Insights of different analytical approaches for estimation of budesonide as COVID-19 replication inhibitor in its novel combinations: green assessment with AGREE and GAPI approaches.

Simple, direct, rapid, and sensitive HPLC and spectrophotometric methods were established for simultaneous estimation of a novel combination of budesonide and azelastine (BUD/AZL) in their laboratory-prepared mixture and dosage form according to the medicinally recommended ratio 1:4.28. Budesonide is an important inhalation corticosteroid that plays a vital role in the inhibition of COVID-19 replication and cytokine production. The first chromatographic method was created for the simultaneous estimation of BUD epimers in the presence of AZL with excellent efficiency in a relatively short chromatographic run (< 9 min). The separation of BUD epimers with AZL was carried out on a C18 column using acetonitrile: phosphate buffer of pH 3.5 adjusted by 0.2 M orthophosphoric acid (40:60, v/v) as a mobile phase, UV detection at 230 nm and a flow rate of regulated at 2 mL/min. Besides, three spectrophotometric methods were applied for the simultaneous determination of the provided mixture adopting zero order, first order derivative, and ratio first derivative approaches. The Zero-order spectrophotometry was used for the determination of AZL in presence of BUD, where BUD shows no absorbance at 290 nm. The first derivative amplitude at 265 nm (1D265) (zero-crossing of AZL) and the ratio of first derivative amplitudes at 270 nm (1DD270) using 10.0 µg mL-1 AZL as divisor was chosen for the simultaneous determination of BUD in the presence of AZL in the binary mixture. The proposed methods were found to be rectilinear in the concentration range of (0.4-40.0 µg mL-1) and (0.05-40.0 µg mL-1) for BUD and AZL, respectively in the HPLC method. Whereas the concentration range for AZL in the zero-order method was (1.0-35.0 µg mL-1) and for BUD in the first derivative and ratio derivative method was (6.0-20.0 µg mL-1). Validation of the suggested approaches according to the ICH criteria was performed. Furthermore, to ensure the proposed approaches' greenness, The AGREE and GAPI metrics were utilized, and the afforded results revealed an excellent greenness of the proposed approaches.

Development of three ecological spectroscopic methods for analysis of betrixaban either alone or in mixture with lercanidipine: greenness assessment.

Three eco-friendly spectrophotometric methods were developed for determination of the novel anticoagulant drug, betrixaban (BTX). The first method (method A) was based on direct analysis of BTX at 229.4 nm on the zero-order spectrum using methanol as the optimum solvent. While the second method (method B) was based on measuring difference absorption value (ΔA) of BTX at 335 nm, which was obtained from pH-induced spectral difference (difference spectra of BTX in 0.1 M NaOH versus 0.1 M HCl). The third method (method C) was based on measurement of the first-derivative amplitudes of BTX and its co-administered Ca channel blocker lercanidipine (LER) at 304 and 229 nm for simultaneous assay of BTX and LER, respectively. All methods were linear over concentration ranges of 1.0-20.0 and 8.0-80.0 µg ml-1 for BTX in methods A and B, respectively, and of 1.0-20.0 and 1.0-25.0 µg ml-1 for BTX and LER, respectively, in method C. The three methods were fully validated and assessed for greenness by three metrics: analytical eco-scale, green analytical procedure index and Analytical GREEnness metrics. The results indicated the validity and greenness of the proposed methods. Moreover, the methods were applied to assay the studied analytes in their dosage forms with high percentage of recovery and low percentage of relative s.d. values.

Quantitative proton nuclear magnetic resonance method for simultaneous analysis of fluticasone propionate and azelastine hydrochloride in nasal spray formulation.

A facile, rapid, accurate and selective quantitative proton nuclear magnetic resonance (1H-qNMR) method was developed for the simultaneous determination of fluticasone propionate (FLP) and azelastine hydrochloride (AZH) in pharmaceutical nasal spray for the first time. The 1H-qNMR analysis of the studied analytes was performed using inositol as the internal standard and dimethyl sulfoxide-d6 (DMSO-d6) as the solvent. The quantitative selective proton signal of FLP was doublet of doublet at 6.290, 6.294, 6.316 and 6.319 ppm, while that of AZH was doublet at 8.292 and 8.310 ppm. The internal standard (inositol) produced a doublet signal at 3.70 and 3.71 ppm. The method was rectilinear over the concentration ranges of 0.25-20.0 and 0.2-15.0 mg ml-1 for FLP and AZH, respectively. No labelling or pretreatment steps were required for NMR analysis of the studied analytes. The proposed 1H-qNMR method was validated efficiently according to the International Council on Harmonisation guidelines in terms of linearity, limit of detection, limit of quantification, accuracy, precision, specificity and stability. Moreover, the method was applied to assay the analytes in their combined nasal spray formulation. The results ensured the linearity (r 2 > 0.999), precision (% RSD < 1.5), stability, specificity and selectivity of the developed method.

Optimization and Validation of a Facile RP-HPLC Method for Determination of Betrixaban and Lercanidipine in Pharmaceutical and Biological Matrices.

A simple, accurate, rapid and sensitive reversed-phase high-performance liquid chromatography (RP-HPLC) method was established for determination of a novel non-vitamin K antagonist oral anticoagulant drug, betrixaban, and its co-administered calcium-channel blocker drug, lercanidipine, in pharmaceutical formulations and biological fluids. The proposed HPLC method was the first chromatographic method applied to estimate this mixture in a short chromatographic run (<6 min), high resolution between betrixaban/lercanidipine (Rs = 7.12) and acceptable values of limit of detection (LOD), limit of quantification (LOQ) and percentage of relative standard deviation (%RSD). The chromatographic separation was performed on a cyano column using a mobile phase composed of acetonitrile:methanol:water (35:35:30, v/v/v) containing 0.2% orthophosphoric acid adjusted to pH 3.2 by triethylamine, programmed with a flow rate of 1 mL/min with UV detection at 240 nm. The proposed method showed linearity over the concentration ranges of (0.20-20.0 µg/mL) and (0.25-25.0 µg/mL) for betrixaban and lercanidipine, respectively. All validation parameters met the acceptance criteria according to ICH guidelines in terms of linearity, LOD, LOQ, accuracy, precision, robustness, specificity and system suitability. The method was applied to assay the studied analytes in their pharmaceutical formulations with high % recovery (98-102%) and low %RSD (<1.5). Furthermore, the proposed method was successfully applied for the determination of betrixaban in spiked human plasma.

Eco-Friendly Green Liquid Chromatographic Determination of Azelastine in the Presence of its Degradation Products: Applications to Degradation Kinetics.

Background: Green solvents such as microemulsion were used in the proposed method because they play a vital role in the analytical method's influence on the environment. Objective: A highly sensitive, specific, and validated stability-indicating eco-friendly green microemulsion liquid chromatography (MELC) method was developed for separation of the antihistaminic drug Azelastine HCl (AZL) from its degradation products with application to degradation kinetics. Methods: Chromatographic separation was operated on a C18 column with a microemulsion mobile phase, which consists of 0.1 M sodium dodecyl sulphate, 10% n-propanol, 1% n-octanol, and 0.3% triethylamine, by using 0.02 M phosphoric acid at pH 3.5 and irbesartan as internal standard. The eluted compounds were monitored at 210 nm with flow rate 1 mL/min at ambient temperature. Results: A linear dependence of the peak area on drug concentration over the concentration range of 0.1 to 25 µg/mL was achieved with an LOD of 0.04 µg/mL and an LOQ of 0.10 µg/mL. Moreover, the proposed method was successfully applied for determination of AZL in eye drops and metered dose nasal inhaler as well as to study the kinetics of alkaline, acidic, neutral, oxidative, and photolytic degradation processes of AZL according to the International Council for Harmonization guidelines. Conclusions: The proposed method could be used as a harmless alternative for quality control analysis of the mentioned drug, without interference from dosage form additives or decomposition products. Highlights: A highly sensitive stability-indicating eco-friendly green MELC method was developed for the separation of the antihistaminic drug AZL from its degradation products.

Simultaneous Determination of Gatifloxacin and Prednisolone in their Bulk Powder, Synthetic Mixture and Their Combined Ophthalmic Preparation Using Micellar Liquid Chromatography.

A simple rapid and accurate micellar high performance liquid chromatographic method was improved and validated for the analysis of mixture containing gatifloxacin sesquihydrate (GTF) and prednisolone acetate (PRED) in their synthetic mixture and their combined preparation. The separation was achieved using a C18 column, micellar mobile phase consisted of 0.2 M sodium dodecyl sulfate, 12.5% n-propanol and 0.3% triethylamine in 0.02 M orthophosphoric acid at pH 7.0 at a flow rate of 1 ml/min with UV detection at 270 nm. The proposed method was found to be rectilinear over the concentration ranges of 5.0-45 µg ml-1 and 10-50 µg ml-1 with recovery percentage of 99.95 ± 0.82 and 100.07 ± 0.84 for GTF and PRED, respectively. The separation of both drugs was accomplished in a very short chromatographic run (<5 min), the method is reproducible (R.S.D. < 1.0%) and show satisfactory resolution between GTF and PRED (Rs) = 1.67. The developed method was validated according to International Conference on Harmonization (ICH) guidelines. The limit of detection of the proposed method was 0.33 and 0.21 µg ml-1, and the limit of quantitation was 0.99 and 0.64 µg ml-1 for GTF and PRED, respectively.

Validated spectroscopic methods for determination of anti-histaminic drug azelastine in pure form: Analytical application for quality control of its pharmaceutical preparations.

Two simple, sensitive, rapid, validated and cost effective spectroscopic methods were established for quantification of antihistaminic drug azelastine (AZL) in bulk powder as well as in pharmaceutical dosage forms. In the first method (A) the absorbance difference between acidic and basic solutions was measured at 228nm, whereas in the second investigated method (B) the binary complex formed between AZL and Eosin Y in acetate buffer solution (pH3) was measured at 550nm. Different criteria that have critical influence on the intensity of absorption were deeply studied and optimized so as to achieve the highest absorption. The proposed methods obeyed Beer's low in the concentration range of (2.0-20.0µg·mL-1) and (0.5-15.0µg·mL-1) with % recovery±S.D. of (99.84±0.87), (100.02±0.78) for methods (A) and (B), respectively. Furthermore, the proposed methods were easily applied for quality control of pharmaceutical preparations without any conflict with its co-formulated additives, and the analytical results were compatible with those obtained by the comparison one with no significant difference as insured by student's t-test and the variance ratio F-test. Validation of the proposed methods was performed according the ICH guidelines in terms of linearity, limit of quantification, limit of detection, accuracy, precision and specificity, where the analytical results were persuasive.

Validated sensitive spectrofluorimetric method for determination of antihistaminic drug azelastine HCl in pure form and in pharmaceutical dosage forms: application to stability study.

A highly sensitive, simple and rapid spectrofluorimetric method was developed for the determination of azelastine HCl (AZL) in either its pure state or pharmaceutical dosage form. The proposed method was based on measuring the native fluorescence of the studied drug in 0.2 M H2 SO4 at λem  = 364 nm after excitation at λex  = 275 nm. Different experimental parameters were studied and optimized carefully to obtain the highest fluorescence intensity. The proposed method showed a linear dependence of the fluorescence intensity on drug concentration over a concentration range of 10-250 ng/mL, with a limit of detection of 1.52 ng/mL and limit of quantitation of 4.61 ng/mL. Moreover, the method was successfully applied to pharmaceutical preparations, with percent recovery values (± SD) of 99.96 (± 0.4) and 100.1 (± 0.52) for nasal spray and eye drops, respectively. The results were in good agreement with those obtained by the comparison method, as revealed by Student's t-test and the variance ratio F-test. The method was extended to study the stability of AZL under stress conditions, where the drug was exposed to neutral, acidic, alkaline, oxidative and photolytic degradation according to International Conference on Harmonization (ICH) guidelines. Copyright © 2016 John Wiley & Sons, Ltd.

Simultaneous determination of enalapril and hydrochlorothiazide in pharmaceutical preparations using microemulsion liquid chromatography.

A rapid high-performance liquid chromatography procedure for analytical quality control of mixture containing enalapril maleate (ENM) and hydrochlorothiazide (HCT) in their pharmaceutical preparations was developed using a microemulsion as an eluent. The separation was performed on a column packed with cyano-bonded stationary phase adopting UV detection at 210 nm using a flow rate of 1 mL/min. The optimized microemulsion mobile phase consisted of 0.2 M sodium dodecyl sulfate, 1% octanol, 10% n-propanol and 0.3% triethylamine in 0.02 M phosphoric acid, and pH was adjusted at 3.5. The proposed method was found to be linear over the concentration ranges 1-100 and 0.05-5 µg/mL for ENM and HCT, respectively with a correlation coefficient of 0.9999 for both drugs. The developed method was validated in terms of specificity, linearity, lower limit of quantification, lower limit of detection, precision and accuracy. The proposed method is rapid (5 min), reproducible (relative standard deviation <2.0%) and achieves a satisfactory resolution between ENM and HCT (resolution factor = 3.62). The mean recoveries of the analytes in tablets were in agreement with those obtained from a comparison method, as revealed by statistical analysis of the obtained results using Student's t-test and the variance ratio F-test.

Microemulsion liquid chromatographic method for simultaneous determination of simvastatin and ezetimibe in their combined dosage forms.

A rapid HPLC procedure using a microemulsion as an eluent was developed and validated for analytical quality control of antihyperlipidemic mixture containing simvastatin (SIM) and ezetimibe (EZT) in their pharmaceutical preparations. The separation was performed on a column packed with cyano bonded stationary phase adopting UV detection at 238 nm using a flow rate of 1 mL/min. The optimized microemulsion mobile phase consisted of 0.2 M sodium dodecyl sulphate, 1% octanol, 10% n-propanol, and 0.3% triethylamine in 0.02 M phosphoric acid at pH 5.0. The developed method was validated in terms of specificity, linearity, lower limit of quantification (LOQ), lower limit of detection (LOD), precision, and accuracy. The proposed method is rapid (8.5 min), reproducible (RSD < 2.0%) and achieves satisfactory resolution between SIM and EZT (resolution factor = 2.57). The mean recoveries of the analytes in pharmaceutical preparations were in agreement with those obtained from a reference method, as revealed by statistical analysis of the obtained results using Student's t-test and the variance ratio F-test.

Simultaneous determination of norfloxacin and tinidazole binary mixture by difference spectroscopy.

A simple and rapid difference spectroscopic method was developed for the simultaneous determination of binary mixture of norfloxacin (NF) and tinidazole (TZ) without prior separation. The proposed method depends upon measuring the absorbance of NF at 291.6 nm which is the zero crossing point on the difference spectra of TZ in 0.1 N NaOH vs. 0.1 N HCl. Similarly, the absorbance of TZ was measured at 344.4 nm which is the zero crossing point on the difference spectra of NF. Beer's law was obeyed in the concentration range of 2-20 and 5-50 µg/mL for NF and TZ, respectively. The lower limits of detection (LOD) of NF and TZ are 0.23 and 0.36 µg/mL, respectively, while the lower limits of quantification (LOQ) of NF and TZ were 0.70 and 1.08 µg/mL, respectively. The precision of the method was satisfactory; the maximum value of relative standard deviations did not exceed 1.5% (n=10). The accuracy, expressed as recovery is between 98.25 and 101.8% with relative error of 0.29 and 0.23 for NF and TZ, respectively. The proposed method was successfully applied for the determination of both drugs in bulk powder, laboratory prepared mixture and commercial dosage forms such as tablets without interference from the commonly encountered excipients and additives. The results obtained are in good agreement with those obtained by the reference methods.

Synthesis and pharmacological evaluation of novel fused thiophene derivatives as 5-HT2A receptor antagonists: molecular modeling study.

Novel derivatives of cyclopentathienopyrimidinediones 6, pyridothienopyrimidinediones 7, ethyl cycloheptathiophene-3-carboxylates 10, ethyl tetrahydrothienopyridine-3-carboxylates 11, tetrahydrocycloheptathienopyrimidin-4(3H)-ones 12, tetrahydrotriazolobenzothienopyrimidin-5(4H)-ones 17 and tetrahydro-5H-cycloheptathienopyrimidin-4(3H)-ones 21 have been synthesized and tested for their 5-HT2A antagonist activity. Preliminary pharmacological studies showed that compounds 3-[2-[4-phenylpiperazin-1-yl]ethyl]-6,7-dihydro-5H-cyclopenta[b]thieno[2,3-d]pyrimidine-2,4(1H,3H)-dione 6a and ethyl 2-[[4-(2-methoxyphenyl)piperazin-1-yl]acetylamino]-4,5,6,7-tetrahydro-6-methylthieno[2,3-c]pyridine-3-carboxylate 11d were found to be the most active molecules as 5-HT2A antagonists. Molecular modeling and pharmacophore prediction methodology are used to study the structural features required for 5-HT2A antagonist properties of the active compounds compared with nonactive species by means of the molecular mechanic method. The 2-methoxy substituent in the structure of 11d seems to be necessary for its full antagonistic properties. Optimal placement of basic nitrogen relative to the plane of thiophene core was found to have a profound effect on affinity and biological activity.

Simultaneous determination of ritodrine and isoxsuprine using coupling technique of synchronous fluorimetry and H-point standard addition method.

Simultaneous determination of two structurally related ss(2) adrenergic receptor agonists namely, Ritodrine HCl (RTH) and Isoxsuprine HCl (ISP) was performed using coupling technique of synchronous fluorimetry and H-point standard addition method. Under optimum conditions, linear determination ranges were 1.48 - 14.80 x 10(-6) mol L(-1) and 1.54 - 15.44 x 10(-6) mol L(-1) for ISP and RTH respectively. RTH and ISP could be determined simultaneously without interference from each other when their concentration ratio varies from 5:1 to 1:5 in the mixed sample. The proposed method was applied to the determination of RTH and ISP in synthetic mixture of pharmaceutical samples, the accuracy and precision of the results were satisfactory.

Analysis of flunarizine in the presence of some of its degradation products using micellar liquid chromatography (MLC) or microemulsion liquid chromatography (MELC)--application to dosage forms.

The separation of flunarizine hydrochloride (FLZ) and five of its degradation products--1-[bis(4-fluorophenyl)methyl]-4-(3-phenyl-2-propenyl)piperazine, 4-oxide (A), bis(4-fluorophenyl)methanone (B), bis(4-fluorophenyl)methanol (C), 1-(3-phenyl-2-propenyl)piperazine(D), and 1-[bis-4-fluorophenyl) methyl] piperazine (E)--could be accomplished by reversed phase liquid chromatography using either micellar or microemulsion mobile phases. Cyanopropyl-bonded stationary phase has been used with UV detection at 254 nm. Microemulsion mobile phase consisting of 0.15 M SDS, 10% n-propanol, 1% n-octanol, and 0.3% triethylamine in 0.02 M phosphoric acid of pH 7.0, has been used for the separation of FLZ and its degradation products (B, C, D, and E). Micellar mobile phases consisting of 0.15 M sodium dodecyl sulphate (SDS), 10% n-propanol, 0.3% triethylamine (TEA) in 0.02 M phosphoric acid of pH values either 4.0 or 6.8 have been used for the separation of FLZ from its degradation products, i.e. either from (B, C, D, and E) or from (A, B, C, and D), respectively. Micellar liquid chromatography (MLC) was applied to the determination of FLZ in pure form as well as in dosage forms; the calibration graph was linear over the concentration range of 0.15-50 microg/mL with detection limit of 0.02 microg/mL (4.19 x 10(-8)M).