Search

A novel sedative/hypnotic drug called suvorexant (SUV) is advised for treating insomnia. From a forensic standpoint, it is important medicine because of its sedative/hypnotic and depressing effects. There are no green "high-performance thin-layer chromatographic (HPTLC)" techniques for measuring SUV in the literature. Therefore, this study aims to develop and validate a reverse-phase HPTLC approach that indicates green stability for SUV measurement in commercially available tablet dosage forms. SUV was detected at 255 nm in wavelength. The suggested SUV analysis approach's greenness was assessed using the "analytical eco-scale (AES), ChlorTox, and analytical GREEnness (AGREE)" tools. The current SUV analysis method showed linearity in the 10–1200 ng/band range. Furthermore, the SUV analytical method was robust, accurate (% recoveries = 98.18–99.30), sensitive (LOD = 3.32 ng/band and LOQ = 9.98 ng/band), precise (% CV = 0.78–0.94), and environmentally friendly. The "AES, total ChlorTox, and AGREE" scales were derived to be 93, 0.96 g, and 0.88, respectively, using the current SUV analytical method, demonstrating an exceptional greenness profile. SUV was shown to be suitably unstable under oxidative degradation conditions and suitably stable under acid, base, and heat degradation conditions. Furthermore, the SUV analytical method's stability-indicating component identified SUV in the presence of its breakdown products. It was observed that marketed SUV tablet brands A and B contained, respectively, 98.18 and 101.32% of SUV. The findings of the study indicated that SUV in marketed tablet dosage forms may be monitored on a regular basis with the use of the current green HPTLC methodology. [ABSTRACT FROM AUTHOR]

Novel, simple, accurate and reliable Reverse Phase High-Performance Thin-Layer Chromatographic (RPHPTLC) method for analysis of Agomelatine (AGM) in bulk and tablet formulation have been developed and validated. The method was reverse phase chromatography performed on RP-18 Silica gel F254S TLC plates, with methanol: water (80: 20 %, v/v) as mobile phase. HPTLC quantitation of AGM was done by TLC-densitometry at 276 nm. The quantitation by HPTLC method was performed over the concentration range of 500-3000 ng/band for AGM with a high correlation coefficient (R2 = 0.999). The HPTLC method resulted into a compact and well resolved band for AGM at retention factor (Rf) of 0.43 ± 0.02. The limit of detection and limit of quantification were found to be 5.85 ng and 17.73 ng for RP-HPTLC, respectively. The accuracy of the proposed method was determined by recovery studies and found to be 99.23 to 99.98%. The proposed method is applicable to routine analysis of AGM in bulk and tablet formulations. The proposed method was validated according to various ICH parameters like linearity, accuracy, precision, specificity, limits of detection and limits of quantification. [ABSTRACT FROM AUTHOR]

The greener “high-performance thin-layer chromatography (HPTLC)” methods for apremilast (APM) analysis in pharmaceutical products and biological fluids are not currently available in the literature. Accordingly, this study involves the development and validation of a rapid, simple, economical, and greener reversed-phase HPTLC methodology for the estimation of APM in prepared nanoparticles (NPs), nanoemulsion, and marketed tablets. The estimation of APM was conducted using “RP-18 silica gel 60 F254S HPTLC plates” as the stationary phase. The combination of ethanol/water (65:35, v/v) was used as the greener mobile phase for APM analysis. The greenness of the method was predicted using three different approaches, namely Analytical Eco-Score (AES), ChlorTox, and the Analytical GREENness (AGREE) approaches. The λmax = 238 nm was used for the APM detection. By contrasting its single band at Rf = 0.61 ± 0.01 with those of pure APM, the HPTLC peaks for APM in an prepared NP formulation, nanoemulsion, and marketed tablets were identified. In the concentration range of 100–700 ng/band, the proposed analytical methodology was linear. The values of AES, ChlorTox, and AGREE were determined to be 93, 0.66 g, and 0.89, respectively, demonstrated an outstanding greener profile for the existing method. The amount of APM in the tablet, NP formulation, and nanoemulsion was found to be 98.40, 101.60, and 99.37 %, respectively. According to the findings of validation tests and pharmaceutical analysis, the suggested analytical technique could be successfully applied for the routine examination of APM in marketed tablets and laboratory generated nanoformulations.

The greener "high-performance thin-layer chromatography (HPTLC)" methods for apremilast (APM) analysis in pharmaceutical products and biological fluids are not currently available in the literature. Accordingly, this study involves the development and validation of a rapid, simple, economical, and greener reversed-phase HPTLC methodology for the estimation of APM in prepared nanoparticles (NPs), nanoemulsion, and marketed tablets. The estimation of APM was conducted using "RP-18 silica gel 60 F254S HPTLC plates" as the stationary phase. The combination of ethanol/water (65:35, v/v) was used as the greener mobile phase for APM analysis. The greenness of the method was predicted using three different approaches, namely Analytical Eco-Score (AES), ChlorTox, and the Analytical GREENness (AGREE) approaches. The λ max = 238 nm was used for the APM detection. By contrasting its single band at R f = 0.61 ± 0.01 with those of pure APM, the HPTLC peaks for APM in an prepared NP formulation, nanoemulsion, and marketed tablets were identified. In the concentration range of 100–700 ng/band, the proposed analytical methodology was linear. The values of AES, ChlorTox, and AGREE were determined to be 93, 0.66 g, and 0.89, respectively, demonstrated an outstanding greener profile for the existing method. The amount of APM in the tablet, NP formulation, and nanoemulsion was found to be 98.40, 101.60, and 99.37 %, respectively. According to the findings of validation tests and pharmaceutical analysis, the suggested analytical technique could be successfully applied for the routine examination of APM in marketed tablets and laboratory generated nanoformulations. [ABSTRACT FROM AUTHOR]

For the last several years, searching of new xanthone derivatives (XDs) with potential pharmacological activities has remained one of the main areas of interest of our group. The optimization of biological activity and drug-like properties of hits and leads is crucial at early stage of the drug discovery pipeline. Lipophilicity is one of the most important drug-like properties having a great impact in both pharmacokinetics and pharmacodynamics processes. In this work, we describe the lipophilicity of a small library of bioactive XDs, previously synthesized by our group, using different methods: computational, vortex-assisted liquid–liquid microextraction coupled with high-performance liquid chromatography (VALLME-HPLC), reversed-phase high-performance thin layer chromatography (RP-HPTLC), reversed-phase high-performance liquid chromatography (RP-HPLC), and biomembrane model by the partition between micelles and aqueous phase. The different results obtained by the used methods were compared and discussed. The methodologies and data gathered in this study will expand the investigation of lipophilicity of XDs, an important class of compounds in medicinal chemistry. [ABSTRACT FROM AUTHOR]

Voriconazole is used as an antifungal agent. A new rapid, simple, economical and environmental friendly Reversed -Phase High-Performance Thin-Layer Chromatography (RP-HPTLC) has been developed and validated for quantitative determination of voriconazole in bulk and in cream formulation. RP-HPTLC separation was performed on aluminium plates precoated with silica gel 60RP-18F-254S as the stationary phase using Acetonitrile: Water (60:40% v/v) as mobile phase. Quantification was achieved by densitometric analysis at 257 nm over the concentration range of 200–1200 ng/band. The method was found to give compact and well resolved band for Voriconazole at Retention factor (Rf) 0.48 ± 0.02. The linear regression analysis data for calibration graph showed good linear relationship with r2 = 0.999. The method was validated for precision, recovery, robustness, ruggedness and sensitivity as per International conference on Harmonization (ICH) guidelines. The Limit of Detection (LOD) and Limit of Quantification (LOQ) were found to be 19.99 ng and 60.60 ng, respectively. The proposed developed RP-HPTLC method can be applied for identification and quantitative determination of Voriconazole in bulk and in cream formulation.

Lafutidine (LTD) is a histamine H2 receptor antagonist, with anti-ulcer and mucosal protective activity. A sensitive and selective stability-indicating reversed- phase high -performance thin-layer chromatography (RP-HPTLC)/Densitometry method is suggested for the determination of LTD in the presence of its acid, alkaline, oxidative and dry heat degradation products. Stress testing of LTD was done according to the International Conference on Harmonization (ICH) guidelines in order to validate the stability-indicating power of the analytical procedures. Stress testing demonstrated that LTD underwent acid, alkaline, oxidative and dry heat degradation; on the other hand, it showed stability towards neutral and photo degradation. Chromatography was performed on aluminum-backed silica gel 60 RP-18 F254 S plates with Methanol: Water: Triethylamine 8: 2: 0.5 (v/v) as mobile phase. Densitometric scanning was performed at 276 nm. The system gave compact bands for LTD (Rf 0.67 ± 0.02). Linear regression analysis data for the calibration plots discovered a good linear relationship with r2 > 0.99 in the working concentration range 500 to 3000 ng per band. The limits of detection and quantification were 23.51 ng and 71.26 ng, respectively. The developed method can routinely be used for analysis of LTD in bulk and pharmaceutical formulations.

A simple, rapid, and precise RP-HPTLC method for analysis of Prednisolone acetate and Moxifloxacin hydrochloride in their eye drop dosage forms has been developed and validated. Chromatography was performed on silica gel 60 RP-18F254S plates with Methanol:Water:Triethylamine 7:3:0.3 (v/v) as mobile phase. Detection was performed at 274 nm. The Rfvalues for Prednisolone acetate and Moxifloxacin hydrochloride were found to be 0.50 ± 0.02 and 0.72 ± 0.02, respectively. Regression plots revealed good linear relationships in the concentration ranges 600–3600 ng/band for Prednisolone acetate and 300–1800 ng/band for Moxifloxacin hydrochloride. When accuracy was checked by conducting recovery studies the % recoveries were ranging from 100.97% to 102.03% (Prednisolone acetate) and 100.49% to 101.25% (Moxifloxacin hydrochloride), respectively. The amount of Prednisolone acetate and Moxifloxacin hydrochloride estimated in marketed formulation were 99.22% and 101.07%, respectively. [ABSTRACT FROM AUTHOR]

Abstract: A highly sensitive and selective thin layer chromatographic (TLC) method was developed for simultaneous determination of catecholamines and their related drugs using a new detection method and digital image processing of chromatographic plates. For the quantitative evaluation of the investigated compounds, the chromatographic separation was followed by spraying the plate with 0.02% solution of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH ) in ethanol. The BioDit Thin Layer Chromatography (TLC) Scanner device and advanced specific software (ImageDecipher-TLC, Sorbfil TLC Videodensitometer and JustTLC) were used for the detection and quantification of chromatographic spots. For an accurate determination, the RGB colored images of the bright-white spots detected against a purple background were inverted and processed after their conversion into green scale. The results showed a strongly linear correlation between area (R 2>0.99) and volume (R 2>0.99) of spots and concentration of investigated compounds in all cases. The limit of detection (LOD) and the limit of quantification (LOQ) were below 49.3ng/spot and 69.6ng/spot respectively in all cases. The evaluation of the method was performed using different pharmaceutical samples spiked with the investigated amines and validated with respect to accuracy and precision. [Copyright &y& Elsevier]

A reverse phase high-performance thin-layer chromatography (RPHPTLC) method was developed for determination of vitexin, hyperoside, vitexin-2"-O-rhamnoside, quercetin, and apigenin in the Crataegus oxyacantha extract. The method employed precoated plate of RP-18 silica gel 60F254 as the stationary phase with acetonitrile-methanol-water-formic acid (10:10:20:0.05, v/v) as mobile phase, and densitometric determination was carried out at wavelength 254 nm in reflection/absorption mode. The linear regression analysis data for the calibration plots showed linear relationship (r) from 0.9985 to 0.9992. The method was validated for accuracy, precision, and robustness. The limits of detection and quantification were in the range of 100-300 ng and 310-960 ng, respectively, for analytes. The method is reproducible and convenient for quantitative analysis of these flavonoids in the leaves of C. oxyacantha. This is the first report of simultaneous densitometry quantification of major bioactive constituents in C. oxyacantha by developed and validated RP-HPTLC method. The change in the content of bioactive constituents with growth of the plant was also examined in leaf samples collected for 2 years. [ABSTRACT FROM AUTHOR]

Abstract: A novel, easy, and cheap technique for preliminary quantitative evaluation of antiradical activity, based on HPTLC, has been proposed. This method combines chromatographic separation of polar compounds, present in plant extracts, with data analysis by means of image processing software. Bleaching of the purple DPPH colour, caused by substances with antiradical activity, was observed and recorded using a photo camera. ImageJ, a free and open source image processing program was used for quantitative measurements. For evaluation of assay efficiency, the antiradical activity of rose flower extracts (from Rosa rugosa Thunb.) was expressed as Standard Activity Coefficients (SACs), which are relative measures of the activity to the four well known antioxidants; i.e., quercetin, gallic acid, protocatechuic acid, and Trolox. The method uses small amounts of free radical and is easily applicable – only a digital camera with freely available open source software is required. [Copyright &y& Elsevier]

A simple, rapid, specific, and accurate reverse-phase high-performance thin-layer chromatography (RP-HPTLC) method was developed and validated for simultaneous quantification of levodopa, carbidopa, and entacapone in their combined dosage form. Due to the structural similarity between levodopa and carbidopa, and vast difference in their polarity with that of entacapone, it is very challenging to carry out the simultaneous estimation of all three drugs together. In the developed method, chromatography was performed on TLC plates with precoated silica gel 60 RP-18 F254 using acetonitrile-n-butanol-water-triethylamine (0.5:9.5:1:0.001, v/v/v/v), pH adjusted to 3.6 with o-phosphoric acid, as the mobile phase. Densitometric evaluation was performed at 282 nm. The RF values were 0.46, 0.64, and 0.87 for levodopa, carbidopa, and entacapone, respectively. The polynomial regression data for the calibration plots showed good linear relationship in the concentration range 300-1500 ng per spot for levodopa, 200-1000 ng per spot for carbidopa, and 200-2000 ng per spot for entacapone. The suitability of this HPTLC method for quantitative determination of drugs was proved by validation in accordance with the requirements of the International Conference on Harmonization (ICH) guidelines (Q2B). [ABSTRACT FROM AUTHOR]

Retention indices for some precursors of peraza crown ethers were determined by reversed phase high-performance thin layer chromatography on RP-18 plates with methanol-water in different volume proportions as mobile phase. The Log P values for the same compounds were calculated using different computer programs: SciQSAR, SciLogP, Chem3D Ultra 8.0, XLOGP (based on atom contributions), Chemaxon and KOWWIN (based on atom/fragment contributions), cLogP (based on fragmental contributions), ALOGPS and IAlogP (based on atom-type electrotopological-state indices and neural network modeling). A comparative study concerning lipophilic parameters (R, b and ϕ0) and computed partition coefficients has been developed. Taking into account the correlation coefficients between determined and calculated Log P values, it seems that R and b are less suitable than ϕ for estimating lipophilicity of the compounds investigated, and cLogP and ALOGPS provide the best correlations with experimental values. [ABSTRACT FROM AUTHOR]

Silica gel plates impregnated with a variety of oils including vegetable oils (olive, sunflower and corn oil) and synthetic oils (trioctylamine and paraffin oil) were evaluated and compared with the commercially available reversed-phases TLC plates (RP-18, RP-18W, and CN). A series of selected lipophilic vitamins was employed to evaluate the suitability of oils as reversed-phases for TLC and to provide different lipophilicity indices: R, scores corresponding to the first principal component of R and/or R the arithmetic mean of R and R values obtained with solvent mixture containing various concentrations of methanol in water. The retention results were excellent ( r > 0.98) and allowed accurate estimation of lipophilicity of selected vitamins and to ranking the lipophilicity of oils when comparing with chemically bonded phases. Concerning the lipophilicity scale of vegetable oils, it is worth noting that corn oil presents the highest lipophilicity, closely followed by the olive and sunflower oils. [ABSTRACT FROM AUTHOR]

Abstract: The chromatographic behavior of some artificial and natural sweeteners was established by reverse phase high performance thin-layer chromatography (RP-HPTLC) on RP-18, RP-18W, RP-8, CN and NH2 stationary phases. The mobile phases were mixtures of acetonitrile–water in different proportions of volume, chosen to create a suitable migration during the chromatographic process. The lipophilicity was described through different chromatographic descriptors such as R M0, mean of R M (mR M), and scores of R M values corresponding to the first principal component (PC1/R M). In addition, scores and loadings resulting from covariance matrix of retention data enable new information about similarity and differences of investigated compounds and between both the stationary and mobile phases. The experimental lipophilicity indices estimated from retention data are directly correlated with the computed values, via computer software and internet module, at a high significant statistical level. [Copyright &y& Elsevier]

The selected steroid compounds (androsterone, epi-androsterone, dehydroepi-androsterone, testosterone, stigmasterol, β-sitosterol, estradiol, hydrocortisone, and cholesterol) were investigated with the use reversed phase high performance thin layer chromatography on RP18W plates (#1.14296, E. Merck), using methanol-water, acetonitrile-water in different volume compositions as a mobile phases. The chromatographic parameters of lipophilicity (RMW) of the studied steroids were determined. Topological indexes based on the adjacency matrix: Gutman (M, Mν), Randic (oχν, 1χν, oχν, and 1χν), based on distance matrix: Rouvray (R), Wiener (W), and Pyka (A, oB, and 1B), and also based on information theory (ISA and ISA) and theoretical partition coefficients (Alog Ps, IAlog P, Clog P, log PKowwin, xlog P, and miLog P) for investigated steroids were calculated. It was found that lipophilicity determined chromatographically (RMW) correlated best with topological indices oχν, 1χν, R, W, A, and 1B. However, theoretical partition coefficient values (Alog Ps, IAlog P, Clog P, log PKowwin, xlog P, and miLog P) correlated best with topological index ISA. [ABSTRACT FROM AUTHOR]

Acids from pentanoic to tricosanoic have been separated using RP-HPTLC, on RP-18 plates with and without a concentrating zone, using methanol-water, ethanol-water and n-propanol-water (90:10, 95:5, and 100:0, v/v) as mobile phases. RF values obtained have been converted into RM values. RM values have been used to calculate and predict the neutralization value, boiling point, melting point, and heat of crystallization of fatty acids investigated. Relationships between selected physiochemical properties of fatty acids and RM values obtained using RP-HPTLC have been described by polynomials of the second degree or linear functions. All described relationships have been characterized by high values of determination coefficients, which were in the range of 93.32÷99.94%. It suggests the possibility of using them to calculate and predict the values of neutralization value, boiling point, melting point, and heat of crystallization of acids investigated. [ABSTRACT FROM AUTHOR]

Nicotinic acid (1) and its derivatives, namely nicotinamide (8), 3-pyridinecarbaldehyde (11), 3-pyridinecarbonitrile (12), 3-pyridylmethanol (13), and methyl 3-pirydyl ketone (14) were investigated by NP-TLC, and RP-HPTLC. The RF values were obtained from the densitometric analysis. The separation factors ΔRF, RFα, and selectivity α were calculated from the RF values. The comparison and characteristic of chromatographic bands of the examined compounds were presented on the basis of calculated resolutions: RS(c), RS(b), RS(h), and RS(a). The resolutions of substances were determined by visual method (RS(c)) and densitometric method (RS(b), RS(h), and RS(a)). It was affirmed that the densitometric method is correct and the standard method to determine the above mentioned parameters. Furthermore, the RS parameter determined by the visual method for two adjacent substances is always larger than determined by the densitometric method. It was affirmed, that the best separation of the studied compounds was obtained by the RP-HPTLC technique on RP18WF254 plates, and by use of dioxane-water in a volume composition of 20:80. However, 3-pyridinecarbaldehyde (11) from 3-pryridinecarbonitrile (12) cannot be separated by the RP-HPTLC technique. It was also affirmed, that adsorption thin-layer chromatography (NP-TLC) in the system of a silica gel 60F254 and the acetone-n-hexane mobile phase in a volume composition of 80:20 provided the optimum conditions for the complete separation of 3-pyridinecarbaldehyde (11) from 3-pryridinecarbonitrile (12). [ABSTRACT FROM AUTHOR]

Acids, from octanoic to octadecanoic, have been separated using RP‐HPTLC, on RP‐18 plates without and with a concentrating zone, using methanol‐water and ethanol‐water (90∶10 and 95∶5, v/v) as mobile phases. RF values obtained have been converted to RM values. RM values have been used to calculate the solubilities in water of fatty acids investigated at different temperatures. Relationships between solubility in water of fatty acids at different temperatures and RM values obtained using RP‐HPTLC have been described by polynomials of third degree or expotential functions. All described relationships have been characterized by high values of determination coefficients, which were in the range of 96.65÷99.97%. This suggests the possibility of using them to calculate and predict the values of solubilities in water of acids investigated. [ABSTRACT FROM AUTHOR]

An homologous series of carboxylic FA, from methanoic to triacontanoic, were characterized by selected structural descriptors based on distance matrix (W, A, 0B, ¹B), adjacency matrix (M, Mv, 0χ, ¹χ, ²χ, 0χv, ¹χv, ²χv F, N2), and information theory (ISA, ĪSA), as well as electrotopological states. Saturated FA, from pentanoic to eicosanoic as well as from heptanoic to tricontanoic acids, were separated by reversed-phase high-performance TEC (RP-HPTLC) using mobile phases of methanol/ water. The relationships existing between experimental partition coefficients (log Pexp), partition coefficients obtained from an Internet database (IAlogP and ClogPTM), and RM values (obtained by means of RP-HPTLC, where RM is the hydrophobicity index) or structural descriptors (based on adjacency matrix: M, Mv, 0χ, ¹χ, ²χ, 0χv, ¹χv, ²χv F, N2 and information theory: ISA, ĪSA) of saturated FA were investigated. Comparison and estimation of the usefulness of RM values and selected structural descriptors for calculating and predicting partition coefficients of saturated FA are the novel components of the work presented. The authors found that both values for RM and structural descriptors can serve for calculating and predicting the partition coefficients of FA investigated; but the selected traditional structural descriptors better describe the partition coefficients than the RM values. [ABSTRACT FROM AUTHOR]

The selected steroid compounds (androsterone, epi‐androsterone, dehydro‐epi‐androsterone, testosterone, stigmasterol, β‐sitosterol, estradiol, hydrocortisone, and cholesterol) were investigated with the use reversed‐phase high performance thin layer chromatography on RP18W plates (#1.14296, E. Merck), using methanol‐water, acetonitrile‐water in different volume compositions as a mobile phase. The chromatographic parameters of lipophilicity (RMW and ϕ0) of the studied steroids were determined. Lipophilic parameters (RMW and ϕ0) were compared both, with measured (logPexp), and calculated partition coefficients (AlogPS, IAlogP, logPKOWIN, xlogP, ClogP, miLogP). Comparing all calculation procedures, generally ClogP and IAlogP are more appropriate for chromatographic parameters of lipophilicity and experimental n‐octanol‐water partition coefficients of studied steroid compounds. The results indicate that chromatographic parameters of lipophilicity may be used as a measure of lipophilicity of the investigated steroid compounds. [ABSTRACT FROM AUTHOR]

The following bile acids: cholic acid (C), glycocholic acid (GC), glycodeoxycholic acid (GDC), chenodeoxycholic (CDC), deoxycholic acid (DC), lithocholic acid (LC), and glycolithocholic acid (GLC) were investigated with the use of reversed phase thin-layer chromatography on RP2 plates (E. Merck, # 1.13726) using methanol-water, organic mixture (acetonitrile-methanol 50:50, v/v)-water, acetone-water, dioxane-water in different volume compositions as mobile phases. The chromatographic parameters of lipophilicity (R MW and f 0 ) of studied bile acids were determined. Lipophilic parameters (R MW and f 0 ) were compared, both with measured partition coefficients (logP exp ) and calculated ones (AlogP S , IAlogP, logP KOWIN , xlogP, clogP, logP Rekker ). The most significant correlation was found between R MW and f 0 lipophilic parameters and logP KOWIN values. IAlogP correlates with the a/m lipophilic parameters slightly more poorly than logP KOWIN does. The values of R MW and f 0 lipophilic parameters obtained on both, RP2 and RP18W plates with the use of the a/m mobile phases, indicate that the investigated bile acids may be listed in order of decreasing lipophilicity as follows: LC>DC˜CDC˜GLC>C˜GDC>GC. [ABSTRACT FROM AUTHOR]

Selected bile acids: cholic acid (C), glycocholic acid (GC), glycodeoxycholic acid (GDC), chenodeoxycholic acid (CDC), deoxycholic acid (DC), lithocholic acid (LC), and glycolithocholic acid (GLC) were investigated with the use of reversed phase high performance thin-layer chromatography on RP18W (E. Merck, #1.14296), RP18 (E. Merck, #1.05914), RP2 (E. Merck, #1.13726), and CNF 254 (E. Merck, #1.12571) plates using methanol–water, organic mixture (acetonitrile–methanol 50:50, v/v)–water, acetone–water, dioxane–water, and acetonitrile–phosphate buffer (pH 4.60) as mobile phases, in different volume compositions. The obtained separations were carried out on the basis of separation factors values ?R F and R S . None of the applied chromatographic conditions enabled completion of the separation of all examined bile acids. Five neighboring bile acids, i.e., LC/DC, CDC/GLC, GLC/C, C/GDC, GDC/GC, were separated only when CNF 254 plates and the mobile phase acetone–water, 50:50; v/v were used. The biggest problem was to separate DC from CDC. These bile acids were separated only on RP2 plates by using methanol–water, 65:35, v/v as a mobile phase. [ABSTRACT FROM AUTHOR]

Fatty acids from octanoic acid to octadecanoic acid have been separated on RP-18 plates with and without a concentrating zone using methanol–water, ethanol–water, and n-propanol–water as mobile phases. The cluster analysis for comparison of RM parameters of investigated acids for chromatographic conditions used was proposed. Comparison of differences between RF values showed that acids from nonanoic to octadecanoic are separated on the longest distance, using as mobile phase methanol–water in a volume ratio of 95 + 5 and on RP-18 plates with and without concentrating zone. Moreover, resolution factor values (RS) calculated suggest that better separations of acids from octanoic to octadecanoic were obtained on RP-18 plates with a concentrating zone and methanol–water (95 + 5, v/v) as mobile phase. [ABSTRACT FROM AUTHOR]

Voriconazole is used as an antifungal agent. A new rapid, simple, economical and environmental friendly Reversed -Phase High-Performance Thin-Layer Chromatography (RP-HPTLC) has been developed and validated for quantitative determination of voriconazole in bulk and in cream formulation. RP-HPTLC separation was performed on aluminium plates precoated with silica gel 60RP-18F- 254 S as the stationary phase using Acetonitrile: Water (60:40% v/v ) as mobile phase. Quantification was achieved by densitometric analysis at 257 nm over the concentration range of 200–1200 ng/band. The method was found to give compact and well resolved band for Voriconazole at Retention factor ( R f ) 0.48 ± 0.02. The linear regression analysis data for calibration graph showed good linear relationship with r 2 = 0.999. The method was validated for precision, recovery, robustness, ruggedness and sensitivity as per International conference on Harmonization (ICH) guidelines. The Limit of Detection (LOD) and Limit of Quantification (LOQ) were found to be 19.99 ng and 60.60 ng, respectively. The proposed developed RP-HPTLC method can be applied for identification and quantitative determination of Voriconazole in bulk and in cream formulation. [ABSTRACT FROM AUTHOR]