Simple and Accurate HPTLC-Densitometric Method for Assay of Nandrolone Decanoate in Pharmaceutical Formulation.

This study reports the development and validation of a new, simple, and accurate high-performance thin-layer chromatography (HPTLC)-densitomeric method for the determination of nandrolone decanoate in a commercially available injection formulation. Chromatographic analysis was performed on glass CN modified silica gel 60F254 plates developed using n-hexane-ethyl acetate in volume ratio 42.5:7.5 as the mobile phase. Densitometric scanning was carried out at the wavelength of 245 nm. This chromatographic system gave compact spot and a symmetrical peak of nandrolone decanoate with retardation factor (RF) value at 0.57 (±0.02). The linearity of this method with the high correlation coefficient of calibration plot ranges from 0.780 to 12.500 µg/spot. The developed method is characterized by good precision (coefficient of variation CV < 2%) and high accuracy close to 100.3% (R = 99.0%). Values of limits of detection and quantification equal to 0.231 and 0.700 µg/spot, respectively, confirm the sensitivity of the developed method. The analysis of the pharmaceutical formulation of nandrolone decanoate indicates drug content of 50.5 mg/mL and 101.0% in relation to the label claim. This is in good agreement with the recommendation of the International Council for Harmonisation (ICH) guidelines as well as the pharmacopoeial requirements. The low CV value (<1%) of nandrolone decanoate content in the tested injection formulation confirms the suitability of the proposed HPTLC-densitometric method for routine control of this compound in examined pharmaceuticals.

Phytochemical standardization of Vasicinein cough syrup by high performance liquid chromatography-densitometry.

The highly oriented modern detection techniques provide a precise and definite tool for investigation in natural medicines. Current study directed the standardization of eminent biomarker Vasicine in a natural cough syrup. A highly accurate and precise method of High-performance thin layer chromatography (HPTLC) has been developed to certify the quantity of vasicine inside the syrup. Ethyl acetate, chloroform, ethanol and ammonia (6:3:1: 1 v/v) were mobile phase for the study. The TLC plate silica gel G60F254 was used with CAMAG Scanner III and CAMAG Linomate 5. The detected Rf value was 0.51 in both sample and reference standard at 254 nm. International conference of Harmonization (ICH) guidelines were followed for the validation of the developed method. Linearity was achieved in the range of 200µg to 1600µg with co-efficient correlation r2=0.9995. Accuracy was found in between 98.9 to 101.4% however precision was good at both inter and intra-day. As per the standardization of ICH, the developed method was found to be reproducible and showed sharp similar peak with high resolution.

À côté calibration - Making optimal use of time and space in quantitative high performance thin layer chromatography.

Quantitative High Performance Thin Layer Chromatography (HPTLC) requires the application of several standards to each plate, reducing the number of actual samples that can be analyzed in a single run. Using pure standard compounds and a selective detection method, the standards for quantitation can be applied besides - à côté - the chromatography area. This frees the sample application space to accommodate the maximal number of sample on each plate. Also, analysis time is spent exclusively on samples, drastically shortening the effective analysis time per sample and increasing sample throughput. Using this new calibration approach, the sample capacity of regular HPTLC methods can be increased or their scope be extended by an additional quantitative analysis. As a limitation, changes to the distribution of samples and standards within the plate as well as interferences from matrix compounds must be observed. We demonstrate the feasibility of this method by complementing an HPTLC method with a quantitative analysis of total anthocyanin content in colored wheat varieties. The quantitation was validated and compared to the conventional photometric analysis. As outcome, the additional photometric analysis could be replaced and rendered unnecessary, saving time, effort and equipment. This approach could also be employed to quantify highly retained substances, which are usually inaccessible for quantitative analysis.

Estimation of yohimbine base in complex mixtures by quantitative HPTLC application.

The indole alkaloid Yohimbine has been used for over two centuries in the treatment of erectly dysfunction. Several formulations containing yohimbine salts, yohimbe bark power or extract are marketed worldwide. Determination of the amount of yohimbine in such formulation is a challenging task due to their complex nature. Extraction followed by acid-base purification resulted in a relatively pure alkaloids containing fractions. The exact amounts of yohimbine free base in different formulations were determined by densitometric HPTLC validated methods using silica gel TLC plates. Standard curve for yohimbine was generated using yohimbine hydrochloride subjected to the same acid-base treatment as the used samples. All formulations found to contain yohimbine though some with less concentration than the labeled amount.

Solar catalysed activity against methyl orange dye, cytotoxicity activity of MCF-7 cell lines and identification of marker compound by HPTLC of Lagerstroemia speciosa.

The investigation was aimed to quantify the Gallic acid present in Lagerstroemia speciosa leaves (Lythraceae). The High-Performance Thin Layer Chromatography (HPTLC) quantification was performed for acetone (AE), methanolic (ME) and chloroform (CE) extract of leaves of L. speciosa. The pre-coated silica gel 60 F254 was used for complete separation of compounds using the mobile phase pet. Ether: ethyl acetate: formic acid (5:5:1v/v).The validation of the extracts was carried out using ICH guidelines for precision, repeatability and accuracy showing the Rf 0.49 against standard Gallic acid. Linearity range for Gallic acid was done from 200 to 1000ng/spot (AE) and200 ng to 600ng/spot (ME), with Correlation, coefficient r=0.99 (AE) and 0.54 (ME) in the said concentrations. The composition in crude leaf extract was determined to be of 49.712mg (AE) and 20.125mg (ME), while it was not found in chloroform extract against standard Gallic acid. Hence the proposed method was very simple, precise, accurate and easy for the screening of the bioactive compounds present in the acetone and methanolic extracts of the leaves of L. speciosa. It was observed that the acetone extract subjected to cytotoxicity showed promising activity at higher concentrations (100 and 200µg/ml) showed 92.9% and 87.13% inhibition against MCF-7 cell lines respectively. The photocatalytic activity of the acetone and methanolic extracts of methyl orange was found to be 90.25% (190min) and 89.03% (180min) respectively. Therefore this can be used as an indicator of purity of herbal drugs and formulation containing L. speciosa.

New simple and low-cost methods for periodic checks of Cyclone® Plus Storage Phosphor System.

The recent large use of the Cyclone® Plus Storage Phosphor System, especially in European countries, as imaging system for quantification of radiochemical purity of radiopharmaceuticals raised the problem of setting the periodic controls as required by European Legislation. We described simple, low-cost methods for Cyclone® Plus quality controls, which can be useful to evaluate the performance measurement of this imaging system.

Radiolabeling, quality control, and biological characterization of 177 Lu-labeled kanamycin.

Kanamycin is an antibiotic, isolated from Streptomyces kanamyceticus, which is used to treat serious bacterial infections. The fact that the present radioligand 99m Tc-kanamycin used for diagnosis is short-lived, raised a need to label and study kanamycin with one of the most important beta (ß) radiation emitting isotope 177 Lu. Labeling yield of 177 Lu-kanamycin was confirmed by different chromatography techniques such as paper chromatography, TLC, HPLC. Several experiments were performed to optimize labeling with changing reaction conditions such as pH, temperature, amount of ligand, and reaction time. In vitro stability analysis was performed incubation with human serum. Electrophoresis analysis was also conducted to determine the charge on 177 Lu-kanamycin. The biodistribution and scintigraphy were performed in normal mice and rabbit, respectively, at different time intervals of postinjection. 177 Lu-kanamycin was prepared with very high yield (~100%), with excellent stability in vivo and in vitro (>99% 6 hr postprep.), at pH 7. Maximum labeling was achieved at less reaction time (15 min), with maximum conjugation of the ligand (12.5 mg) with 177 Lu. Electrophoresis analysis showed net neutral charge. The radioligand showed rapid clearance from body in biodistribution and scintigraphy studies. The preparation 177 Lu-kanamycin could be used as a radio-pharmaceutical for infection imaging purpose, especially when transporting the radioligand to long-range distances.

A simple method for checking the proper functioning of a thin-layer radiochromatograph for radiochemical purity control of radiopharmaceuticals.

Thin-layer radiochromatography is used for carrying out radiochemical purity control of gamma-emitter radiopharmaceuticals by using thin-layer radiochromatography scanners. It has been developed and implemented a simple method for validating the proper functioning of these instruments. This method helps to ensure accurate results in the radiochemical purity controls of gamma-emitter radiopharmaceuticals.

HPTLC Method for Estimation of Topiramate in Solubility Studies, Diffusion Studies, Plasma, Brain Homogenate and Pharmaceutical Formulation.

Topiramate, 2,3:4,5-bis-O-(1-methylethylidene)-ß-d-fructopyranose, is an anticonvulsant drug indicated in the treatment and control of partial seizures and severe tonic-clonic (grand mal) seizures in adults and children. An economic and rapid high-performance thin-layer chromatographic (HPTLC) method was developed and was validated for the quantitative determination of topiramate in plasma, brain homogenate and pharmaceutical formulation. The simple extraction method was used for the isolation of topiramate from formulation, plasma and brain homogenate samples. HPTLC separation was achieved on an aluminum-backed layer of silica gel 60F254 plates using toluene : acetone (5.0 : 2.0, v/v) as mobile phase. Spots of developed plates were visualized by spraying of reagent [3.0% phenol in the mixture of ethanol : sulfuric acid (95 : 5, v/v)]. Quantitation was achieved by densitometric analysis at 340 nm over the concentration range of 1,000-5,000 ng/spot. The method was found to give compact spot for the drug (Rf: 0.61 ± 0.018). The regression analysis data for the calibration plots showed good relationship with a correlation coefficient of 0.9983. The minimum detectable amount was found to be 165 ng/spot, whereas the limit of quantitation was found to be 500 ng/spot. Statistical analysis of the data showed that the method is precise, accurate, reproducible and selective for the analysis of topiramate. The developed method was successfully employed for the estimation of topiramate in samples of equilibrium solubility study, diffusion study, microemulsion formulation and suspension formulation (developed in-house), rat plasma and rat brain homogenate samples.

Determination and Pharmacokinetic Study of Pirfenidone in Rat Serum by High-Performance Thin-Layer Chromatography.

A rapid, sensitive and selective high-performance thin-layer chromatography (HPTLC) method was developed and validated for the determination and pharmacokinetics of pirfenidone in rat serum. One-step protein precipitation by methanol is reported, and serum samples were separated by HPTLC using a simple mobile phase of toluene-methanol in the ratio of 8:2. The retardation factor of pirfenidone in the serum sample was 0.45 with the detection performed at 315 nm. The calibration curve was linear over the range of 100-1,200 ng/spot with a lower limit of quantitation of 40 ng/spot. The mean recovery of pirfenidone in serum was in the range of 70.6-75.8%, and intra-day and inter-day precision were both <14.1%. This method was successfully applied to the pharmacokinetic study of pirfenidone in rats on oral administration of the drug at a dose of 15.0 mg/kg.

Simultaneous Determination of Aspirin, Dipyridamole and Two of Their Related Impurities in Capsules by Validated TLC-Densitometric and HPLC Methods.

Aspirin (ASP) and dipyridamole (DIP) are widely used as a combination in pharmaceutical formulations for treatment of strokes. Many of these formulations are containing tartaric acid as an excipient (in DIP pellets formulation for sustained release), which increases the probability of formation of dipyridamole tartaric acid ester impurity (DIP-I). On the other hand, salicylic acid (SAL) is considered to be one of the synthesis impurities and a degradation product of ASP. In this work, two chromatographic methods, namely, TLC-densitometry and HPLC, have been established and validated for simultaneous determination of ASP, DIP, SAL and DIP-I. Good separation was achieved by using silica gel as stationary phase and toluene-methanol-ethyl acetate (2:3:5, by volume) as mobile phase in the case of TLC-densitometry and Zorbax ODS column with mobile phase consisting of phosphate buffer (pH 3.3)-acetonitrile-triethylamine (40:60:0.03, by volume) for HPLC. Influence of different organic solvents in mobile phase composition has been studied to optimize the separation efficiency in TLC densitometry. Moreover, factors affecting the efficiency of HPLC, like pH of the buffer used, organic solvent ratio in the mobile phase and flow rate, have been carefully studied using one variable at a time approach. Finally, the proposed methods were validated as per ICH guidelines.

Development and Validation of Stability-Indicating HPTLC Method for Estimation of Naratriptan Hydrochloride in Its Pharmaceutical Dosage Form and Its Content Uniformity Testing.

The present research project involves development and validation of a stability-indicating HPTLC method for the estimation of naratriptan-HCl in their pharmaceutical dosage forms and its content uniformity testing. Naratriptan-HCl was subjected to alkaline, acidic, oxidative, neutral, thermal (dry heat) and photo-degradation conditions. The chromatographic separation was carried out using a precoated silica gel G 60 F254 TLC plate as the stationary phase and dichloromethane-toluene-methanol-triethylamine (4 : 4 : 2 : 1, v/v/v/v) as the mobile phase. The spots of NRT-HCl and its degradation products were detected at 290 nm. The Rf value of NRT-HCl was found to be 0.60 ± 0.02. The linearity was obtained in the range of 100-500 ng/spot. The limit of detection and limit of quantitation were found to be 6.07 ng/spot and 18.41 ng/spot, respectively. The percentage recovery was found in the range of 98.87-99.55%. NRT-HCl was degraded under acidic, alkaline and oxidative conditions while stable under photolytic, neutral and dry heat conditions. The developed method was applied for estimation of naratriptan-HCl in marketed formulations and its content uniformity testing.

HPTLC and Spectrophotometric Estimation of Febuxostat and Diclofenac Potassium in Their Combined Tablets.

An accurate, precise, rapid, specific and economic high-performance thin-layer chromatographic (HPTLC) method has been developed for the simultaneous quantitative determination of febuxostat (FEB) and diclofenac potassium (DIC). The chromatographic separation was performed on precoated silica gel 60 GF254 plates with chloroform-methanol 7:3 (v/v) as the mobile phase. The developed plates were scanned and quantified at 289 nm. Experimental conditions including band size, mobile phase composition and chamber-saturation time were critically studied, and the optimum conditions were selected. A satisfactory resolution (Rs = 2.67) with RF 0.48 and 0.69 and high sensitivity with limits of detection of 4 and 7 ng/band for FEB and DIC, respectively, were obtained. In addition, derivative ratio and ratio difference spectrophotometric methods were established for the analysis of such a mixture. All methods were validated as per the ICH guidelines. In the HPTLC method, the calibration plots were linear between 0.01-0.55 and 0.02-0.60 µg/band, for FEB and DIC, respectively. For the spectrophotometric methods, the calibration graphs were linear between 2-14 and 4-18 µg/mL for FEB and DIC, respectively. The simplicity and specificity of the proposed methods suggest their application in quality control analysis of FEB and DIC in their raw materials and tablets. A comparison of the proposed methods with the existing methods is presented.

Analysis of 25 C NBOMe in Seized Blotters by HPTLC and GC-MS.

Use of unauthorized synthetic drugs is a serious, forensic, regulatory and public health issue. In this scenario, consumption of drug-impregnated blotters is very frequent. For decades, blotters have been generally impregnated with the potent hallucinogen known as lysergic acid diethylamide (LSD); however, since 2013 blotter stamps with N-2 methoxybenzyl-substituted phenylethylamine hallucinogen designated as "NBOMes" have been seized in Chile. To address this issue with readily accessible laboratory equipment, we have developed and validated a new HPTLC method for the identification and quantitation of 25-C-NBOMe in seized blotters and its confirmation by GC-MS. The proposed method was validated according to SWGTOX recommendations and is suitable for routine analysis of seized blotters containing 25-C-NBOMe. With the validated method, we analyzed 15 real samples, in all cases finding 25-C-NBOMe in a wide dosage range (701.0-1943.5 µg per blotter). In this situation, we can assume that NBOMes are replacing LSD as the main hallucinogenic drug consumed in blotters in Chile.

TLC Profiles of Selected Cirsium Species with Chemometrics in Construction of Their Fingerprints.

The dried aerial parts of 12 plants of Cirsium species were extracted with the Soxhlet apparatus using dichloromethane and methanol as solvents. Next, the extracts were separated by TLC methods to obtain the fingerprint chromatograms. The analysis was performed on silica gel or RP-18 layers as stationary phases using the following eluents: ethyl acetate/formic acid/acetic acid/water (12/1.5/1.5/4; v/v) for silica gel, and 5% (v/v) aqueous solution of formic acid/methanol (70/30; v/v) for the first development and the same system in the proportion of 50/50 (v/v) for the second development for RP-18. The double development was applied in the case of RP-18 plates. The analysis was performed for all Cirsium methanolic extracts and five selected standards (naringin, apigenin, rutin, caffeic acid and chlorogenic acid). The results were analyzed using chemometrics. The comparison of individual Cirsium species and the identification of unknown species were performed using the similarity indices (Pearson's correlation coefficient, determination coefficient and congruence coefficient), distance indices (Euclidean distance, Manhattan distance and Chebyshev's distance) and Multi-Scale Structural SIMilarity. Based on chemometric analysis, the first extract of the widely grown species is identified as Cirsium arvense and the second one as Cirsium rivulare.

TLC Fingerprinting and Pattern Recognition Methods in the Assessment of Authenticity of Poplar-Type Propolis.

Propolis is a "natural" remedy with prominent biological activity, which is used as dietary supplement. In the absence of clinical studies that would substantiate these claims, information on the biological activity of propolis is valuable. This study comprises chromatographic, image processing and chemometric approach for phenolic profiling of Serbian, Croatian and Slovenian propolis test solutions. Modern thin-layer chromatography equipment in combination with software for image processing was applied for fingerprinting and data acquisition, whereas the principal component analysis was used as pattern recognition method. Characterization of phenolic profile was performed along with the determination of the botanical and geographical origin of propolis. High-performance thin-layer chromatograms reveal that Central and Southeastern European propolis samples are rich in flavonoids. In addition, phenolic compounds proved to be suitable markers for the determination of European propolis authenticity.

Review of Properties and Analytical Methods for the Determination of Norfloxacin.

The first-generation quinolones have their greatest potency against Gram-negative bacteria, but newly developed molecules have exhibited increased potency against Gram-positive bacteria, and existing agents are available with additional activity against anaerobic microorganisms. Norfloxacin is a broad-spectrum antimicrobial fluoroquinolone used against Gram-positive and Gram-negative organisms (aerobic organisms). There are different analytical methods available to determine norfloxacin applied in quality control of this medicine in order to ensure its effectiveness and safety. The authors present an overview of the fourth generation of quinolones, followed by the properties, applications, and analytical methods of norfloxacin. These results show several existing analytical techniques that are flexible and broad-based methods of analysis in different matrices. This article focuses on bionalytical and pharmaceutical quality-control applications, such as thin-layer chromatography, microbiological assay, spectrophotometry, capillary electrophoresis (CE), and high-performance liquid chromatography (HPLC).

Validated RP-HPLC and TLC-Densitometric Methods for Analysis of Ternary Mixture of Cetylpyridinium Chloride, Chlorocresol and Lidocaine in Oral Antiseptic Formulation.

This work was concerned with development, optimization, application and validation of reversed phase high performance liquid chromatography (RP-HPLC) and thin layer chromatography (TLC)-densitometric methods for analysis of cetylpyridinium chloride, chlorocresol and lidocaine in Canyon(®) gel. The first developed RP-HPLC method depended on chromatographic separation on a ZORBAX Eclipse Plus C8 column, with elution with a mobile phase consisting of 0.05% phosphoric acid solution : acetonitrile : methanol (15 : 24 : 61, by volume), pumping the mobile phase at a flow rate of 1.00 mL min(-1), with ultraviolet detection at 220 nm. While in the subsequently developed method, the TLC-densitometric method, complete separation of the studied mixture was achieved using methanol : acetone : acetic acid (7 : 3 : 0.2, by volume) as a mobile phase, aluminum plates precoated with silica gel 60 F254 as a stationary phase and 215 nm as the scanning wavelength. Factors affecting the developed methods were studied and optimized; moreover, methods had been validated as per the International Conference of Harmonization guideline and the results indicated that the suggested methods were reproducible, reliable and applicable for rapid routine analysis. Statistical comparison of the two developed methods with the reported HPLC ones using F- and Student's t tests showed no significant difference.

Isolation, cytotoxic evaluation, and simultaneous quantification of eight bioactive secondary metabolites from Cicer microphyllum by high-performance thin-layer chromatography.

Chemical investigation of Cicer microphyllum resulted in the isolation and characterization of eight natural products viz. Stigmasterol, Oleanolic acid-3-acetate, Oleanolic acid, Biochanin A, Genistein, Pratensein, Chrysoeriol, and Luteolin. Herein, we report a novel, accurate, and cost-effective high-performance thin-layer chromatography method for the simultaneous quantification of the isolated natural products on silica-gel 60F254 plates using the solvent system n-hexane/ethyl acetate/formic acid (9.0:6.5:0.8, v/v/v). Natural products were quantified after postchromatographic derivatization with ceric ammonium sulfate. The method was validated as per the International Conference on Harmonization guidelines. All calibration curves showed a good linear relationship (r > 0.9943) within the test range. Precision was assessed by intra- and interday tests with relative standard deviations <1.82%, accuracy validation recovery 98.38-99.57% with relative standard deviations <1.00%. On quantification, Pratensein was a major constituent (0.921%). The screening for cytotoxic activity using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay resulted into identification of Luteolin as potent molecule with IC50 3.5 and 25.6 µg/mL against murine melanoma and human epidermoid carcinoma cell lines, respectively.

A Comprehensive Method for Quality Evaluation of Houttuyniae Herba by a Single Standard to Determine Multi-components, Fingerprint and HPTLC Method.

A method of quality evaluation by a single standard to determine multi-components (SSDMC), fingerprint and high-performance thin layer-chromatography (HPTLC) was developed for traditional Chinese medicine (TCM), and validated with dry Houttuyniae Herba (HH). In quantitative analysis, an SSDMC method involving nine components has been established with the desirable linearity (r(2) ≥ 0.9998), precision (RSD < 2.7%), accuracy (97.4 - 103.1%) and ruggedness. Compared with the results obtained using the external standard method (ESM), this alternative SSDMC method was found to have no statistically significant differences. In fingerprint analysis, nine of fourteen peaks were identified. Simultaneously, 15 HH samples from different origins were classified by similarity analysis and hierarchical clustering analysis (HCA). Additionally, the HPTLC method with three flavonoid markers was firstly established. The combination of SSDMC with the fingerprint and HPTLC method has been verified in the quality control of HH both quantitatively and qualitatively, and will provide a new quality evaluation pattern for TCMs.