Comparative HPTLC study for simultaneous determination of ivabradine and metoprolol using UV and fluorescence detectors.

New, simple, accurate, sensitive and validated high performance thin layer chromatographic (HPTLC) method coupled with UV absorbance mode and fluorescence (FL) detectors which were used for simultaneous determination of ivabradine (IVA) and metoprolol (MET) in their bulk and pharmaceutical dosage form using TLC silica 60 F254 plates and non-fluorescent TLC silica gel 60 plates. The developing system was chloroform: methanol: formic acid: ammonia (8.5:1.5:0.2:0.1, v/v). Desnitometric analysis in UV absorbance mode was set at λ = 275 nm. While, fluorescence mode was performed with excitation at 260 nm for quantitative simultaneous determination of IVA and MET using optical filter K320. The retention factors values were 0.45 ± 0.05 and 0.89 ± 0.01 of IVA and MET, respectively. UV absorbance mode, linearity was 50.0-600.0 ng/band for IVA and 50.0-900.0 ng/band for MET. For fluorescence mode, the linearity ranges were 18.0-400.0 ng/band and 50.0-550.0 ng/band for IVA and MET; respectively. ICH guidelines were followed in respect to linearity and range, accuracy, precision and selectivity, limit of detection (LOD), limit of quantitation (LOQ) and robustness. The analytical eco-scale, green analytical procedure index (GAPI) and analytical greenness metric tools were used to assess the suggested method. The quantitative proposed method results showed there was no statistically significant difference at 95% confidence when compared to the reported method of high performance liquid chromatography (HPLC).

Development of Green HPTLC method for simultaneous determination of a promising combination Tamsulosin and Mirabegron: stability-indicating assay was examined.

Recently, mirabegron has been added to tamsulosin to treat overactive bladder in men with benign prostatic hypertrophy. A Rapid, selective, sensitive, and green high-performance thin-layer chromatography (HPTLC) approach was developed for the simultaneous determination of tamsulosin (TAM) and mirabegron (MIR) in pure and laboratory-prepared mixture. Complete separation was obtained on silica gel F254 using the solvent system methanol-ethyl acetate-ammonia (3:7:0.1, v/v). Short-wave ultraviolet light at 270 nm was used to view the chromatographic bands. For MIR and TAM, the suggested technique revealed compact spots with retention factor Rf values of 0.42 and 0.63, respectively. Within concentration ranges of 0.15-7.5 µg/band and 0.05-2.5 µg/band, good linearity was observed, with mean percentage recoveries of 100.04 ± 0.56 and 99.98% ± 0.95 for MIR and TAM, respectively. Green assessment of the developed HPTLC technique was estimated using different green analytical chemistry metrics such as Analytical eco-scale Analytical GREEness (AGREE), and Green Analytical Procedure Index (GAPI) metrics. The proposed method was effectively used as a stability-indicating assay to assess the presence of MIR and TAM in the pharmaceutical dosage form in the presence of their degradation product. The statistical analysis showed high precision and accuracy.

Highly sensitive spectrofluorimetric method for the determination of the genotoxic methylglyoxal in glycerol-containing pharmaceuticals and dietary supplements.

Methylglyoxal (MGO) is a genotoxic α-dicarbonyl compound. Recently, it was found to be formed in glycerol preparations during storage through auto-oxidation. A simple fluorimetric determination of the carcinogenic degradation product of glycerol, MGO, was developed and validated. The proposed method is based on the derivatization of MGO with 4-carbomethoxybenzaldehyde (CMBA) and ammonium acetate to yield a fluorescent imidazole derivative that can be measured at 415 nm after excitation at 322 nm. The optimized conditions were determined to be 0.2 M CMBA, 1.0 M ammonium acetate and a reaction time of 40 min at 90°C using ethanol as diluting solvent. The linear range was 10.0-200.0 ng/ml. Detection and quantification limits were 2.22 and 6.72 ng/ml, respectively. The proposed method was validated according to International Council for Harmonisation (ICH) guidelines and compared with the reported method and no significant difference was found. It was successfully applied for the determination of MGO in six different glycerol-containing pharmaceutical preparations and dietary supplements.

Spectrofluorimetric determination of selected genotoxic impurities in pharmaceutical raw materials and final products.

A green spectrofluorimetric method was introduced for the determination of selected genotoxic impurities; 2-aminopyridine and 3-aminopyridine in different pharmaceutical raw materials and dosage forms. The method relied on the native fluorescence of these impurities in acidic medium. The experimental conditions were carefully studied and optimized, and the method was validated according to International Council on Harmonisation (ICH) guidelines. The linear range for both analytes was 2.50-100 ng/mL with good determination coefficients of 0.9995 and 0.9992 and detection limits of 0.62 ng/mL and 0.74 ng/mL for 2-aminopyridine and 3-aminopyridine, respectively. The method was successfully applied for determination of 2-aminopyridine and 3-aminopyridine in four active pharmaceutical ingredients and nine dosage forms with satisfactory percentage recoveries and without interference from co-formulated excipients. Analytical performance of the proposed method was comparable to that of the reported methods; hence, the proposed method can be used as a simple and low-cost alternative in quality control laboratories.

Novel Application of Pentabromobenzyl Column for Simultaneous Determination of Eight Antifungal Drugs Using High-performance Liquid Chromatography.

AIM: A new, accurate and sensitive reversed-phase high-performance liquid chromatography (RP-HPLC) as an analytical method for the quantitative determination of eight antifungal drugs in spiked human plasma has been described optimized and validated. MATERIALS AND METHODS: The analyzed compounds were voriconazole (VOR), luliconazole (LUL), clotrimazole (CLO), tioconazole (TIO), posaconazole (POS), ketoconazole (KET), sertaconazole (SER) and terconazole (TER). RESULTS: The separation of the analyzed compounds was conducted using a novel pentabromobenzyl column known as COSMOSIL PBB-R (150 mm × 4.6 mm I.D., particle size 5 µm). The analysis of the studied drugs was determined within 14 min using a diode array detector and the mobile phase consisted of: 10 mM potassium dihydrogen phosphate buffer (pH 2.1): Methanol (2: 98 v/v). A linear response was observed for all compounds in the range of concentration studied. Sample preparation was done through liquid-liquid extraction using diethyl ether. CONCLUSION: This proposed method was validated in terms of linearity, limit of quantification, limit of detection, accuracy, precision and selectivity. The method was successfully applied for the determination of these drugs in their pharmaceutical formulations and in human plasma samples.

Detection and quantification of warfarin in pharmaceutical dosage form and in spiked human plasma using surface enhanced Raman scattering.

Analytical approaches for the quantitation of warfarin in plasma are high in demand. In this study, a novel surface enhanced Raman scattering (SERS) technique for the quantification of the widely used anticoagulant warfarin sodium in pharmaceutical dosage form and in spiked human plasma was developed. The colloidal-based SERS measurements were carefully optimized considering the laser wavelength, the type of metal nanoparticles, their surface functionalization and concentration as well as the time required for warfarin to associate with the metal surface. Poly(diallyldimethylammonium chloride) coated silver nanoparticles (PDDA-AgNPs) were established as a substrate which greatly enhanced the weak warfarin Raman signal with high reproducibility. The limit of detection was calculated in both water and human plasma to be 0.56 nM (0.17 ngmL-1) and 0.25 nM (0.08 ngmL-1) respectively, with a high degree of accuracy and reproducibility. The proposed method is simple, economical, and easily applied for routine application requiring only small plasma samples and also could be potentially useful for pharmacokinetic research on warfarin.

Stability-indicating micellar enhanced spectro-fluorometric determination of Daclatasvir in its tablet and spiked human plasma.

A fast, simple and sensitive micellar enhanced spectrofluorimetric method is performed for the determination of Daclatasvir dihydrochloride (DAC) in its pharmaceutical dosage form and in spiked human plasma. The fluorescence intensity (FI) was measured at 367 nm after excitation at 300 nm. In aqueous solution, the FI of DAC was greatly enhanced by >110% in the presence of sodium dodecyl sulphate (SDS). The detection method was linear over the range of 12.93 to 161.60 ng/mL, with a limit of detection of 1.75 ng/mL. The proposed method was successfully applied to the determination of DAC in its pharmaceutical dosage form and the mean % recovery of DAC in spiked human plasma was 95.42 ±â€¯2.52. The developed methodology was also extended to stress studies of DAC after exposure to different forced degradation conditions including acidic, alkaline, photolytic, thermal and oxidative environments.

Optimized polydopamine coating and DNA conjugation onto gold nanorods for single nanoparticle bioaffinity measurements.

Gold nanorods (NRs) have attracted a great deal of interest for a variety of biomedical and sensing applications. However, developing robust methods for biofunctionalizing NRs has continued to be challenging, especially for NR-DNA conjugates. This is due to the presence of cetyltrimethylammonium bromide (CTAB), which plays an essential role in controlling the anisotropic particle growth. In this article, we systematically explore the growth of a polydopamine (PDA) layer on a range of NR surfaces, comparing different polyelectrolyte and alkanethiol coatings as well as direct CTAB displacement. This revealed that the PDA layer thickness and growth rate is strongly dependent on the underlying nanorod functionalization chemistry and allowed us to establish a preferred route for the creation of stable, non-aggregated suspensions of PDA-coated NRs. The utility of this platform was then demonstrated by self-assembling packed monolayers of single-stranded DNA on the outer surface. Both the surface attachment and bioactivity of the resulting NR-DNA conjugates was then demonstrated by performing bulk solution and single nanoparticle imaging fluorescence measurements.