CYCLOSPORIN A AFFECTS THE PROLIFERATION PROCESS IN NORMAL HUMAN DERMAL FIBROBLASTS.

Cyclosporin A is an immunosuppressant drug that is used not only in solid transplant rejection, but also in moderate and severe forms of psoriasis, pyoderma, lupus or arthritis. Serious side effects of the drug such as skin cancer or gingival hyperplasia probably start with the latent proliferation process. Little is known about the influence of cyclosporin A on molecular signaling in epidermal tissue.

EVALUATION OF LIPOPHILIC PROPERTIES OF BETAMETHASONE AND RELATED COMPOUNDS.

The lipophilicity (R(MW)) of betamethasone and its four related compounds: betamethasone-17,21-dipropionate, betamethasone-17-valerate, betamethasone-21-valerate and also betamethasone disodium phosphate was determined by reversed phase HPTLC and various mobile phase systems (methanol-water, dioxane-water and acetonitrile-water). The chromatographic lipophilicity parameters obtained for all examined compounds using abovementioned mobile phases onto three chromatographic plates (RP-2F254, RP-8F254, RP-18WF254) were compared with the theoretical partition coefficients which have been calculated by different computing programs: AlogPs, AClogP, AlogP, MlogP, KOWWIN, xlogP2, xlogP3, logP(ChemDraw) as well as with logP measured by shake-flask method. The results of this work demonstrate that regardless of applied method the greatest similarity in lipophilic properties show betamethasone-17-valerate, betamethasone-21-valerate and also betamethasone 17,21-dipropionate.

LIPOPHILICITY ASSESSMENT OF SPIRONOLACTONE BY MEANS OF REVERSED PHASE LIQUID CHROMATOGRAPHY AND BY NEWLY DEVELOPED CALCULATION PROCEDURES.

The parameters of lipophilicity of spironolactone (a single member of steroids group), which is widely applied as diuretic and antihypertensive agent, were experimentally determined by reversed-phase TLC and HPLC methods as well as calculated using different computer programs and also by a novel mode based on topological indices. Various stationary phases, such as RP-18WFA4254, RP-2F254, RP-18F254 and also different binary solvent systems composed of organic modifier (e.g.

Application of chemometric analysis based on physicochemical and chromatographic data for the differentiation origin of plant protection products containing chlorpyrifos.

The aim of this study was to investigate the similarities and dissimilarities between the pesticide samples in form of emulsifiable concentrates (EC) formulation containing chlorpyrifos as active ingredient coming from different sources (i.e., shops and wholesales) and also belonging to various series.

Validation of an RPHPTLC-Densitometric Method Using Silica Gel 60 RP18WF254 for Simultaneous Determination of Nicotinamide in Selected Pharmaceutical Formulations.

This research study describes the applicability of silica gel 60 RPW18F254 plates for the development and validation of new, simple, economic, accurate, and precise RPHPTLC-densitometric method suitable for the quantification of nicotinamide (as Vitamin PP) in three marketed preparations. The mobile phase used was methanol-water in volume composition 3 : 7. Detection wavelength was 200 nm.

TLC--densitometric method for qualitative analysis of betamethasone and its related compounds in pharmacautical preparations.

A new simple and rapid TLC-densitometric procedure for the separation and identification of betamethasone and its related substances, betamethasone-17,21-dipropionate, betamethasone-17-valerate, betamethasone-21-valerate and also betamethasone disodium phosphate was developed. One of the chromatographic systems proposed in this study, which has been satisfactory applied in separation of four pairs of examined compounds was silica gel 60F254 (E. Merck, Art.

Application of various methods to determine the lipophilicity parameters of the selected urea pesticides as predictors of their bioaccumulation.

Different lipophilicity procedures including a newly developed (based on Ościk's equation) was applied in order to compare various urea pesticides with herbicidal and also insecticidal activity, such as monolinuron, chlorotoluron, diuron, isoproturon, linuron, dimefuron, diflubenzuron, teflubenzuron and lufenuron. Lipophilicity parameters (RMWS and RMW0) of nine examined pesticides were determined on the chromatographic plates RP-8F254 with the use of methanol-water as a mobile phase. Similarity analysis enabled to group all examined pesticides depending on their lipophilic character and allowed to perform a more objective comparison of different lipophilicity parameters obtained for investigated compounds by means of thin-layer chromatography and by the use of computational methods.

Detection progress of selected drugs in TLC.

This entry describes applications of known indicators and dyes as new visualizing reagents and various visualizing systems as well as photocatalytic reactions and bioautography method for the detection of bioactive compounds including drugs and compounds isolated from herbal extracts. Broadening index, detection index, characteristics of densitometric band, modified contrast index, limit of detection, densitometric visualizing index, and linearity range of detected compounds were used for the evaluation of visualizing effects of applied visualizing reagents. It was shown that visualizing effect depends on the chemical structure of the visualizing reagent, the structure of the substance detected, and the chromatographic adsorbent applied.

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 60F254 plates.

Validation thin layer chromatography for the determination of acetaminophen in tablets and comparison with a pharmacopeial method.

Adsorption thin layer chromatography (NP-TLC) with densitometry has been established for the identification and the quantification of acetaminophen in three leading commercial products of pharmaceutical tablets coded as brand: P1 (Product no. 1), P2 (Product no. 2), and P3 (Product no.

Application of TLC, HPLC and GC methods to the study of amino acid and peptide enantiomers: a review.

Amino acids are very important organic compounds in nature. The biological activity of amino acids depends mainly on their stereoisomeric configuration (d- or l-). Thus, the stereochemical analysis of amino acids and peptides is an important aspect of their characterization.

Topological indexes and QSRR methodology in pharmaceutical and chemical analysis.

This paper presents an assessment of the possibility of using topological indexes and related structural descriptors in TLC, HPLC, GC, micellar electrokinetic capillary chromatography (MEKC), and capillary zone electrophoresis (CZE) techniques. Every work quoted is a new aspect of the use of topological indexes. Data from the scientific literature indicate that the topological indexes discussed can be used to predict and describe retention and lipophilic parameters obtained by TLC, HPLC, GC, MEKC, and CZE for different classes of organic compounds including drugs.

Densitometric determination of arbutin in cowberry leaves (Vaccinium vitis idaeae).

Densitometry was used for quantitative determination of arbutin (Vaccinium vitis idaeae) in leaves of cowberry collected from region of Suwalszczyzna, Poland. Arbutin was extracted using methanol. Chromatography was performed on glass TLC plates with layers of silica gel.

Lipophilicity of thiobarbiturates determined by TLC.

Lipophilicty of 29 thiobarbituric acid derivatives were assessed by reversed-phase thin-layer chromatography using methanol: water mixtures as a mobile phase. A linear relationship was found between RM values and methanol concentrations in the mobile phase. The retention parameter, RM0, was related to theoretical partition coefficients calculated by means of different theoretical procedures (AlogPs, IAlogP, miLogP, logPKowwin, xlogP).

A comparison of theoretical methods of calculation of partition coefficients for selected drugs.

Hundred ninety three drugs of different pharmacological activity were studied. Lipophilicity of a drug is one of the parameters, which influence its biological activity. The n-octanol-water partition coefficients were calculated for these compounds by use of different theoretical procedures (AlogPs, IAlogP, miLogP, ClogP, logP(Kowwin), and xlogP).

Application of structural descriptors for the evaluation of some physicochemical properties of selected bile acids.

Selected bile acids such as: cholic (C), glycocholic (GC), glycodeoxycholic (GDC), chenodeoxycholic (CDC), deoxycholic (DC), lithocholic (LC) and glycolithocholic acids (GLC) were separated by TLC technique. Selected topological indices, based on adjacency and distance matrices, and electrotopological states were calculated for the studied bile acids. Different possibilities of application of structural descriptors to calculate specified physicochemical data of the examined bile acids were found (QSPR).

A comparison of chromatographic separation of selected nicotinic acid derivatives by TLC and HPLC techniques.

The separations of nicotinic acid and its derivatives analyzed by adsorption and reversed phase TLC and HPLC were compared. Results were presented as the dependencies of chromatographic retention parameters of studied compounds on the volume composition [%] of mobile phases. It was shown that there exists the possibility of the separation of compounds into specified groups (adsorption TLC and HPLC) and particular substances within individual groups (reversed phase TLC).

Application of topological indices for prediction of the biological activity of selected alkoxyphenols.

The topological indices based on adjacency and distance matrices, and electrotopological states were calculated for selected meta and para alkoxyphenols. The toxicities of alkoxyphenols on gram-positive M. pyogenes var.

Application of topological indexes for evaluation of the TLC separation of selected essential oil components.

The selected essential oil components (menthol, (+)bomeol, geraniol, linalool, carvone, camphor, (IR)-(-)fenchone) were separated by adsorption thin-layer chromatography using benzene as mobile phase. Investigated terpenes were characterized by selected topological indexes based on the adjacency and distance matrix. From among all the topological indexes counted only Si(o) index (the sum of the distance between the oxygen atom and all the remaining atoms in graph) as well as cluster Randić indexes (4chi(c), and 4chi(v)c) allow for estimation of the chromatograms obtained.