A cost-effective and sensitive TLC-densitometric identification of meloxicam

The influence of different chromatographic conditions and the process of spot visualization on determining the limit of detection as well as quantification (LOD and LOQ) of meloxicam by TLC-densitometric technique was estimated. Of all chromatographic conditions tested, the lowest limiting values, thus the best sensitivity, in the NP-TLC system was achieved on silica gel 60F254 and neutral aluminum oxide plates developed with the mobile phase consisting of ethyl acetate/toluene/n-butylamine (2:2:1, V/V/V). In the case of the RP-TLC method, a mixture of methanol/water (8:2, V/V) enabled densitometric detection of meloxicam at the lowest concentration level on RP-8F254 and RP-18F254 plates. Additionally, the smallest LOD value of meloxicam ensured crystalline violet and gentian violet as visualization agents on silica gel 60F254 and neutral aluminum oxide 150F254 plates, resp. Comparison of the densitometrically obtained spectra of meloxicam drug and its standard after the use of appropriate visualization agents could be a good and cheap alternative tool for the identification of meloxicam as an active pharmaceutical ingredient.

TLC-Densitometric Determination of Five Coxibs in Pharmaceutical Preparations

A class of drugs called coxibs (COX-2 inhibitors) were created to help relieve pain and inflammation of osteoarthritis and rheumatoid arthritis with the lowest amount of side effects possible. The presented paper describes a new developed, optimized and validated thin layer chromatographic (TLC)-densitometric procedure for the simultaneous assay of five coxibs: celecoxib, etoricoxib, firecoxib, rofecoxib and cimicoxib. Chromatographic separation was conducted on HPTLC F254 silica gel chromatographic plates as a stationary phase using chloroform–acetone–toluene (12:5:2, v/v/v) as a mobile phase. Densitometric detection was carried out at two wavelengths of 254 and 290 nm. The method was tested according to ICH guidelines for linearity, recovery and specificity. The presented method was linear in a wide range of concentrations for all analyzed compounds, with correlation coefficients greater than 0.99. The method is specific, precise (%RSD < 1) and accurate (more than 95%, %RSD < 2). Low-cost, simple and rapid, it can be used in laboratories for drug monitoring and quality control.

NOVEL HIGH-PERFORMANCE THIN-LAYER CHROMATOGRAPHIC METHOD FOR SIMPLE, ECONOMICAL, AND RAPID DETERMINATION OF FENOFIBRATE IN BULK AND PHARMACEUTICAL DOSAGE FORM

Objective: A simple, novel, sensitive, and rapid high-performance thin-layer chromatographic (HPTLC) method has been developed and validated for quantitative determination of fenofibrate in bulk and formulations.Methods: The chromatographic development was carried out on HPTLC plates precoated with silica gel 60 F254 using a single solvent dichloromethane as a simple mobile phase. Densitometric detection was carried out at 292 nm.Results: Rf value of drug was found to be 0.33±0.02. The method was validated as per International Conference on Harmonization Guideline with respect to linearity, accuracy, precision, and robustness. The calibration curve was found to be linear over a range of 20–400° ng band−1° with a regression coefficient of 0.999. The method has proved high sensitivity and specificity.Conclusion: Proposed densitometric method was found to be new, simple, and economic for routine quantification of fenofibrate in bulk and pharmaceutical formulation.

Comparative validation of HPLC, densitometric and videodensitometric determination of lamotrigine in pharmaceutical

Simple, sensitive, precise and accurate HPLC, densitometric and videodensitometric methods for determination of lamotrigine in tablet forms were developed and validated. The HPLC method was carried out using a Symmetry C8 column and a mobile phase acetonitrile-phosphate buffer pH 2.80 (25:75, v/v), with a flow rate of 1 mL/min, and UV detection at 210 nm. Ethosuximide was used as the internal standard. Densitometric and videodensitometric analysis was performed on silica gel 60 F254 plates, in horizontal chambers, with methanol-chloroform-ammonia (25%) 1.5:7.5:1, (v/v) as mobile phase. Densitometric detection was performed at 225 nm and at 315 nm, and videodeoscanning at 254 nm. Calibration plots were constructed in the range 0.5-10 μg/spot, with good correlation coefficients r > 0.99 for both methods. The precision and accuracy of all elaborated methods were compared. Finally, the developed methods were applied for the quality control of lamotrigine tablets.

Comparative Analysis of Therapeutically Important Indole Compounds in in vitro Cultures of Hypericum perforatum Cultivars by HPLC and TLC Analysis Coupled with Densitometric Detection

Five indole compounds (5-hydroxy-L-tryptophan, L-tryptophan, indole-3-acetic acid, melatonin, serotonin) and hypericin were identified and quantified in methanolic extracts of shoot cultures of three Hypericum perforatum cultivars (Helos, Elixir, Topas) growing on two variants of Murashige -Skoog medium differing in concentrations of growth regulators (naphthalene-1-acetic acid and 6-benzylaminopurine). Extracts of the aboveground parts of field-grown plants ( Hyperici herba) were also analyzed by HPLC and TLC analysis coupled with densitometric detection. Determination of four compounds was based on our assay described earlier. The methods of determination of 5-hydroxy-L-tryptophan and hypericin were developed and validated in this study. The composition and contents of the metabolites under study differed between the cultivars cultured in vitro and between medium variants containing diverse contents of growth regulators. The contents of individual indole compounds in the biomass from in vitro cultures ranged from 39.6 to 343.2 mg/100 g dry mass. 5-Hydroxy-L-tryptophan was the dominating metabolite (from 78.2 to 343.2 mg/100 g dry mass). Extracts from shoots of the cultivar Helos also contained high contents of serotonin (319.9 and 197.4 mg/100 g dry mass). The contents of indole compounds in Hyperici herba were also diverse (from 7.1 to 55.3 mg/100 g dry mass). 5-Hydroxy-L-tryptophan was the dominating metabolite as well. Hypericin content of Hyperici herba, equaling 12.2 mg/100 g dry mass was from 3.3 to 10 times higher than in extracts from shoots cultured in vitro. The present report is the first analysis of endogenous accumulation of indole compounds in Hyperici herba which involves, apart from melatonin, four other compounds.

Validation of a Thin-Layer Chromatography for the Determination of Hydrocortisone Acetate and Lidocaine in a Pharmaceutical Preparation

A new specific, precise, accurate, and robust TLC-densitometry has been developed for the simultaneous determination of hydrocortisone acetate and lidocaine hydrochloride in combined pharmaceutical formulation. The chromatographic analysis was carried out using a mobile phase consisting of chloroform + acetone + ammonia (25%) in volume composition 8 : 2 : 0.1 and silica gel 60F254plates. Densitometric detection was performed in UV at wavelengths 200 nm and 250 nm, respectively, for lidocaine hydrochloride and hydrocortisone acetate. The validation of the proposed method was performed in terms of specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, and robustness. The applied TLC procedure is linear in hydrocortisone acetate concentration range of3.75÷12.50 μg·spot−1, and from1.00÷2.50 μg·spot−1for lidocaine hydrochloride. The developed method was found to be accurate (the value of the coefficient of variation CV [%] is less than 3%), precise (CV [%] is less than 2%), specific, and robust. LOQ of hydrocortisone acetate is 0.198 μg·spot−1and LOD is 0.066 μg·spot−1. LOQ and LOD values for lidocaine hydrochloride are 0.270 and 0.090 μg·spot−1, respectively. The assay value of both bioactive substances is consistent with the limits recommended by Pharmacopoeia.

Photostability of triazole antifungal drugs in the solid state

The publication is devoted to photostability assessment of four triazole antifungal drugs: fluconazole, itraconazole, posaconazole and voriconazole. The compounds were exposed in the solid state using the whole spectrum of UV-Vis radiation. The analyses were performed using high performance thin layer chromatography (HPTLC) technique with densitometric detection. The results indicates considerable degradation of structurally similar itraconazole and posaconazole which could be clinically significant. After 72 hours of itraconazole irradiation there remain less than 25%, and 60% in case of posaconazole. To a lesser extent photodegradation concern two other compounds with a separate chemical structure: fluconazole and voriconazole. After 72 hours of irradiation there left 75% and 82% of these substances, respectively. The strict dependence between compound photostability and its chemical structure was observed.