS). Linearity of the suggested methods was found to be (1.00–14.60, 1.40–7.00, 1.40–3.80, 1.00–3.00, 1.50–3.50 and 2.50–4.50 µg/mL) for paracetamol, caffeine, drotaverine HCl, and their related impurities; p-aminophenol, theophylline and homoveratric acid, correspondingly. The presented methods were effectively implemented in the determination of the cited compounds in their laboratory prepared mixtures. Commercially available tablet preparation was also analyzed using the applied methods where no impurities were detected and without interference from tablet additives. Moreover, statistical analysis did not reveal any noticeable differences between the obtained results and those acquired from the reported method in terms of accuracy and precision. The developed multivariate algorithms were validated by means of internal and external validation sets. The obtained results showed the siPLS algorithm's superiority to PCR and PLS according to the values of correlation coefficient values (r) and the lowest root mean square error of prediction (RMSEP). The combination of four subintervals [10, 12, 14, and 17] produced the highest efficiency model. Furthermore, these methods may be an applicable substitute to HPLC ones in quality control laboratories during rush of analyses where several samples have to be analyzed in a short time. [ABSTRACT FROM AUTHOR]

Favipiravir (FAV) has been approved as an antiviral drug used in pandemic corona virus to treat covid-19. It has an amide moiety susceptible to hydrolysis and degradation in acid medium. Therefore, four simple, sensitive, and accurate stability indicating spectrophotometric methods have been developed for the determination of FAV in presence of its acid induced degradation product. The first method describes direct determination of FAV at 323 nm. Dual wavelength method was the second developed one for FAV quantitation by recording the absorbance difference at 322.7 and 270 nm. The third method involves using first derivative peak to peak amplitude at 338.0 and 308.0 nm, while difference spectrophotometry was the fourth suggested method, and it was based on recording the spectral changes at 361.3 nm as pH changes. The obtained calibration curves were linear over 4.0–22.0 µg/mL. Accuracy of the suggested procedures ranged from 99.11 to100.06, while precision results were from 0.80 to1.68. The developed methods were used to determine FAV in pure powdered form, laboratory-prepared mixtures with their degradation product, and pharmaceutical formulation without interference from its acidic degradation product.The greenness was assessed based on GAPI and ACREE metric and was found to be compatible and in reconciliation with green analytical chemistry concepts. [ABSTRACT FROM AUTHOR]

A disposable screen-printed electrode, modified by multiwalled carbon nanotubes, was created as a sensor for the measurement of vortioxetine hydrobromide as an inexpensive quick and convenient method. It was demonstrated that the multiwalled carbon nanotube screen printed electrode inside the buffer of Britton–Robinson adjusted at pH 6.0 together with anionic surface-active agent (sodium dodecyl sulfate) could significantly enhance the electrochemical oxidation of vortioxetine hydrobromide. Electrochemical response was investigated and verified on multiwalled carbon nanotube screen-printed electrode in the presence of sodium dodecyl sulfate through cyclic voltammetry and differential pulse voltammetry. Scanning electron microscopy and energy dispersive X-ray analysis were utilized to characterize the surface of multiwalled carbon nanotube screen-printed electrode. Under perfect experimental conditions, the analytical results showed direct relationship responses in the range of 6.0–60.0 ng mL−1. The limit of detection and limit of quantification were 2.0 and 6.0 ng mL−1, respectively. The results show that the recommended sensor is highly suitable, profitable, and easily applicable in quality control laboratories to achieve the fast determination for vortioxetine hydrobromide either in its pure form or in dosage form, when there is either its oxidative degradation or interfering substances. Furthermore, vortioxetine hydrobromide in spiked human serum was examined using the suggested method. Moreover, the pathway for the electrode reaction was postulated. Following that, the investigated electrochemical process was evaluated using the analytical eco-scale, which proved to be an excellent green analysis. [ABSTRACT FROM AUTHOR]

This study used an experimental design approach to optimize an HPLC method for the simultaneous determination of three pharmaceutical residues (triamcinolone, nystatin, and gramicidin) in industrial wastewater samples. The goal of using an experimental design approach was to maximize the method performance through separation enhancement and shortening the time of analysis and/or minimizing the environmental effects through the reduction in wastes and sample treatment. To achieve this goal, two steps were performed: a full factorial screening design for the three chromatographic variables, and optimization design using central composite design to select the optimum conditions that accomplished the highest resolution between adjacent peaks within a minimum run time of less than 5 min. The optimal chromatographic conditions derived from Minitab software using the desirability function were applied. Separation was carried out on a Zorbax C18 column (250 mm × 4.6, 5 μm) with gradient elution of a mobile phase composed of methanol and 0.25 M potassium dihydrogen phosphate buffer (pH 3.6) at different UV detections. For the validation of the developed HPLC method, ICH guidelines were followed, and the obtained results were found to be in compliance with the acceptance criteria. Linearity was over the concentration range of 1.00–25.00 μg/mL for triamcinilone and nystatin and 10.00–50.00 µg/mL for gramicidin. The proposed method was successfully applied to quantify the three studied pharmaceutical compounds in rinsing wastewater samples. [ABSTRACT FROM AUTHOR]

A sensitive, specific and eco‐friendly reversed‐phase‐HPLC method was developed and validated for the determination of paracetamol, caffeine and drotaverine HCl along with their related impurities. The separation was accomplished using an X‐bridge C18 column (5 μm; 250 mm × 4.6 mm inner diameter) and a green mobile phase consisting of methanol and 0.02 M phosphate buffer at pH 5.0 in the gradient elution mode. The detector used was a diode array detector. The proposed method was validated in accordance with the International Conference on Harmonisation guidelines. Linear regressions were found in the range of 1–100, 1–100, 2–60, 1–20, 0.50–30 and 1–15 μg/mL for paracetamol, caffeine, drotaverine HCl, p‐aminophenol, theophylline and 3,4‐dimethoxyphenylacetic acid, respectively. The suggested method was successfully applied for the determination of the studied drugs in their tablet dosage form without interference from any excipients. No discernible difference was found between the obtained results and official or reported methods, statistically, in terms of both accuracy and precision. Dissolution profiling of the studied tablet was also performed using the suggested procedure. Moreover, the greenness profile was assessed using three different tools, namely, the National Environmental Methods Index, the Analytical Eco‐Scale and the Analytical GREEnness Metric Approach. The acquired results assert the agreement of the assay with green chemistry principles. [ABSTRACT FROM AUTHOR]

Formoterol fumarate dihydrate (FFD) is a long-acting β2 agonist, while Fluticasone propionate (FP) is a synthetic glucocorticoid receptor agonist. Both are used to manage chronic asthma and chronic obstructive pulmonary disease. The objective of this work is the quantitative analysis of the two drugs concurrently in their pure raw powder and medication dosage form, synthetic laboratory mixtures by three simple, precise, sensitive, and accurate spectrophotometric techniques operating on ratio spectra with the advantages of low-cost, high sensitivity, and no previous separation. Method (I) is based on the ratio subtraction method, which allows FP to be determined without the interference of FFD at its λmax of 236 nm. Method (II) is the first derivative of the ratio spectra, which enabled the measurement of peak amplitude of D1 spectra at 233.2 nm for FP and 301.0 nm for FFD. Method (III) is the ratio difference spectrophotometry, where the difference in values between (214.4 and 236.0 nm) was calculated for the determination of FP; and the difference of peak amplitudes at 270.0 and 290.0 nm for the estimation of FFD. The linearity of the calibration curve considered the range of concentrations of 2.0–12.0 and 2.5–25.0 µg/mL for FFD and FP, respectively. The accuracy and precision of the three achieved methods have been assayed to verify their validation according to ICH guidelines. They were 100.1 ± 1.3, 101.5 ± 0.5, and 101.2 ± 1.2 for FP, and 99.2 ± 1.6 and 100 ± 2 related to FFD. Regarding precision, the relative standard deviation was not more than 1.5%. The specificity of the three methods was estimated through their determination in various synthetic laboratory mixes. Additionally, the obtained results by the suggested procedures are compared statistically to those obtained by the reported HPLC technique. Another statistical comparison was done using a one-way ANOVA test; all of them showed no discernible differences. The three methods are specific, simple, and do not require sophisticated instruments. They can be employed in quality control laboratories for routine assays of two drugs in pure raw powder, synthetic laboratory-prepared mixes, and medication dosage forms quantitatively, and have been successfully utilized and validated. [ABSTRACT FROM AUTHOR]

This work represents first attempt for potentiometric determination of the most recent antidiabetic; omarigliptin. Three sensors, employing potassium tetrakis (p‐chlorophenyl) borate as a lipophilic cation exchanger, were developed and compared. One liquid contact ion‐selective electrode and two carbon paste‐based solid contact ones, plain one and another one modified with polyaniline nanoparticles, were employed. Performances of fabricated sensors were assessed as per IUPAC recommendations. Incorporation of hydrophobic polyaniline nanoparticles as ion‐to‐electron transducer layer at solid contact/ion‐sensitive membrane interface enhanced sensitivity and stability of the third sensor showing LOD of 2.5×10−7 mol L−1 and slope of 58.57 mV decade−1. The three sensors were applied for omarigliptin determination in presence of its degradation products, in dosage form and spiked human plasma. [ABSTRACT FROM AUTHOR]

Sulfacetamide sodium is a widely prescribed sulfonamide drug due to its topical antibacterial action on eye and skin. Four impurities are stated in the British Pharmacopoeia among which are sulfanilamide and dapsone. This work presents two specific, accurate and precise chromatographic methods for the simultaneous determination of a mixture of sulfacetamide sodium, sulfanilamide and dapsone. The first method is an isocratic RP-HPLC where the separation of components was achieved on C18 column. A green mobile phase was used consisting of methanol:water (60:40, v/v). The flow rate was 1.0 mL/min and effluent was monitored at 273 nm. The second method is a TLC-spectrodensitometric one where good separation was achieved by using silica plates and a mobile phase consisting of chloroform:dichloromethane:acetic acid (6:2.5:1.5, by volume). Determination was done by densitometry in the absorbance mode at 273 nm. Both methods were validated in compliance with ICH guidelines. They were also successfully applied for the determination of sulfacetamide sodium and its impurities in Ocusol® ophthalmic solutions. The obtained results were statistically compared to the results obtained by applying the official methods of analysis of each component where no significant difference was found with respect to accuracy and precision. [ABSTRACT FROM AUTHOR]

Currently, all researchers are concentrating their efforts on countering the COVID-19 pandemic. The majority of patients are managed at home, according to recent statistics. An OTC triple action combination comprising paracetamol (PAR), aspirin (ASP), and diphenhydramine (DIPH) is commonly given for pain relief, fever control, and as a night-time sleep aid. This combination is currently recommended for COVID-19 patients as part of symptomatic treatment and management. In this work, three smart, simple, accurate, eco-friendly, and cost-effective spectrophotometric methods are developed for simultaneous determination of PAR, ASP, and DIPH in their combined over-the-counter caplet dosage form without any prior separation steps. The first method is the first derivative spectrophotometry (D1) which determined PAR at 259.7 nm. The second one is the dual-wavelength in ratio spectra (DWRS) for determination of ASP at 214.1 and 220.1 nm after using 10.0 μg/mL of PAR as a divisor, where PAR was a constant, and the wavelengths difference equal to zero for DIPH. The third method is the double divisor-ratio difference spectrophotometric one (DD-RD) which was based on using the sum of 15.0 µg/mL of each of PAR and ASP as a double divisor, and the difference in amplitudes was measured at two wavelengths ∆P(214.5–226.0) for determination of DIPH. The developed methods have been validated as per ICH guidelines. Furthermore, the three suggested methods were employed successfully to assay marketed pharmaceutical formulation and to investigate the content uniformity of the dosage units in accordance with the United States Pharmacopeia's guidelines. Finally, the greenness profile of the proposed methods was assessed and compared with the reported method using the analytical eco-scale system, national environmental method index (NEMI), green analytical procedure index (GAPI), and analytical greenness (AGREE) metric. The results from the proposed methods statistically agreed with those obtained by the reported one, with no significant differences in accuracy and precision. [ABSTRACT FROM AUTHOR]

This work aimed to enhance the purposing profile of Etodolac (ETD) in Human Hepatocellular Carcinoma (HCC) HepG2 cells using sodium deoxycholate stabilized zein nanospheres (ETD-SDZN NSs). ETD-SDZN NSs were formulated using the nan-precipitation method and were characterized, in particular, in terms of mean particle size, zeta potential, encapsulation efficiency, colloidal stability and bioaccessibility. Estimations of cytotoxicity, cellular uptake, cell cycle progression, Annexin-V staining, mRNA expression of apoptotic genes and oxidative stress evaluations were conducted. The ETD-SDZN NSs selected formula obtained an average particle size of 113.6 ± 7.4 nm, a zeta potential value of 32.7 ± 2.3 mV, an encapsulation efficiency of 93.3 ± 5.2%, enhanced bioaccessibility and significantly reduced IC50 against HepG2 cells, by approximately 13 times. There was also enhanced cellular uptake, accumulation in G2-M phase and elevated percentage cells in pre-G1 phase, significant elevated mRNA expression of P53, significant reduced expression of Cyclin-dependent kinase 1 (CDK1) and Cyclooxygenase-2 (COX-2) with enhanced oxidative stress by reducing glutathione reductase (GR) level, ameliorated reactive oxygen species (ROS) generation and lipid peroxidation outputs. ETD-SDZN NSs obtained a supreme cell death-inducing profile toward HepG2 cells compared to free ETD. The method of formulation was successful in acquiring the promising profile of ETD in HCC as a therapeutic molecule due to ameliorated cellular uptake, proapoptotic and oxidant potentials. [ABSTRACT FROM AUTHOR]

Sofosbuvir and daclatasvir are co-formulated as directly acting antiviral agents used for treatment of hepatitis C virus. Two chromatographic methods were developed for their determination; the first one is an Reversed phase-high performance liquid chromatography (RP-HPLC) method, in which the separation was performed on C8 Zorbax® SB column (4.6 × 250 mm, 5 μm) using acetonitrile:water:0.05 M phosphate buffer, pH = 8 (50:45:5, v/v/v) as a mobile phase, and ultraviolet detection was performed at 280 nm. Good resolution was obtained, and linearity was confirmed in the range of 10–100 μg/mL for both drugs. The second method is Thin layer chromatography (TLC)-densitometric one, in which sofosbuvir and daclatasvir were separated on silica gel plates using ethyl acetate:hexane:methanol (9:0.5:0.5, v/v/v) as a developing system and the scanning wavelength was 280 nm. Linearity was confirmed over a concentration range of 0.4–25.4 μg/band for sofosbuvir, whereas for daclatasvir linearity scanning was in the range of 0.4–12.8 μg/band. Both antiviral agents can be quantified simultaneously in one analytical run, which is a great time- and cost-saving valor of the developed methods. This valor is even more important in the case of the combined dosage form (Darvoni® tablets) to the pharmaceutical market. [ABSTRACT FROM AUTHOR]

Tolperisone and etodolac were proven to have synergistic effect for patients of acute low back pain associated with musculoskeletal spasm. In this work, a specific, highly sensitive and reproducible analytical method was developed and validated for the simultaneous determination of tolperisone and etodolac in human plasma using liquid chromatography‐tandem mass spectrometric technique. Liquid–liquid extraction was optimized for sample preparation. Zorbax C8 column (3.5 μm, 50 × 4.6 mm) was used, carrying a mobile phase mixture of 10.0 mM ammonium formate:acetonitrile (40:60, v/v) pH 3.8, running in an isocratic mode. Chlorzoxazone acted as an internal standard. Sample volume of injection was 5.0 μL, and analysis was achieved within 2.5 min. Detection and quantitation were performed by electrospray ionization mass spectrometry using the multiple‐reaction monitoring mode. The proposed method could determine the analytes in the range of concentration 0.5–200.0 ng mL−1 for tolperisone and 0.05–20.0 μg mL−1 for etodolac. Findings of inter‐ and intraday precisions were ≤12.3% with accuracy of ±5.0%. Pharmacokinetics study for the two drugs after oral administration of healthy human volunteers was achieved with the aid of application of the developed study. [ABSTRACT FROM AUTHOR]

Cyclizine (CYZ); an antiemetic compound; is widely misused for its euphoric or hallucinatory effects, either by oral or intravenous routes. The concomitant abuse of CYZ among addicted adolescents contributes to neuromuscular disorders that are life-threatening. Consequently, with the company of 1-Methylpiperazine (MPZ) and diphenylmethanol (DPM, Benzhydrol) as pharmacopoeia-reported CYZ impurities, a novel spectrofluorimetric assay for the detection of CYZ, has been established either in human plasma samples or in its parenteral formulation. The native fluorescence of CYZ has been investigated under various conditions. Different parameters affecting relative fluorescence intensity of CYZ including diluting solvent, surfactant, plasma protein solvent, and pH were studied and optimized. The linearity obtained between the fluorescence intensity at emission wavelength 350 nm after excitation at 244 nm and the corresponding CYZ concentrations was in the range 10–1000 ng/mL for measurement of CYZ either in pure form or in human plasma samples, with a appropriate correlation coefficient (r = 0.9999) and 3.10 ng/mL as the limit of detection and 9.41 ng/mL as the limit of quantitation. The suggested procedure was created and validated in accordance with ICH guidelines for quantification of CYZ either in its pure form or its dosage form, and FDA guidelines for the assay of CYZ in human plasma. Finally, in silico study and ADMET predictions were conducted for the studied drug impurities to estimate their pharmacokinetic behaviors. The results showed that both CYZ impurities have higher cellular permeability and maximum tolerated doses, DPM has higher BBB and CNS permeability than MPZ, while MPZ exceeds DPM in total clearance and volume of distribution. [ABSTRACT FROM AUTHOR]

Impurity profiling of a pharmaceutical compound is now taking great attention during quality assessment of pharmaceuticals, as presence of small amount of impurities may affect safety and efficacy. In this work, a novel TLC chromatographic method coupled with densitometric detection was established for the simultaneous quantification of naphazoline HCl, pheniramine maleate and three of their official impurities, namely; naphazoline impurity B, pheniramine impurities; A & B. Chromatographic separation was carried out on TLC aluminum silica plates F254, as a stationary phase, using methanol: ethyl acetate: 33.0% ammonia (2.0: 8.0: 1.0, by volume), as a mobile phase. Plates were examined at 260.0 nm and International Council for Harmonisation (ICH) guidelines were followed for method's validation. Important factors, such as; composition of mobile phase and detection wavelengths were optimized. Linearity was achieved over the ranges of 2.0–50.0 µg band−1 for naphazoline, 10.0–110.0 µg band−1 for pheniramine, 0.1–10.0 µg band−1 for naphazoline impurity B and 2.0–50.0 µg band−1 for both pheniramine impurities. The proposed method was assessed in terms of accuracy, precision and robustness where satisfactory results (recovery % ≈ 100% and RSD < 2) were obtained. The method was also applied for the simultaneous determination of naphazoline HCl and pheniramine maleate, in Naphcon-A® eye drops, with respective recoveries of 101.36% and 100.94%. Method greenness was evaluated and compared to the reported HPLC one via environmental, health and safety tool. The developed method has much potential over the reported one of being simple, selective, economic and time saving for the analysis of the five cited compounds. [ABSTRACT FROM AUTHOR]

Ipragliflozin degradation behavior was studied under different conditions: acidic, basic, photolytic, oxidative and thermal degradation conditions. This forced degradation study showed the extensive degradation of Ipragliflozin under acidic, basic and oxidative conditions while showed high stability under thermal and photo-degradation conditions. The separation of Ipragliflozin and its degradation products was done using Hypersil Gold® UPLC C18 column with 1.9 μm particle size (3 × 50 mm) as stationary phase and a mobile phase composed of acetonitrile: potassium monobasic phosphate buffer pH 3 (50:50; v/v) delivered at flow rate of 0.6 mL min−1. Validation of the proposed method was carried out in accordance to the International Council for Harmonisation's guidelines. The method was found to be linear within the concentration range 5.0–50.0 µg mL−1 with a limit of detection of 1.48 µg mL−1. Accuracy was proven as the percentage recovery was 98.57 ± 0.40 and the percentage relative standard deviation was 0.82 which ascertained the precision. After chromatographic separation, mass characterization was used to structurally elucidate the degradation products and to propose the degradation pathway. Kinetics parameters of oxidative, acidic and basic degradation processes were determined and it was demonstrated that the degradation appears to follow a pseudo-first-order reaction. The simplicity and sensitivity of the proposed method promote its regular use in quality control laboratories. [ABSTRACT FROM AUTHOR]

Diphenhydramine (DIPH) has become one of the world's most widely abused over‐the‐counter medications. In addition to relieving allergy symptoms, it is also recognized for causing elevated energy and mild euphoric effects. The U.S. Food and Drug Administration (FDA) has recently warned about serious problems at high doses including heart problems, seizures, coma or even death among addicted teenagers. Herein, a simple, cost‐effective, and reliable nanocomposite based electrochemical sensor was designed for DIPH quantification in biological fluids. Introducing the functionalized Fe3O4 nanoparticles (NPs) into the inner‐filling solution and the PVC‐based ion sensing membrane has been employed and compared to the classical potentiometric approach. The nanoparticles were incorporated to endorse in situ cooperative ion‐pairing interaction between the ionophore and DIPH, and to improve the selectivity and detection limit (9.5×10−8 M). Nernstian potentiometric response was achieved for DIPH over the concentration range of 1.0×10−7 to 1.0×10−2 M with a slope of 59.0±0.2 mV/decade. Inherent merits of the proposed sensor include fast response time (6 s), superior stability (60 days) with higher sensitivity and selectivity towards DIPH without interference from co‐formulated drugs and several ions commonly found in biological matrices. The proposed sensor was successfully applied to the potentiometric determination of DIPH in different biological fluids (plasma and human milk) with an average recovery of 99.06±1.95 % and 100.34±1.92 %, respectively. As a consequence, the developed ISE might be the ideal choice for in‐line DIPH measurements in plasma samples to identify overdose ingestion and its related symptoms, as well as for quality‐control laboratories without prior treatments. [ABSTRACT FROM AUTHOR]

Novel screen‐printed electrodes (SPEs) were constructed for the quantitation of nicorandil (NIC) in its pharmaceutical formulations. Different ion‐exchangers and plasticizers were investigated, but the optimal potentiometric response was obtained using nicorandil‐phosphotungstate (NIC‐PTA) ion associate and tricresyl phosphate as a plasticizer. A Nernstian response of 58.80±1 mV/decade was obtained over a concentration range of (1×10−6–1×10−2) M with 1×10−5 M as a detection limit. Sensor morphology was characterized using scanning electron microscopy (SEM). The method was validated for the assay of NIC with high selectivity, accuracy (average recovery=100.54 %), and precision (%RSD≤2). [ABSTRACT FROM AUTHOR]

Recent studies have suggested that irisin may act as a potential neurokine. Exercise and L-carnosine supplementation showed neuroprotective effects in Alzheimer's disease (AD)–like conditions. However, the regulation of irisin in the hippocampus of streptozotocin (STZ)–induced memory impairment and its relation to insulin signalling remain to be investigated. This study was designed to compare the effect of swimming exercise and L-carnosine intake on serum, CSF and hippocampal irisin in rats received intracerebroventricular (ICV) injection of STZ. Rats were recruited in swimming paradigm, received oral carnosine (100 mg/kg/day) or vehicle treated. After 5 weeks, rats were sacrificed after neurobehavioural testing. CSF and serum irisin were determined. Hippocampal tissues were used to assess expression of FNDC5/irisin, BDNF and proteins related to insulin signalling, in addition to β-amyloid peptide and phosphorylated tau protein levels. We observed decreased hippocampal, but not CSF or serum, irisin in ICV-STZ-injected rats. Exercise and carnosine intake almost normalized hippocampal FNDC5/irisin expression which was associated with reduced soluble β-amyloid peptide and phosphorylated tau protein, improved BDNF and insulin signalling proteins, with corresponding mitigated cognitive impairments. However, hippocampal FNDC5/irisin was not correlated with serum or CSF irisin levels. Histologically, both interventions ameliorated the hippocampal damage in STZ-injected rats. The current study reveals that carnosine is equivalent to exercise in reversing cognitive decline and Alzheimer's biomarkers. In both interventions, enhancement of hippocampal FNDC5/irisin and insulin signalling may be involved in mediating these neuroprotective effects. [ABSTRACT FROM AUTHOR]

Ramucirumab (RAMU) is a recently US Food and Drug Administration‐approved monoclonal antibody that is included in various anticancer protocols. It has a structural complexity and high degradation risk that have a significant effect on its safety and effectiveness. The major aim of this work was to assess the degradation pattern of RAMU based on physicochemical characterization. Mechanical agitation, repeated freeze–thaw cycles, pH and temperature were the selected stress conditions to which RAMU samples were subjected. The SE‐HPLC method was applied and validated to monitor the RAMU monomer along with its aggregates and/or fragments. The purity of the separated peaks together with system suitability parameters were determined through the calculation of percentage purity and percentage drop in RAMU concentration. The results were interpreted by correlating them with those of dynamic light scattering and reducing and non‐reducing sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Samples incubated at pH 2.0–10.0 and 37°C for up to 4 weeks were analysed, recording detection of reversed phase (RP) aggregates and low molecular weight peptide fragments. Similarly, samples under short‐term storage conditions of 4 weeks at different temperatures (−20, 2–8, 25, 37 and 50°C) showed low molecular weight peptide fragments but to a lesser extent. These results highlight the alarming effect on RAMU multidose vial efficacy and safety. [ABSTRACT FROM AUTHOR]

Fungal infections of the paranasal cavity are among the most widely spread illnesses nowadays. The aim of the current study was to estimate the effectiveness of an in situ gel loaded with voriconazole--clove oil nano-transferosomes (VRC-CO-NT) in enhancing the activity of voriconazole against Aspergillus flavus, which causes rhinosinusitis. The nephrotoxic side effects of voriconazole may be reduced through the incorporation of the clove oil, which has antioxidant activity that protects tissue. The Box-Behnken design was applied to formulate the VRC-CO-NT. The particle size, entrapment efficiency, antifungal inhibition zone, and serum creatinine concentration were considered dependent variables, and the soybean lecithin, VRC, and CO concentrations were considered independent ones. The final optimized formulation was loaded into a deacetylated gellan gum base and evaluated for its gelation, rheological properties, drug release profile, permeation capabilities, and in vivo nephrotoxicity. The optimum formulation was determined to be composed of 50mg/mL lecithin, 18mg/mL VRC, and 75mg/mL CO, with a minimum particle size of 102.96 nm, an entrapment efficiency of 71.70%, an inhibition zone of 21.76 mm, and a serum creatinine level of 0.119mmol/L. The optimized loaded in situ gel released 82.5% VRC after 12 hours and resulted in a 5.4-fold increase in drug permeation. The in vivo results obtained using rabbits resulted in a nonsignificant differentiation among the renal function parameters compared with the negative control group. In conclusion, nasal in situ gel loaded with VRC-CO-NT is considered an efficient novel carrier with enhanced antifungal properties with no signs of nephrotoxicity. [ABSTRACT FROM AUTHOR]

Two accurate and sensitive chromatographic methods have been introduced and validated for the simultaneous determination of thioctic acid, benfotiamine and cyanocobalamin in bulk powders and in their pharmaceutical formulation. Method A is reversed-phase ultra performance liquid chromatographic method with an isocratic elution, where a rapid separation was accomplished on a Zorbax C8 column using a mobile phase of acetonitrile:0.05 M phosphate buffer (pH 6 adjusted by o-phosphoric acid) (23:77, v/v). The retention times (t R) were 0.578, 0.852 and 1.376 for cyanocobalamin, benfotiamine and thioctic acid, respectively. The separated peaks were revealed at 210.0 nm. Method B is a thin-layer densitometric method where the separation of the studied drugs was carried out on silica gel plates using methanol–chloroform–heptane-1-sulphonic acid sodium salt (0.4%) (7:3:0.1, by volume) as a mobile phase, and scanning of the separated bands was done at 240.0 nm. The retardation factor (R f) values were 0.17, 0.48 and 0.75 for cyanocobalamin, benfotiamine and thioctic acid, respectively. Validation of the methods was achieved following ICH guidelines and the applied methods succeeded to determine the cited drugs in their pure forms and capsules. Results were statistically compared to the manufacturer's method where no significant difference was observed. [ABSTRACT FROM AUTHOR]

Two selective, sensitive and environmentally safe LC methods were developed and validated for determination of paracetamol, caffeine, ergotamine tartrate and metoclopramide in coformulated antimigraine tablets along with p‐aminophenol, p‐nitrophenol and theophylline as officially specified impurities. The first is based on high‐performance thin‐layer chromatography (HPTLC) coupled with densitometric quantitation. Separation was achieved on HPTLC silica gel 60 F254 plates as stationary phase using ethyl acetate:aqueous ammonium hydroxide solution:glacial acetic acid (10.0:0.4:0.1, by volume) as a developing system followed by scanning of the separated bands at 210.0 nm. The subsequent method depends on HPLC with diode array detection. The LC separation was accomplished on a Scharlau C18 (250 × 4.6 mm, 5 μm) column using a mixture of 20.0 mm sodium dihydrogen phosphate, pH 3.0, adjusted with o‐phosphoric acid and methanol, at a flow rate of 1.3 mL/min in a gradient elution program. The separated peaks were detected at 210.0 nm. The proposed methods have been validated and proven to meet the requirements outlined in the International Council for Harmonisation (ICH) guidelines. The greenness profile evaluation was carried out using three tools, namely, the National Environmental Method Index, the Analytical EcoScale and the Green Analytical Procedure Index tool, and a comparative study was then conducted. Successful application of the developed methods for determination of the cited quaternary mixture in Metograine tablets confirms their suitability regarding the analytical performance and ecological impact in quality control assay and impurity profiling purposes. [ABSTRACT FROM AUTHOR]

In a contribution to stability profiling of the recent antidiabetic drug, omarigliptin (OMR), two stability-indicating chromatographic methods were developed and validated. Stability profiling was performed for OMR under different stress conditions as acidic, alkaline, oxidative, photolytic and thermal degradations. Structures elucidation to all formed degradation products were identified using IR and mass spectrometry. Thin Layer Chromatography (TLC) and High-Performance Liquid Chromatography (HPLC) were used. In TLC-densitometric method, aluminum TLC plates precoated with silica gel G.F254 were used as stationary phase along with methanol: ethyl acetate: 33% ammonia (2:8:1, v/v/v) as mobile phase. The obtained chromatograms were scanned at 254 nm over concertation range of 5–70 μg band−1 for OMR. The second chromatographic method was an HPLC one with diode array detection and RP-C18 column with isocratic elution. Mobile phase used was composed of phosphate buffer pH 3.5: acetonitrile (80, 20, v/v), delivered at flow rate of 1.0 mL min−1. Diode array detector was adjusted at 230 nm with linearity range of 15–180 μg mL−1 for OMR. Several factors affecting TLC and HPLC efficiency have been carefully studied. The developed methods were validated according to International Conference on Harmonization guidelines and successfully applied for assessment of OMR in bulk powder and tablets. [ABSTRACT FROM AUTHOR]

Sitagliptin, an oral antidiabetic drug, is an effective medication for lowering blood glucose level either as monotherapy or in combination with other antidiabetic drugs. This work aims for the fabrication of a potentiometric sensor for sitagliptin detection. The sensor was designed by doping the polyvinyl chloride polymeric ion-selective membrane with calix[4]arene as an ionophore which highly improved the linearity range (1 × 10−6—1 × 10−2 M), sensitivity, selectivity and limit of detection (6.3 × 10−7 M) compared to ionophore-free membrane. The method was then validated according to the International Council for Harmonization (ICH) guidelines. The sensor was successfully employed to determine sitagliptin in bulk and pharmaceutical dosage form without any pre-treatment steps. Moreover, to demonstrate the deployability of the proposed sensor; it has been applied for the dissolution testing of sitagliptin by in-line continuous monitoring of sitagliptin release as a function of time from the pharmaceutical dosage form into the dissolution medium. This in-line dissolution monitoring has many advantages such as there is no need for the frequent sampling followed by the complicated procedures of samples treatment. Finally, the proposed potentiometric method was evaluated using the analytical eco-scale and has proved to be excellent green analysis in which solvent consumption and pre-treatment of samples were not necessary for its application. [ABSTRACT FROM AUTHOR]

Prednisolone acetate (PNO) and fluorometholone (FRT) are corticosteroids, co-formulated with moxifloxacin HCl (MFX) and cromolyn sodium (CML), respectively. PNO has a negligible quantum yield and its hydrolytic degradation products have enhanced fluorescence, which is 250-fold greater. FRT is a nonfluorescent drug, but its hydrolytic degradation products show reasonable fluorescence; MFX and CML have native fluorescence. Two methods were proposed based on the determination of PNO and FRT via their hydrolytic degradation products in the presence of other degradation products. Method (A) was developed for simultaneous determination of PNO and MFX in the presence of PNO degradation products by measuring peak amplitudes of the first derivative (1D) of its enhanced fluorescence; PNO and MFX were measured at 345 and 473 nm, respectively. Method (B) is a synchronous fluorescence spectroscopic method for simultaneous determination of FRT and its co-formulated drug CML in the presence of its degradation products. Fluorescence intensities were measured at Àem 283 and 347 nm for FRT and CML, respectively, using AÀ = 99.20 nm. Validation of the proposed methods was conducted as per International Council for Harmonisation (ICH) guidelines. The proposed methods were successfully applied for the determination of the proposed drugs in bulk powder, ophthalmic solution, and rabbit's aqueous humour. [ABSTRACT FROM AUTHOR]

Cyclizine (CYZ) abuse is commonly reported, either through oral or intravenous routes, for its euphoric or hallucinatory effects. The concomitant misuse of CYZ among addicted teenagers leads to life-threatening neuromuscular disorders. Consequently, two green and validated chromatographic methods were developed for the determination of CYZ, an antiemetic drug, in its parenteral formulation in the presence of 1-methyl piperazine and diphenylmethanol (benzhydrol) as the pharmacopeial stated impurities of CYZ. The first method was TLC-densitometry that relied on using a mixture consisting of ethyl acetate:isopropanol:ammonia (9.5:1:0.5, by volume) as a developing system, TLC 60 F254 silica gel plates as a stationary phase and detection of the scanned bands was performed at 210.0 nm. On the other hand, the second method was UPLC which based on the separation of CYZ and its impurities using a mobile phase consisting of ethanol and acidic water at pH 5 adjusted by phosphoric acid in the ratio of (60:40, %v/v) at flow rate 0.2 mL min−1 and UV detection were carried out at 210.0 nm. The greenness profile of the established methods was evaluated and calculated for the first time for CYZ and its toxic impurities through different assessment tools like analytical eco-scale, analytical method volume intensity and greenness profile methods. Validation of the developed methods was carried out in accordance with the guidelines of the International Conference on Harmonization. The suggested methods were accurate, reliable, time and cost-saving. Therefore, they could be used in quantification of CYZ abuse and its toxic impurities in parenteral formulation for routine quality control. The results achieved by applying the suggested methods were statistically analyzed and compared with those given by reported one and no significant differences were obtained regarding both precision and accuracy. [ABSTRACT FROM AUTHOR]

Prednisolone acetate (PDN) is a corticosteroid anti-inflammatory liable to degradation under different conditions and used with antibiotics in eye drops. Two selective stability-indicating separation techniques were developed for simultaneous determination of PDN and moxifloxacin HCl (MXF) binary mixture in pure forms, ophthalmic formulation, in the presence of PDN impurities and in the presence of their degradation products. The first method was based on HPTLC separation using silica gel 60 F254 HPTLC plates, and a developing system of toluene: ethyl acetate: methanol: ammonia (5.0: 6: 2.0: 0.05, v/v/v/v) is used with detection at 254 nm. The second method was HPLC using a mobile phase of acetonitrile: methanol: deionized water, pH 2.8 (25.0: 35.0: 40.0, v/v/v), at 254 nm. A kinetic study utilizing the developed HPLC method for PDN degradation under different stress conditions was performed. Furthermore, the method was applied for determination in rabbit aqueous humor. Validation was conducted as per ICH guidelines, and system suitability was ascertained. The calibration curves were constructed in the range 0.10–25.00 and 0.20–50.00 μg band−1, for PDN and MXF by HPTLC, while for HPLC, it was 0.02–50.00 and 0.10–50.00 μg mL−1 for both drugs, in order. [ABSTRACT FROM AUTHOR]

Nanosized adsorbents when used in potentiometric methods of analysis usually show better performance rather than the traditional potentiometric approach; this is attributed to the high specific surface area of the nanomaterial used in addition to the lack of internal diffusion resistance, thus improving their adsorption capacity. In the presented work, a rapid and sensitive potentiometric determination of chlorpheniramine maleate (CPM) and pseudoephedrine hydrochloride (PSE) in pure form, in pharmaceutical preparation, and in biological fluid was developed based on functionalized magnetic nanoparticles (Fe3O4). This strategy was compared with the classical potentiometric strategy. Three types of sensors were constructed using phosphotungstic acid (PTA), β-cyclodextrin (β-CD), and β-cyclodextrin-conjugated Fe3O4 magnetic nanoparticles for the potentiometric determination of each of CPM and PSE. The prepared sensors were characterized in regards to their composition, life duration, working pH range, and response time. The sensors have demonstrated promising selectivity to CPM and PSE in the presence of pharmaceutical formulation excipients, plasma matrix, and a diversity of both organic and inorganic interfering materials. The developed sensors have displayed good responses. Statistical comparison of the achieved results with a reported method has revealed no significant difference regarding both accuracy and precision. [ABSTRACT FROM AUTHOR]

Simple, accurate, precise, sensitive, and validated high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC)--densitometric methods were developed for the simultaneous determination of chlorpheniramine maleate (CPM), pseudoephedrine HCl (PSE), and ibuprofen (IBF) in tablet dosage form. In method A, reversed-phase (RP)-HPLC analysis was performed on Zorbax C8 column (150 mm x 4.6 mm, 5 μm particle size i.d.), using a mobile phase consisting of methanol--acetonitrile--distilled water (pH 4) using orthophosphoric acid in the ratio (80:10:10, v/v) and fl ow rate of 0.7 mL min-1. Quantifi cation was achieved with ultraviolet (UV) detection at 220 nm. In method B, TLC analysis was carried out on an aluminum-backed sheet of silica gel 60 F254 layer using ethyl acetate--methanol--ammonia (8:2:0.8, v/v) as the mobile phase. Quantifi cation was carried out with UV detection at 262 nm. The validation of the proposed methods was applied according to the International Conference on Harmonization (ICH) guidelines. The suggested methods were successfully applied for the determination of the cited drugs in bulk powder and commercial dosage form. [ABSTRACT FROM AUTHOR]

Abstract: A facile, fast and specific method based on liquid chromatography–tandem mass spectrometry (LC–MS/MS) for the simultaneous quantitation of paracetamol, chlorzoxazone and aceclofenac in human plasma was developed and validated. Sample preparation was achieved by liquid–liquid extraction. The analysis was performed on a reversed‐phase C18 HPLC column (5 μm, 4.6 × 50 mm) using acetonitrile–10 mM ammonium formate pH 3.0 (65:35, v/v) as the mobile phase where atrovastatin was used as an internal standard. A very small injection volume (3 μL) was applied and the run time was 2.0 min. The detection was carried out by electrospray positive and negative ionization mass spectrometry in the multiple‐reaction monitoring mode. The developed method was capable of determining the analytes over the concentration ranges of 0.03–30.0, 0.015–15.00 and 0.15–15.00 μg/mL for paracetamol, chlorzoxazone and aceclofenac, respectively. Intraday and interday precisions (as coefficient of variation) were found to be ≤12.3% with an accuracy (as relative error) of ±5.0%. The method was successfully applied to a pharmacokinetic study of the three analytes after being orally administered to six healthy volunteers. [ABSTRACT FROM AUTHOR]

Fluorometholone (FLM) and Sodium Cromoglycate (CMG) are co-formulated in ophthalmic preparation and showed marked instability under different conditions. Two specific, sensitive and precise stability-indicating chromatographic methods have been developed and validated for their determination in the presence of their degradation products and FLM impurity. Ten components were efficiently separated by them. The first method was HPTLC-spectrodensitometry, where the separation was achieved using silica gel 60 F254 HPTLC plates and developing system of ethyl acetate: methanol (9:1, v/v). The second method was a reversed phase HPLC associated with kinetic study of the degradation process and was successfully applied for determination of the studied compounds in spiked rabbit aqueous humor. The mobile phase was acetonitrile: methanol: 0.05 M potassium dihydrogenphosphate (0.1% trimethylamine); pH 2.5, adjusted with orthophosphoric acid (20: 30: 50, by volume). In both methods, the separated components were detected at 240 nm and system suitability was checked. Good correlation was obtained in the range of 0.10-24.00 and 0.20-48.00 µg band−1, for FLM and CMG by HPTLC. While for HPLC, the linearity ranges from 0.01-50.00 and 0.05-50.00 µg mL−1 for both drugs. The methods were applied in pharmaceutical formulation, where they were compared to the reported method with no significant difference. [ABSTRACT FROM AUTHOR]

Gliquidone (GQ) is an oral hypoglycemic agent, belonging to second-generation sulfonylurea derivatives. New high-performance thin-layer chromatography (HPTLC) and ultra-performance liquid chromatography (UPLC) methods have been developed and validated and used for complete stability study of GQ following International Conference on Harmonization guidelines. GQ was subjected to stress and forced degradation under hydrolytic, oxidative and photolytic conditions. The drug was found to be unstable under acidic, alkaline and oxidative conditions with the formation of gliquidone sulfonamide (GQS), while a marked stability was confirmed under thermal and photolytic stress conditions. GQS is the British pharmacopeial impurity A of GQ and also considered as its synthesis intermediate. The developed chromatographic methods have been utilized for anticipating the degradation behavior of GQ under the studied conditions and then used for quantitation of GQ and GQS either in their pure forms or in laboratory prepared mixtures. The methods were successfully applied to GQ in pharmaceutical formulation. The methods have the advantages of being sensitive and less time consuming compared with the reported methods. The obtained results were statistically compared with a reported HPLC method showing no significant difference regarding both accuracy and precision. [ABSTRACT FROM AUTHOR]

Two specific, sensitive, rapid and accurate chromatographic methods have been developed, optimized and validated for the simultaneous determination of sulfacetamide sodium and prednisolone acetate in pure forms and in their binary mixture. The first method is an isocratic Reversed phase-high performance liquid chromatography method where a rapid separation was achieved on a Zorbax ODS column using a green mobile phase of methanol: water (80:20, v/v) and pH adjusted to 5.0 ± 0.2 with orthophosphoric acid. The retention times (tR) were 2.21 and 3.64 min for sulfacetamide sodium and prednisolone acetate, respectively. The separated peaks were detected at 254 nm. The second method is a thin layer chromatography-densitometric method where the two drugs were separated on silica gel plates using a simple mobile phase of chloroform: methanol (90:10, v/v) and scanning of the separated bands was at 254 nm. The retardation factors (Rf) values were 0.37 and 0.64 for sulfacetamide sodium and prednisolone acetate, respectively. The suggested methods were validated in compliance with the ICH guidelines and were successfully applied to determine both drugs in their pure forms, laboratory prepared mixtures and dosage form. The obtained results were statistically compared to the official method where no significant difference was obtained with respect to both accuracy and precision. [ABSTRACT FROM AUTHOR]

Degradation of active ingredients is common during the production, transportation, and storage of the pharmaceutical preparations. The resulted degradation products can affect the pharmaceuticals’ therapeutic effect. Also, they may have some toxic properties that make them have deleterious effects on patients. Nifuroxazide, antitumor, antimetastasis, and antidiarrheal agent, has been detected in pharmaceutical formulation by two sensitive, selective, and cheap methods. The first method was densitometric thin-layer chromatography technique. The compound was detected in the presence of its degradation products without any interference. Limits of quantification and detection values were 200 and 94.3 ng/band, respectively. The method was linear in the range 0.2–12 µg/band with mean recovery% ±relative standard deviation (RSD)% = 99.97% ± 1.414. The second method was developed using simple high-performance liquid chromatography technique. The method was successfully able to separate the proposed compound from its degradation forms in the presence of pentoxiftylline as an internal standard without any interference in less than 5 min. The method also detected nifuroxazide degradation products down to 500 ng/mL. Both methods were statistically compared to a reported method with no significant difference in performance. [ABSTRACT FROM PUBLISHER]

Background: Analysis of complex mixture containing three or more components represented a challenge for analysts. New smart spectrophotometric methods have been recently evolved with no limitation. A study of different novel and smart spectrophotometric techniques for resolution of severely overlapping spectra were presented in this work utilizing isosbestic points present in different absorption spectra, normalized spectra as a divisor and dual wavelengths. A quaternary mixture of drotaverine (DRO), caffeine (CAF), paracetamol (PCT) and para-aminophenol (PAP) was taken as an example for application of the proposed techniques without any separation steps. The adopted techniques adopted of successive and progressive steps manipulating zero /or ratio /or derivative spectra. The proposed techniques includes eight novel and simple methods namely direct spectrophotometry after applying derivative transformation (DT) via multiplying by a decoding spectrum, spectrum subtraction (SS), advanced absorbance subtraction (AAS), advanced amplitude modulation (AAM), simultaneous derivative ratio ( S1DD), advanced ratio difference (ARD), induced ratio difference (IRD) and finally double divisor-ratio difference-dual wavelength (DD-RDDW) methods. Results: The proposed methods were assessed by analyzing synthetic mixtures of the studied drugs. They were also successfully applied to commercial pharmaceutical formulations without interference from other dosage form additives. The methods were validated according to the ICH guidelines, accuracy, precision, repeatability, were found to be within the acceptable limits. Conclusion: The proposed procedures are accurate, simple and reproducible and yet economic. They are also sensitive and selective and could be used for routine analysis of complex most of the binary, ternary and quaternary mixtures and even more complex mixtures. [ABSTRACT FROM AUTHOR]