Simultaneous determination of desloratadine and montelukast sodium using second-derivative synchronous fluorescence spectrometry enhanced by an organized medium with applications to tablets and human plasma

A highly sensitive first derivative synchronous spectrofluorimetric approach for the simultaneous analysis of the anti-breast cancer co-administered drugs, letrozole and tramadol in dosage forms and human plasma at nanogram levels

Letrozole is an anticancer medication prescribed for the management of estrogen receptor-positive breast cancer in postmenopausal women. Chronic pain is prevalent in patients receiving chemotherapy, leading to the use of adjuvant analgesics such as tramadol. This work introduces the first analytical approach for the concurrent quantification of letrozole and tramadol, two co-administered drugs, employing a rapid, highly sensitive, eco-friendly, and cost-effective first derivative synchronous spectrofluorimetric technique. The fluorescence of tramadol and letrozole was measured at wavelengths of 235.9 nm and 241.9 nm, respectively using a wavelength difference (Δλ) of 60.0 nm. The developed approach demonstrated exceptional linearity (r ˃ 0.999) within the specified concentration ranges for tramadol (10.0-1200.0 ng/mL) and letrozole (1.0-140.0 ng/mL). The results demonstrated that the proposed technique exhibits a high level of sensitivity, with detection limits of 0.569 and 0.143 ng/mL for tramadol and letrozole, respectively, indicating the good bioanalytical applicability. The within-run precisions, both intra-day and inter-day, for both analytes, were less than 0.71 % RSD. The developed approach was effectively applied to simultaneously estimate the mentioned drugs in their tablets and human plasma samples, achieving high percentage recoveries and low % RSD values. In order to assess the environmental sustainability of the developed approach, Analytical GREEnnessNNESS (AGREE) and the Green Analytical Procedure Index (GAPI) metric tools were employed. Both tools revealed that the developed approach is excellent green, suggesting its usage as an environmentally-friendly alternative for the routine assayof the investigated pharmaceuticals. The developed approach was validated according to the ICHQ2 (R1) requirements.

Design and synthesis of high quantum yield doped carbon nano probe derived from household sources for sensing of the anti-GERD drug pantoprazole

This contribution aims to design and validate a new green, cheap, and fast approach for determining the anti-GERD drug pantoprazole in different matrices. New S and N-doped carbon nanomaterials (S,N-CNMs) have been prepared via microwave irradiation of a mixture of widely available household sources. Remarkably, the utilization of a blend of carbamide and thiocarbamide with table sugar yields S,N-CNMs exhibiting the utmost quantum yield (54 %), hydrophilicity, as well as stable, homogeneous, and diminutive particle size distribution. Fourier transform infrared spectroscopy, transmission electron microscopy, spectrophotometry, and fluorescence spectroscopy were applied to characterize the S,N-CNMs. The S,N-CNMs have been used as a turn-off fluorescence probe to determine pantoprazole via a synergism of the inner filter effect and static quenching mechanisms. The fluorescence quenching is linearly correlated to pantoprazole concentration over the range of 1.0-25.0 µg/mL with a detection limit of 0.16 µg/mL. The developed probe exhibited good selectivity for pantoprazole in the presence of variability of substances. Therefore, it was applied for quality control of pantoprazole in pharmaceutical tablets and vials with an average recovery % of 100.10 ± 0.77 % and 100.33 ± 0.92 %, respectively. Moreover, it was successfully implemented to examine the content uniformity of pantoprazole in tablets. Furthermore, the prepared S,N-CNMs have been successfully used for the analysis of pantoprazole in human plasma after a simple protein precipitation step with a recovery % of 97.88 ± 5.72 %. The greenness and blueness of the developed method have been positively assessed by recent tools showing the eco-friendliness and applicability of the developed method.

Environmentally benign liquid chromatographic method for concurrent estimation of four antihistaminic drugs applying factorial design approach

In the last few decades, green analytical chemistry (GAC) has become a smart magical solution for the qualification and quantification of many drugs. In the current study, a direct, sensitive, and green RP-HPLC method was used to separate three anti-histaminic combinations rupatadine/montelukast, desloratadine/montelukast, fexofenadine/montelukast, and finally a mixture of rupatadine and its metabolite; desloratadine in less than 20 min. The developed method was optimized by a 23 full factorial design to improve the chromatographic responses. The proposed method was used to analyze these antihistaminic combinations at different pharmaceutical ratios. The linearity range is from 1 to 10 µg/mL for rupatadine, desloratadine, and montelukast, while for fexofenadine from 1 to 24 µg/mL drugs. The proposed method is useful in common quality control analysis of the investigated quaternary combinations because of its non-toxic and eco-friendly effects on the environment and human beings. The proposed procedure was thoroughly validated in accordance with ICH guidelines and was revealed to be accurate, reproducible, and selective. The developed methods were compared with a reported reference comparison method, where no significant difference was observed.

Facile Conversion of the Quinone-Semicarbazone Chromophore of Naftazone into a Fluorescent Quinol-Semicarbazide: Kinetic Study and Analysis of Naftazone in Pharmaceuticals and Human Serum

Naftazone is a quinone-semi carbazone drug that possesses a strong orange color, and hence it was usually analyzed colorimetrically or by HPLC-UV. However, these methods are not sensitive enough to determine naftazone in biological samples. Naftazone lacks intrinsic fluorescence and does not possess easily derivatizable functional groups. In this contribution, we introduced the first spectrofluorimetric method for naftazone assay through reduction-elicited fluorogenic derivatization through the reduction of its quinone-semicarbazone moiety to the corresponding quinol-semicarbazide derivative by potassium borohydride as a reduction probe. The solvent-dependent fluorescence of the reaction product was studied in various protic and aprotic solvents. Eventually, the fluorescence of the reduced naftazone was measured in 2-propanol at λ_emission of 350 nm after excitation at λ_ecxitation of 295 nm. The relative fluorescence intensity was linearly correlated to the drug concentration (r = 0.9995) from 10.0 to 500 ng/mL with high sensitivity, where the lower detection limit was 2.9 ng/mL. Hence, the method was effectively applied for naftazone tablets quality control with a mean %recovery of 100.3 ± 1.5, and the results agreed with those of the comparison HPLC-UV method. Furthermore, a new salting-out assisted liquid-liquid extraction (SALLE) method was established for naftazone extraction from human serum, followed by its determination using the developed reduction-based fluorogenic method. The developed SALLE method showed excellent recovery for naftazone from human serum (92.3-106.5%) with good precision (RSD ≤ 6.8%). Additionally, the reaction of naftazone with potassium borohydride was kinetically monitored, and it was found to follow pseudo-first-order kinetics with an activation energy of 43.8 kcal/mol. The developed method's greenness was approved using three green analytical chemistry metrics.

Green quantitative spectrofluorometric analysis of rupatadine and montelukast at nanogram scale using direct and synchronous techniques

Two green-sensitive spectrofluorometric methods were investigated for assay of rupatadine (RUP) [method I] and its binary mixture with montelukast (MKT) [method II]. Method I depends on measuring native fluorescence of RUP in the presence of 0.10 M H2SO4 and 0.10%w/v sodium dodecyl sulfate at 455 nm after excitation at 277 nm. The range of the first method was 0.20-2.00 µg ml-1 with detection and quantitation limits of 59.00 and 179.00 ng ml-1, respectively. Method II depends on the first derivative synchronous spectrofluorometry. The derivative intensities were measured for the two drugs in an aqueous solution containing Mcllvaine's buffer pH 2.60 at fixed Δλ of 140 nm. Each drug was estimated at zero-contribution of the other. The intensity was measured at 261 and 371 nm for RUP and MKT, respectively. The method was linear over 0.10-4.00 and 0.20-1.60 µg ml-1 with limits of detection 31.00 and 66.00 ng ml-1 and limits of quantitation 94.00 and 200.00 ng ml-1 for RUP and MKT, respectively. The method was extended to determine this mixture in laboratory-prepared mixtures and combined tablets. Method validation was performed according to ICH guidelines. Statistical interpretation of data revealed good agreement with the comparison method. Method greenness was confirmed by applying three different assessment tools.

Selective Consecutive Determination of Desloratadine and Montelukast Sodium in Their Pure and Binary Dosage Form Based on Pencil Graphite Electrochemical Sensors

In this study, we present a new, green electrochemical method for potentiometric estimation of desloratadine and montelukast sodium in their pure and binary dosage form. For that, three pencil graphite sensors were fabricated; the first one was prepared to analyse desloratadine drug (DES) by coating the graphite bar with the coating membrane, which comprises the ion pair of desloratadine and ammonium reineckate reagent (RNK), the polymer poly vinyl chloride (PVC), and the plasticizers dibutyl phthalate (DBP). The second one, which was used to analyse montelukast (MON), was constructed by using the ion pair of cadmium chloride reagent (Cd.) with montelukast and the same earlier named polymer and plasticizer. As a trial to analyse both of the drugs by the same sensor consecutively, we have constructed a combined pencil graphite electrode, which contains the two earlier suggested ion pairs, that is, we can use this electrode to selectively analyse for each drug. The proposed electrodes were effectively used for analysis of DES and MON as a single dosage form and as combined pharmaceutical preparation, without any need for prior separation that was performed depending on the difference in the efficient pH range for each sensor. The proposed sensors exhibited a Nernstian equation slopes of -30.11, 27.70, (-29.16, 29.79) mv. decade^-1 in the linearity range 5.00 × 10^-5-1.00 × 10^-2 and 1.00 × 10^-5 - 1.00 × 10^-2 M, respectively. The sensors exhibit high sensitivity according to LOD values ((0.036-0.018) - (0.025-0.026) µM), respectively, and important selectivity toward the studied drugs in presence of interfering ions and excipients. The optimum circumstances were studied, and the method was validated by application of ICH rules. Finally, the method was compared with a documented method, and the required statistical values were calculated.

Simultaneous evaluation of losartan and amlodipine besylate using second-derivative synchronous spectrofluorimetric technique and liquid chromatography with time-programmed fluorimetric detection

This study is concerned with two sensitive, fast and reproducible approaches; namely, second-derivative synchronous fluorimetry (method I) and reversed phase high-performance liquid chromatography with fluorimetric detection (method II) for synchronized evaluation of losartan (LOS) and amlodipine besylate (AML). Method I is based on measuring second-derivative synchronous fluorescence spectra of LOS and AML at Δλ = 80 nm in water. The experimental factors influencing the synchronous fluorescence of the considered compounds were sensibly adjusted. The chromatographic analysis was executed on a Nucleodur MN-C18 column of dimensions; 250 × 4.6 mm i.d. and 5 µm particle size). The fluorimetric detection was time-programmed at λem = 440 nm for AML (0.0-7.5 min) and at λem = 400 nm for LOS (7.5-10 min) after excitation at λex = 245 nm. The mobile phase is a blend of acetonitrile with 0.02 M phosphate buffer in a proportion of 45 : 55, pH 4.0, pumped using a flow rate of 1 ml min-1. The calibration plots were established to be 0.1-4.0 µg ml-1 for both drugs in method I and 0.05-4.0 µg ml-1 for both drugs in method II. The study was extended to the evaluation of the two drugs in their co-formulated tablets.

Innovative HPTLC method with fluorescence detection for assessment of febuxostat–montelukast combination and study of their protective effects against gouty arthritis

This study was designed to evaluate the potential protective effects of montelukast, febuxostat and their combination on a model of acute gouty arthritis, and to establish a HPTLC method for determination of both drugs simultaneously.