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EN
Transfer of seven thin-layer chromatography (TLC) Global Pharma Health Fund E.V. Minilab protocols for screening counterfeit pharmaceutical products in the field to quantitative high-performance TLC (HPTLC)–densitometry methods was performed using a model process published previously. The developed and validated methods for tablets containing amlodipine besylate, cefpodoxime proxetil, cetirizine 2HCl, diclofenac sodium, efavirenz, mefenamic acid, and atovaquone + proguanil HCl involved the use of only relatively inexpensive and nontoxic solvents, Merck KGaA Premium Purity HPTLC silica gel 60 F254 plates, semi-automated sample and standard solution application with a CAMAG Linomat 4, and automated densitometry with a CAMAG Scanner 3 for detection, identification, and quantification. In addition, previously transferred HPTLC–densitometry methods for azithromycin and for cephalexin were used to analyze a new product of each drug to demonstrate the applicability of the methods.
EN
A model process, previously developed in a series of studies, allows for the transfer of thin-layer chromatography (TLC) methods for qualitative screening of counterfeit drug products published in the Global Pharma Health Fund (GPHF) Minilab manual and US Food and Drug Administration (FDA) Compendium of Unofficial Methods for Screening of Pharmaceuticals by TLC to quantitative high-performance TLC (HPTLC)–densitometry methods. This article describes HPTLC–densitometry methods developed and validated according to this model process for pharmaceutical products of amiodarone HCl, carvedilol, doxylamine succinate, magnesium salicylate, metoprolol succinate, nebivolol HCl, and salicylamide, for which qualitative screening methods have not been published in the Minilab manual or FDA Compendium. These methods use relatively inexpensive and nontoxic “green solvents” for sample and standard solution and mobile phase preparation, Merck Premium Purity silica gel 60 F254 plates, automated standard and sample solution bandwise application, and automated densitometry for the assessment of peak purity and identity and quantification. Corresponding to the quantitative HPTLC–densitometry methods, qualitative TLC screening methods for these drug products were developed and posted online with open access as supplements to the FDA Compendium.
EN
We present a new simple thin-layer chromatographic method designed for determination of the main alkaloids of Chelidonium majus L. In this study, we used roots and herb of the plant collected in spring and autumn. The alkaloid fractions were prepared according to modified pharmacopeial procedure [1]. In our method, we performed two-step elution onto silica gel plates. The first eluent consisted of chloroform, methanol, and water mixed with 70:30:4 proportion. The second eluent comprised of toluene, ethyl acetate, and methanol with 83:15:2 proportion. The described thin-layer chromatography (TLC) system allows qualitative and quantitative determination of the following alkaloids: sanguinarine, chelerythrine, chelidonine, coptisine, and berberine. For determination of protopine, eluent with n-buthanol, acetic acid, and water in 15:1.5:4 proportion was investigated.The dominant alkaloids observed in studied fractions were coptisine (1027.096 ± 13.367–287.474 ± 3.069 mg/100 g dry matter ± sdv) and chelidonine (1780.667 ± 263.522– 115.929 ± 14.694 mg/100 g dry matter ± sdv). The alkaloid detected in the least amount was chelerythrine (30.74 ± 7.526–1.143 ± 0.0651 mg/100 g dry matter ± sdv). The highest total amount of all alkaloids was determined in the fractions obtained from herbs in spring, and the lowest amount was detected in herbs autumn.Additionally, we compared amounts of studied alkaloids in different parts of plants (aerial parts and roots). The plants were collected in spring and autumn. Authors concluded that the presented method can be used as a valuable tool for screening studies on C. majus L.
EN
Rhizome extracts of Hedychium coronarium are widely used as phytotherapeutics. As of date, there is no documented study on the standardization of H. coronarium extract, and the following research is an effort in this direction. Coronarin D is an important bioactive compound present in H. coronarium which shows chemopreventive activity against cancer. H. coronarium extracts were assessed for coronarin D content for the first time. The extraction was checked using different solvents: n-hexane, acetone, and methanol. Coronarin D was separated on silica gel 60F254 high-performance thin-layer chromatography (HPTLC) plates by isocratic gradient method using n-hexane-ethyl acetate (80:20 v/v) as mobile phase. Densitometric quantification was performed at 231 nm in absorption mode. This method gave a well-defined peak at Rf 0.20 corresponding to coronarin D. The method was validated using International Conference on Harmonization (ICH) guidelines in terms of precision, repeatability, and accuracy. Linearity range of coronarin D was 200–1000 ng spot−1 with a correlation coefficient of R2 ± SD = 0.9987 ± 2.62% in the concentration range of 200–1000 ng spot−1. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 35 and 115 ng, respectively. Accuracy of the method was checked by recovery studies conducted at three different concentration levels, and the average percentage recovery was found to be 98.22 % for coronarin D. Among the different solvents, acetone produced maximum extraction efficiency of coronarin D. The proposed HPTLC method can be applied for robust identification and quantitative determination of coronarin D in H. coronarium extracts.
PL
Wykonano badania mineralogiczne, chemiczne i densytometryczne głów kości udowych oraz pokrywającej je chrząstki chorym z jałową martwicą, usuniętych w czasie wykonywania totalnej aloplastyki stawu biodrowego. Badania densytometryczne głów kości udowych wykonywane były chorym przed leczeniem operacyjnym, po ich usunięciu, oraz plastrom z tych głów o grubości 1,0 do 1,5 cm. Badaniom poddano głowy kości udowych 9 pacjentów w wieku 30-68 lat. Oprócz badań densytometrycznych wykonano badania przy pomocy mikroskopu cyfrowego, polaryzacyjnego i skaningowego, oraz przeprowadzono analizy chemiczne zarówno kości, jak i chrząstki stosując analizator do oznaczeń prowadzonych metodą EDS ( Electron Dispersive Spectroscopy). Wykonano także dyfraktometryczne analizy rentgenowskie chrząstek stawowych pobranych z tych głów. Badania wykazały, że w usuniętych głowach kości udowej występuje rozrzedzenie struktury kości gąbczastej zlokalizowane na szczycie głów i ich częściach bocznych . W chrząstce pokrywającej głowy występuje mineralizacja fosforanowa. Ma ona dwie postacie. przejawia się wyraźnym podwyższeniem zawartości Ca i P w chrząstce oraz, rzadziej obecnością mikro ziaren fosforanowych.
EN
Mineralogical, chemical and densitometry tests were conducted on femoral heads and cartilage acquired during total hip replacement in patients with avascular necrosis. Femoral heads densitometry was performed before and after the surgery, as well as on 1- to 1.5-centimeter slices of the femoral heads. Femoral heads from 9 patients between 30 and 68 years old were tested. In addition to densitometry, the sam les were analyzed using digital, polarizing and scanning microsco es, and chemical analysis of bone and cartilage was conducted using EDS (Electron Dispersive Spectrosco y). X-ray diffractometry of the joint cartilage acquired from the femoral heads was also performed. The tests have shown lower density of the s ongy bone on to and sides of the removed femoral heads. Femoral head cartilage shows phosphate mineralization. There are two forms of said mineralization: a distinct increase in Ca and P content in cartilage and, less frequently, presence of phos hate micrograins.
EN
High-performance thin-layer chromatography (HPTLC) method for the quantification of eugenol from nanostructured drug delivery systems was successfully developed and validated. The mobile phase consisted of n-hexane:acetone (7:3, v/v), and the densitometric scanning was performed in the absorbance mode at 280 nm. The method was valid with respect to linearity and range, accuracy, precision, specificity, detection limit (DL), and quantitation limit (QL). The linearity of the method was established by a correlation coefficient value of 0.9930 ± 0.0013. The precision was tested by checking intra-day (repeatability) and inter-day (intermediate precision) variations. The method was established to be precise by low relative standard deviation (RSD) values for different concentration of eugenol. The results of the recovery studies of eugenol from preanalyzed samples demonstrated the accuracy of the method. The specificity of the developed method for the analysis of eugenol in the nanoemulsion gel and nanoparticles samples was confirmed by comparing the spectra obtained in standard and sample analysis. The DL and QL were determined to be 31.41 and 95.17 ng band−1, respectively, for the HPTLC method. The forced degradation studies revealed on eugenol established the effectiveness of the developed and validated method. The developed and validated HPTLC method was found to be a stability-indicating one, as indicated by the results of forced degradation studies, for its use during the accelerated stability studies of the nanoemulsion gels and nanoparticles of eugenol.
EN
Transfer of two rapid thin-layer chromatography (TLC) screening methods used to detect markedly substandard and fake pharmaceutical products to quantitative high-performance TLC (HPTLC)-densitometry methods is demonstrated using a model procedure that was published earlier. These TLC methods for diazepam and amodiaquine are contained in a Compendium of methods by Kenyon and Layloff and a Minilab method manual from Global Pharma Health Fund E.V., respectively, for use in countries with limited resources. Merck HPTLC Premium Purity silica gel 60 F254 glass plates, automated standard and sample solution application with a CAMAG Linomat 4, and automated densitometry with a CAMAG Scanner 3 were used for detection, identification, and quantification. Sample peak identity and purity validation were carried out by spectral comparison checks available in the winCATS software. Accuracy was estimated by the standard addition approach with overspotting standard and sample solutions. HPTLC gives better efficiency, selectivity, and resolution than TLC, and the new methods overcome the deficiencies in technology related to manual application and visual zone comparison that do not allow the Compendium and Minilab TLC procedures to support regulatory compliance actions. These new methods can be fully validated according to the International Conference on Harmonization guidelines or by interlaboratory studies if required by their applications.
EN
The purpose of this work was to develop a TLC-densitometric method for simultaneous identification and quantitative determination of azithromycin, clarithromycin, roxithromycin, spiramycin, and troleandomycin. The method was developed on TLC aluminium plates precoated with silica gel F254 using solvent system izopropanol:n-hexane:ammonia 25% (8:12:3, v/v/v), which gives compact spots for azithromycin (RF = 0.65), clarithromycin (RF = 0.54), roxithromycin (RF = 0.49), spiramycin (RF = 0.22), and troleandomycin (RF = 0.36). Densitometric analysis was carried out at 478 nm after spraying with (1:4, v/v) sulphuric acid:ethanol and heating at 100°C for 5 min. The linear regression analysis data for the calibration plots showed good linear relationship with correlation coefficient higher than 0.99. The method is distinguished by high sensitivity, with limit of detection (LOD) from 0.34 μg/spot for troleandomycin to 0.67 μg/spot for clarithromycin and limit of quantification (LOQ) from 1.02 μg/spot for troleandomycin to 2.04 μg/spot for clarithromycin and a wide linearity range from 2 to 12 μg/spot for spiramycin and 2–15 μg/spot for other antibiotics. The precision of the determination was good; relative standard deviation (RSD) varied in the range from 1.49% to 4.14%.
EN
A simple, selective, precise, and stability-indicating thin-layer chromatographic method has been developed and validated for analysis of some angiotensin II receptor antagonists (AIIRAs), namely, Losartan potassium (Los-K), Irbesartan (Irb), and Candesartan cilexetil (Cand) in the bulk drug and in pharmaceutical formulations (tablets). The method was based on using TLC plates pre-coated with silica gel G 60 on aluminum sheets as stationary phase and the development system was performed using chloroform:methanol (9:1) giving well separated and compact spots for all the studied drugs (RF values 0.41–0.53). The separated spots were characterized by viewing under the UV lamp, then visualized as orange spots by spraying with Dragendorff’s reagent and measured by densitometry. Under the optimum chromatographic conditions, linear relationships were obtained between response and concentrations of each studied drug with high correlation coefficients (0.9985–0.9994). Good accuracy and precision were successfully obtained for the analysis of tablets containing each drug alone or combined with diuretic drug hydrochlorothiazide (HCTZ). No interferences could be observed from the co-formulated HCTZ, commonly encountered excipients present in tablets as well as the degradation products. The results were compared successfully with reported methods and can be used as a stability-indicating assay.
EN
Comparison of classical densitometry, video-scanning, and capillary electrophoresis was performed for determination of angiotensin II receptor antagonist, valsartan, and calcium channels blocker, amlodipine, in a combined dosage form. Thin layer chromatography was performed on RP8F254 TLC plates with a mobile phase consisting of acetonitrile-phosphate buffer at pH 9.0 (5:5, v/v) and temperature 20 °C. Densitometry was done in the reflectance mode at 217 nm for valsartan and in the absorbance mode at 370 nm for amlodipine. Video-scanning was elaborated at 254 and 366 nm for valsartan and amlodipine, respectively. For chromatographic analysis, calibration plots were constructed in the range of 0.4–2.8 μg per spot for valsartan and 0.02–0.14 μg per spot for amlodipine. Capillary electrophoresis (CE) was performed using a 75 μm × 94 cm fused silica capillary (72 cm effective length), 0.01 mol L-1 borate buffer at pH 8.0, 20 kV voltage, 30 °C temperature, hydrodynamic injection (10 mbar, 6 s) and UV detection at 237 nm. Calibration plots were constructed in the range of 0.1–0.6 mg mL-1 for valsartan and 0.005–0.03 mg mL-1 for amlodipine. All methods were validated in respect to robustness, specificity, stability, linearity, precision, and accuracy. Generally, statistical comparison between the methods did not show significant differences so all procedures are suitable for pharmaceutical analysis.
EN
Studies on the evaluation of separation efficacies are of primary interest to forensic analysts for newly available pesticides. In the present work, a method is described for the separation evaluation of three selected organophosphorus fungicides (OPFs) ditalimfos (D), edifenfos (E), and tolclofos-methyl (TM) by reversed-phase high-performance thin-layer chromatography (RP-HPTLC). The method is based on the separation of three OPFs on silica gel 60 RP-18WF254 plates with varying mobile phase compositions (10:0–6:4) of methanol-water. The relationship between the mobile phase composition and retention parameters (RF and RM) as well as separation parameters (ΔRF, RS, α, RFα) was analyzed. The three OPFs are completely separated from each other with ΔRF ≥ 0.04, except for the pair of compounds E-TM in the mobile phase composition 10:0, 7:3, 6.5:3.5, and 6:4. Under the chromatographic conditions used, TM was adsorbed the strongest, followed by E and D, which is indicated by the higher RM values obtained for TM. Peak resolution (RS) values greater than 1.5 were obtained over the entire range of mobile phase composition, except for the pair of compounds E-TM. The UV apex of maximum absorption was 200 nm for all the three OPFs as measured by multiwave-length scan in the UV range, and higher values of peak area and peak height were obtained at the same wavelength. The present study clearly indicates that the system of RPHPTLC with mobile phase methanol-water in a volume composition 8:2 (υ/υ) provides the optimum conditions for the separation of the three OPFs. However, the complete separation of E from TM was not achieved using this system.
EN
Transfer of four rapid thin-layer chromatography (TLC) screening methods used to detect substandard and counterfeit pharmaceutical products to quantitative high-performance TLC (HPTLC)-densitometry methods is demonstrated. These methods for acetaminophen, acetylsalicylic acid, ibuprofen, and chlorpheniramine maleate are contained in a Compendium of methods developed by Kenyon and Layloff for use in countries with limited resources. The new quantitative methods use Merck HPTLC silica gel 60 F254 glass plates, automated standard and sample application, and automated densitometry for detection, identification, and quantification. Standard and sample solution preparation and application procedures for obtaining calibration curves and bracketed samples are described. The HPTLC plates give better efficiency, selectivity, and resolution than TLC, and the new methods overcome the deficiencies in technology related to manual application and visual zone comparison that do not allow the Compendium TLC procedures to support regulatory compliance actions. These transferred methods can be fully validated according to International Conference on Harmonization (ICH) guidelines or by interlaboratory studies if their applications require. The approach described can be used to transfer the remaining Compendium methods as well as the GPHF [Global (formerly German) Pharma Health Fund E.V.] Minilab kit TLC screening methods.
EN
Planar chromatography (TLC) is known as an effective tool for separation of complex biosamples highly loaded with interfering substances. The main goal of this research communication is to demonstrate a capability of micro-TLC methodology followed by simple one-step liquid extraction as fast fractionation tool for wide range of non-polar, low-molecular mass substances extracted from birds’ feathers samples. The main analytical problem concerning birds’ feathers is the presence of interfering matrix, mainly composed of waxes-like impurities. Such substances can be strongly adsorbed on the stationary phase. Proposed simple extraction protocol and fast micro-TLC separation procedure is based on dichloromethane: methanol mixtures. We used this methodology for fractionation of non-polar compounds present in feathers of buzzard, cormorant and little owl. Described methodology can be applied for fast fractionation or screening of whole range of target substances as well as chemo-taxonomic studies and fingerprinting of complex mixtures, which are present in raw biological samples. Particularly, the micro-TLC separation combined with PMA staining and UV light detection seems to be an effective tool for fast and low-cost characterization of non-polar compounds from birds’ feathers or uropygial gland secretion products.
PL
Pióra, ze względu na powszechną obecność ptaków w różnych typach środowisk, mogą znależć zastosowane jako materiał do badań biomonitoringowych. Wymaga to opracowania ekstrakcji niepolarnych związków zawartych w upierzeniu oraz metody ich skutecznego rozdzielania z wykorzystaniem technik chromatograficznych. Zasadniczym problemem analitycznym jest obecność w piórach substancji o charakterze wosków, które bardzo silnie oddziaływują z chromatograficzną fazą stacjonarną na bazie krzemionki lub oktadecylsilanu. Adsorbenty te powszechnie stosowane jako fazy stacjonarne w technikach cienkowarstwowych kolumnowych. Głównym problemem jest to, iż naniesienie na kolumnę chromatograficzną nieodpowiednio oczyszczonych ekstraktów próbek biologicznych zawierających woski jako zanieczyszczenia, zazwyczaj prowadzi do jej zniszczenia. Zaletą chromatografii planarnej jest w tym przypadku to, że dana płytka jest wykorzystywana do rozdzielania tylko raz. Celem niniejszej pracy było opracowanie szybkiej procedury analitycznej z wykorzystaniem prostej jednoetapowej ekstrakcji cieczą oraz rozdzielania uzyskanych ekstraktów substancji niepolarnych obecnych na powierzchni piór ptaków, za pomocą mikropłytek chromatograficznych. Uzyskane wyniki wskazują na przydatność metodologii ekstrakcji cieczą oraz detekcji fluorescencyjnej w badaniach chemotaksonomicznych oraz biomonitoringu.
EN
The chromatographic-densitometric method was developed for the simultaneous determination of various pharmaceutical agents, such as haloperidol, fluxetine, promazine, doxepin, clonazepam, alprazolam, and risperidone in biological material. Two mobile phases, A (acetone-diethylamine-cyclohexane (2.5:2.5:20, υ/υ/υ)) and B (trichloromethane-acetone-25% NH3 (25:25:0.5, υ/υ/υ)), were used for the separation of the above-mentioned compounds. Silica gel-covered F254 TLC plates were used as stationary phases. Densitometric recording was carried out at 254 nm wavelength. Well-developed peaks, easy to quantify, and quality analysis were obtained after achieving the separation of compounds in the developed conditions. It was demonstrated that the presence of a matrix (plasma or urine) did not affect the shape of the peaks and their localization on the chromatograms.
EN
Seven different thin-layer chromatography stationary phases, one additional stationary layer pretreatment, eight mobile phases, two spotting techniques, and three detection reagents were evaluated for the determination of glucose in mouse fecal samples. Quantitative analysis was performed by slit-scanning densitometry. The optimal system was found to be Merck silica gel HPTLC plates with a concentrating zone developed with 1-butanol-glacial acetic acid-diethyl ether-deionized water 27:18:5:3. α-Naphthol-sulphuric acid detection reagent was found to give the best quantitative results, while the naphthoresorcinol reagent was the most useful for qualitative analysis. Semiautomatic application of samples with a CAMAG Linomat was found to give more compact bands and better separations than manual application. Using this system, quantification of glucose was achieved in mouse fecal samples. The amounts of glucose in the fecal samples of BALB/c mice infected with the intestinal trematode E. caproni were compared to control samples of uninfected mice. On the third and tenth days of postinfection, it was determined that the amount of glucose in the infected fecal samples was significantly greater than in the control samples. This indicates that metabolic profiling of glucose using TLC is possible in the mouse model and that TLC may potentially be used to test for the presence of E. caproni in humans.
EN
A simple and fast high-performance thin-layer chromatographic method has been developed for the simultaneous determination of ampicillin and amoxicillin. Titanium(IV) silicate (a synthetic inorganic ion-exchanger)-coated thin-layer chromatography (TLC) plates were used to separate them, employing a mixture of K2HPO4 (0.1 M) + KH2PO4 (0.1 M), 1:1 (υ/υ), as mobile phase. The development time was 18 min. The plates were sprayed with fresh 1% solution of ninhydrin in ethanol. The developed method enables highly contrasted chromatograms with red purple spots in white background. Densitometric measurements were made at wavelength 546 nm using Camag TLC Scanner-3. The ampicillin and amoxicillin recovery of the total procedure were equal to 99.99 and 100.43, respectively. The procedure is quantitatively characterized. Linearities were r2 > 0.9958 and 0.9954 for ampicillin and amoxicillin, respectively, and the relative standard deviations were <0.89 and 0.61, respectively. The limits of detection were 2.9 and 1.5 ng per spot and the limits of quantification were 14.5 and 7.5 ng per spot, respectively. The method is rapid, selective, precise, and accurate and thus can be used for the routine analysis of pharmaceutical preparations in quality control laboratories of the pharmaceutical industry. The method is successfully applied for the determination of ampicillin and amoxicillin in human blood plasma and urine.
PL
Chromatografia cienkowarstwowa (TLC) jest prostą i wydajną metodą analityczną powszechnie wykorzystywaną do rozdzielania oraz oznaczeń ilościowych szerokiej gamy substancji, obecnych w złożonych próbkach biologicznych, środowiskowych oraz preparatach farmaceutycznych. Główną zaletą TLC jest możliwość prostej detekcji rozdzielonych substancji przy pomocy bezpośredniej obserwacji płytki w świetle widzialnym lub fluorescencji plamek, uwidaczniającej się przy naświetleniu płytki promieniowaniem elektromagnetycznym z zakresu UV. Efektywne rozdzielenie mieszanin wieloskładnikowych może być uzyskane przy użyciu płytek o wymiarze nie przekraczającym 5 cm wzdłuż drogi rozwijania fazy ruchomej. Dzięki temu uzyskuje się znaczące skrócenie czasu analizy oraz polepszenie warunków detekcji do badań ilościowych. Nasze badania wskazują, że na płytce HPTLC typu RP o wymiarach 5 x 5 cm możliwe jest rozdzielenie ponad 240 plamek chromatograficznych, w trybie rozdzielania dwukierunkowego. W szczególności podano szereg przykładów rozdzielania jedno oraz dwukierunkowego mieszanin wieloskładnikowych wzorców sterydów, fulerenów, preparatów farmaceutycznych oraz ekstraktów barwników spiruliny.
EN
Thin-layer chromatography (TLC) is still commonly used as a simple and efficient tool for separation and quantification of several analytes which are present in complex pharmaceutical, biological, and environmental samples. The main advantage of TLC is that the bands or spots detected can be easily inspected under visible and UV light conditions and then digitalized using simple office scanners. In analytical practice, modern high-performance-thin-layer chromatography (HPTLC) involving a reversed phase (RP) plate is particularly suitable for efficient separation and sensitive pharmaceutical formulations. It is noteworthy that when using HPTLC plates, the mobile phase developing distance can be reduced to less than 50 mm. This conclusion is based on the observation that the minimum values of the plate height (H) can be achieved if the solvent migration distance along the HPTLC plate ranges from 30 to 40 mm. Under such conditions the total analysis time can be dramatically reduced in comparison to chromatographic separations performed on typical 10 or 20 cm long TLC plates. In this work there is estimated the micro-TLC plate peak capacity using one and two dimentional development performed in a temperature controlled, micro-TLC chamber (Fig. 1). The peak capacity estimation was based on the recorded densitometric profiles of HPTLC plates obtained from real samples, separated under 1D and 2D conditions, including: testosterone and its derivatives mixture (Figs. 2 and 3), the Azucalen herbs extract (Fig. 4), water and organic liquids extracts of the Spirulina maxima dyes (Fig. 5) as well as of C60 and C70 fullerenes mixture (Fig. 6). The experimental data show that micro-TLC plate working under 2D development protocol is capable of separation of more than 240 spots. It is also proved that this method can be useful for fast fingerprinting of complex biological mixtures.
EN
The influence of TSH on bones is still vastly unknown and the information that is known is considered controversial. This important relationship has not been studied in detail. The aim of our research was to assess the correlation between TSH, thyroid hormone and bone mineral density in children measured by DXA scanning. Our study group included 36 children (16 girls and 20 boys) mean age 12.9 š 3.3 years. Basic anthropometrical measurements were performed (height, weight, body mass index-BMI), in all subjects. Blood was collected and measured for TSH and FT4. Bone mineral density of lumbar spine (L2-L4 BMD) and total body (Total Body BMD) were measured by DXA and expressed as bone mineral content (BMC [g]) and bone mineral density (BMD [g/cm2]). BMD Z-Score was also calculated. Correlation between the parameters obtained by DXA and anthropometrical data, TSH and thyroid hormone concentration were calculated. A statistically significant positive correlation was observed between height, weight and BMI and BMD which was calculated. Weight and BMI also had a statically significant correlation with Z-Score and total bone mineral content (BMC – expressed in grams). There was a statistically significant positive correlation between TSH level and Z-Score for both L2-L4 lumbar spine and for total body. TSH did not correlate significantly with BMD [g/cm2] and BMC [g]. FT4 was negatively and significantly correlated with Z-Score for both L2-L4 lumbar spine and for total body. There was also no significant correlation between FT4 and BMD [g/cm2] and BMC [g]. Conclusion: 1. Thyroid stimulating-hormone (TSH) appears to be associated with maintenance of bone mineral density in children. 2. BMD Z-Score especially from L2-L4 lumbar spine assessed by DXA scanning is correlated best with hormonal and biochemical factors potentially influencing bone mineralization in children.
EN
A simple, accurate, and rapid high-performance thin-layer chromatographic (HPTLC) method for quantification of the anticancer marker zerumbone in different parts of Zingiber zerumbet Smith has been established and validated. Chromatography was performed on aluminium foil-backed silica gel 60 F 254 HPTLC plates with the binary mobile phase ethyl acetate-hexane 1.5:8.5. Ultraviolet detection was performed densitometrically at the maximum absorbance wavelength, 250 nm. Regression analysis data for the calibration plot showed there was a linear relationship between response and concentration in the range 60–260 ng with a regression coefficient of 0.9997. The limits of detection and quantification were 20 and 60 ng, respectively. The instrumental precision and repeatability of the method were found to be 0.80 and 1.08%, respectively. Recovery ranging from 97.85 to 100.12% indicated the excellent accuracy of the method. The developed HPTLC method was successfully used for analysis of the marker in different parts of Z. zerumbet , and the maximum zerumbone content (1.81%) was found in the rhizome.
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EN
A simple and reliable TLC method for analysis of -lipoic acid (LA) with post-chromatographic derivatisation with palladium(II) chloride immersion reagent has been developed and evaluated. Separation of LA was performed on 20 cm × 10 cm RPTLC plates with 2-propanol-methanol-acetone-water-acetic acid 6:4:2:8:0.2 ( v/v ) as mobile phase. Yellow complexes formed in situ were scanned at 375 nm. The migration distance of LA was 43.0 mm. The relationship between peak area and amount of LA applied was evaluated by use of linear (1.0–3.0 µg per band) and second-degree polynomial (0.5–5.0 µg per band) regression functions. The correlation coefficient ( r = 0.999), the limit of quantification (0.39 µg per band), recovery (98.5–105.2%), and precision (1.8–2.9%) obtained by use of the procedure were satisfactory. The method was used for analysis of LA in several drug formulations and selected dietary supplement preparations. The LA content was 99.5–101.0% in the drug formulations, 98.8–99.5% in three of five dietary supplements tested, and 48.0–185.0% in two other dietary supplements.
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