Indoprofen类似物的合成和表征

以邻硝基苯甲醛为超始原料，合成2-溴甲基-3-喹啉酸乙酯中间体，其分别与 苯胺、2-氯代苯胺、3-氯代苯胺、2-甲基苯胺和3-甲基苯胺发生Williamson反应， Williamson反应产物经闭环反应，得到新化合物2，3-二氢-1-氧代-2-苯基-1H-吡 咯并[3，4-b]喹啉（4a），2，3-二氢-1-氧代-2-（2-氯代苯基）-1H-吡咯并[3， 4-b]喹啉（4b），2，3-二氢-1-氧代-2-（3-氯代苯基）-1H-吡咯并[3,4-b]喹啉（ 4c），2，3-二氢-1-氧代-2-（2-甲基苯基）-1H-吡咯并[3，4-b]喹啉（4d）和2， 3-二氢-1-氧代-2-（3-甲基苯基）-1H-吡咯并[3，4-b]喹啉（4e）。12个新化合物 由元素分析、红外光谱、核磁共振氢谱、质谱予以证实。     

Development and Validation of an Stability Indicating RP-LC Method for Determination of Imatinib Mesylate

A new, sensitive and stability indicating liquid chromatographic method has been developed for the determination of imatinib mesylate (IM). Efficient chromatographic separation was achieved using a C₁₈ column with simple mobile phase combination delivered in an isocratic mode and quantitation was carried out using ultraviolet detection. For the first time, a novel microwave assisted degradation procedure was employed for stress testing studies. In addition, orthogonal separation technique was applied to demonstrate selectivity of the proposed method. The method has demonstrated excellent linearity over the range of 25–1,600 ng mL^?1. Moreover, the method was found to be sensitive with a low limit of detection (3.35 ng mL^?1) and limit of quantitation (10.16 ng mL^?1). The method has shown good and consistent recoveries (99.35–100.69%) with low intra- and inter-day relative standard deviation (RSD) (<2.5%). Experimental design confirmed that peak area was unaffected by small changes in critical factors, in robustness study. The validated method was successfully applied for determination of IM in pharmaceutical formulations.     

Development and Validation of an Stability Indicating RP-LC Method for Determination of Imatinib Mesylate

A new, sensitive and stability indicating liquid chromatographic method has been developed for the determination of imatinib mesylate (IM). Efficient chromatographic separation was achieved using a C₁₈ column with simple mobile phase combination delivered in an isocratic mode and quantitation was carried out using ultraviolet detection. For the first time, a novel microwave assisted degradation procedure was employed for stress testing studies. In addition, orthogonal separation technique was applied to demonstrate selectivity of the proposed method. The method has demonstrated excellent linearity over the range of 25–1,600 ng mL⁻¹. Moreover, the method was found to be sensitive with a low limit of detection (3.35 ng mL⁻¹) and limit of quantitation (10.16 ng mL⁻¹). The method has shown good and consistent recoveries (99.35–100.69%) with low intra- and inter-day relative standard deviation (RSD) (<2.5%). Experimental design confirmed that peak area was unaffected by small changes in critical factors, in robustness study. The validated method was successfully applied for determination of IM in pharmaceutical formulations.

     

高效液相色谱法测定氟白普洛芬

氟白普洛芬(FB)为一具有光敏感特性的非类固醇抗发炎药物(NSAID s)。当将氟白普洛芬的甲醇溶液以低压汞灯照射,可观察到氟白普洛芬有3种光解产物的产生。建立了一种灵敏度高、准确的、稳定的高效液相色谱分析法(HPLC),并藉此观察氟白普洛芬的光解反应。日内、日间实验的相对标准偏差(RSD)值皆可低于1.1%和1.7%,回收率在98.2%~102.0%之间。结果显示,HPLC分析方法具有良好的选择性和专一性。氟白普洛芬的光解反应在不同醇性溶剂中并无显著的差异。     

Development and Validation of a Stability Indicating HPLC Method for Determination of Granisetron

The aim of this study was to study the stress degradation of granisetron and analysis of the drug in the presence of its degradation products. Forced degradation studies were conducted on bulk sample using acidic, alkaline, oxidative, heat and photolytic conditions. Granisetron was relatively unstable under acidic, alkaline and oxidative conditions. Separation of granisetron and degradation products was achieved using a Nova‐Pak C₈ column and acetonitrile‐KH₂PO₄ 25 mM (75:25, v/v) as mobile phase with UV detection at 305 nm. The method was linear over the range of 0.2‐15 μg/mL granisetron (r² > 0.999). The within‐day and between‐day precision values were also in the range of 0.5‐4%. The proposed method was successfully applied for quantitative determination of granisetron in tablets and in vitro dissolution studies.     

Development and Validation of an HPLC Method for Determination of Ceftiofur Sodium

An isocratic high-performance liquid chromatographic method has been developed for assay of ceftiofur sodium in drug substance and in sterile powder for injection. Chromatography was performed on a 250 mm × 4.6 mm, 5 μm particle, C₁₈ column with a 78:22 (v/v) mixture of 0.02 m disodium hydrogen phosphate buffer (pH adjusted to 6.0 with 85% orthophosphoric acid) and acetonitrile as mobile phase, at a flow rate of 1.0 mL min⁻¹. The separation was monitored by UV detection at 292 nm. Validation of the method for linearity and range, intra- and inter-day precision, accuracy, specificity, recovery, robustness, and limits of quantification and detection yielded good results. The calibration plot was linear from 20.0–120.0 μg mL⁻¹ and the correlation coefficient was 0.9999. It was shown that ceftiofur was degraded under acidic, alkaline, oxidative, and photolytic conditions. The method was found to be stability-indicating and could be used for routine analysis of ceftiofur sodium for injection.     

Development and Validation of a Stability Indicating LC Method for the Determination of Faropenem in Pharmaceutical Formulations

A simple, selective and sensitive stability indicating LC method has been developed and validated for the determination of faropenem in bulk drug and pharmaceutical formulations in the presence of degradation products. The separation was achieved by using an isocratic mobile phase mixture of acetate buffer of pH 3.5 and methanol (65:35, v/v) and 250 mm × 4.6 mm I.D., 5 μm particle size SGE make Wakosil C-18 AR column at flow rate of 1.0 mL min^?1 with detection at 305 nm. The retention time of faropenem is 6.63 min and was linear in the range of 5–75 μg mL^?1 (r = 0.9999). The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation and was found to be unstable in all the stress conditions. The proposed method was successfully employed for quantification of faropenem in bulk drug and its pharmaceutical formulations.     

Bioanalytical Method Development,Validation and Stability Assessment of Xanthohumol in Rat Plasma

Xanthohumol (XH) a prenylated chalcone has diverse therapeutic effects against various diseases. In the present study, a bioanalytical method was developed for XH in rat plasma using reverse phase high performance liquid chromatography. The validation of the method was performed as per ICH M10 guidelines using curcumin as an internal standard. The Isocratic elution method was used with a run time of 10 min, wherein the mobile phase ratio 0.1% v/v OPA (A): Methanol (B) was 15:85 v/v at flow rate 0.8 mL/min and injection volume of 20 µL. The chromatograms of XH and curcumin was recorded at a wavelength of 370 nm. The retention time for XH and curcumin was 7.4 and 5.8 min, respectively. The spiked XH from plasma was extracted by the protein precipitation method. The developed method was linear with R² value of 0.9996 over a concentration range of 50–250 ng/mL along with LLOQ. The results of all the validation parameters are found to be within the accepted limits with %RSD value less than 2 and the percentage recovery was found to be greater than 95%. Based on the %RSD and percentage recovery results it was confirmed that the method was precise and accurate among the study replicates. LOD and LOQ values in plasma samples were found to be 8.49 ng/mL and 25.73 ng/mL, respectively. The stability studies like freeze thaw, short term and long-term stability studies were also performed, %RSD and percentage recovery of the XH from plasma samples were within the acceptable limits. Therefore, the developed bioanalytical method can be used effectively for estimation of XH in plasma samples.     

Development,Validation, and Application of a Novel Method for Mammalian Sphingomyelin Synthase Activity Measurement

Sphingomyelin synthase (SMS) is a key enzyme for the synthesis of mammalian sphingomyelin. The use of SMS plays diverse roles in physiology and pathology; thus, it could be a useful disease marker and/or drug target. We report here a novel and sensitive method for SMS activity measurement. Using a HPLC column (C18-RP), SMS activity was monitored by measuring a decrease of the fluorescent substrate C6-4-nitrobenzo-2-oxa-1,3-diazole (NBD)-ceramide (C6-NBD-Cer) and increase of the product (C6-NBD-SM). Time- and protein-dependent formation of C6-NBD-SM was investigated and enzyme kinetics was determined [K _m  = 7.49 ± 0.48 µM (C6-NBD-Cer) and V _max  = 27.86 ± 0.73fmol/h/mg homogenate protein]. This method is feasible, rapid, accurate, highly reproducible, and suitable for quantifying SMS enzyme activity in SMS inhibitor screening studies. A known SMS inhibitor, D609, was employed to evaluate the assay and its IC₅₀ value has been determined.

[Supplementary materials are available for this article. Go to the publisher's online edition of Analytical Letters for the following free supplemental resources: Tables and figures]     

Development and Validation of a LC Method for the Determination of Pramipexole Using an Experimental Design

A rapid and sensitive RP-HPLC method with UV detection for routine control of pramipexole in tablets was developed. Chromatography was performed with mobile phase containing a mixture of acetonitrile/phosphate buffer (60/40; v/v) with a flow rate of 0.8 mL min⁻¹. Quantitation was accomplished with the internal standard method; the procedure was validated by linearity (correlation coefficient = 0.99892), accuracy, robustness and intermediate precision. Limit of quantitation and limit of detection were found to be 4.5 μg and 1.4 μg respectively, which indicates the method is highly sensitive. Experimental design was used during validation to calculate method robustness and intermediate precision, for robustness test three factors were considered; percentage v/v of acetonitrile, flow rate and pH; an increase in the flow rate results in a decrease of concentration found of the drug, while the percentage of organic modifier and temperature have no important effect on the response. For intermediate precision measure the considered variables were: analyst, equipment, days and obtained RSD value (0.56%, n=24) which indicated a good precision of the analytical method. The method was found to be applicable for determination of the drug in tablet formulations and the results of the developed method were compared with those of the UV spectrophotometric method to access the active pramipexole content. Revised: 13 March and 25 April 2006     

Development and Validation an LC Method for the Determination of Bendroflumethiazide in Human Plasma and its Pharmacokinetics

A simple, rapid, sensitive high performance liquid chromatography method with fluorescent detection was developed and validated for the determination of bendroflumethiazide in human plasma. Extraction from the plasma was by liquid-liquid extraction using ethyl acetate. Mosapride citrate was used as the internal standard. The chromatographic separation was performed on reverse phase LiChrosphere C18 column with mobile phase comprising of acetonitrile and phosphate buffer (38:62 v/v). The assay precision ranged from 0.9–12.5 and accuracy between 96.8–108.8%, revealing that the method has good reproducibility over the concentration range of 0.98–100.16 ng mL⁻¹. The validated method has been applied to analyze the bendroflumethiazide concentrations for application in pharmacokinetic, bioavailability or bioequivalence studies.     

A Stress Stability Behavior and Development of an LC Assay Method for Anastrozole

This present work narrates the stress stability behavior and development of a liquid chromatographic method for the quantitative determination of anastrozole. Anastrozole is appropriately used when using substantial amounts of aromatizing steroids, or when one is prone to gynecomastia and using moderate amounts of such steroids. A chromatographic separation was achieved on a Hichrom RPB18 (250 × 4.6 mm, 5 μ) column using water and mixture of acetonitrile and methanol (1:1 ratio) as mobile phase. Forced degradation studies were performed on bulk samples of anastrozole using acid, base, hydrogen peroxide, heat and UV light. Degradation of the drug substance was observed in base hydrolysis. Degradation product formed under base hydrolysis was found to be Imp-C. The sample solution and mobile phase were found to be stable up to 48 h. The developed method was validated with respect to linearity, accuracy, precision, robustness and forced degradation studies prove the stability indicating power of the method.     

Development and Validation of Stability Indicating RP-HPLC Method for the Determination of Process and Degradation-Related Impurities in Sugammadex Sodium Drug Substance

The aim of this study is to develop and validate a sensitive and specific stability-indicating reversed-phase high-performance liquid chromatographic (RP-HPLC) method for the quantitative determination of Sugammadex sodium together with its process and possible degradation impurities. The pKa value is 2.82. The chromatographic conditions have been optimized by the Hypersil Gold 250 mm X 4.6 mm, 3 µ RP-18 columns with gradient elution using a mobile phase composed of 0.1% phosphoric acid, acetonitrile, and methanol. The eluents were monitored at 205 nm with a flow rate of 1.0 mL/min with an injection volume of 20 µL. The optimized method produced symmetrical and sharp peaks with good separation between the process and degradation impurities. The forced degradation study was carried out under acid, base, oxidation, and thermal conditions to demonstrate the stability-indicating capability of the method. The method was validated as per the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) Q2 (R1) and showed excellent specificity, precision, linearity, accuracy, and robustness. The developed HPLC method was precise with a value of 0.25%. The relative standard deviation of accuracy represented by the recovery studies ranged between 89.5% and 104.6%. Linearity analyses indicated a correlation coefficient value of greater than 0.996 for Sugammadex and its known impurities. The LOD and LOQ values for Sugammadex ranged from 0.017% to 0.050%, and for its related impurities, they ranged from 0.015% to 0.055%. The stability of the analytical solution was evaluated and was stable for 75 h when stored at 5 °C. No chromatographic interference was observed during the degradation studies and also in the blank chromatogram.

     

Development and Validation of an HPLC Method for Simultaneous Determination of Ibuprofen and 17 Related Compounds

A reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for determination of ibuprofen and 17 related compounds (chemical process impurities and degradation products) simultaneously. This method may be used for quality control of ibuprofen-containing substances. A number of chromatographic parameters (column, flow rate, temperature, wavelength, gradient elution, buffer solution, and pH) were evaluated. An Agilent ZORBAX Eclipse Plus C18 (250 × 4.6 mm, 5 μm particle size) column at 40 °C was selected on the basis of its separation efficiency and robustness. The column was eluted at 1.0 mL min^?1 with a gradient using 10 mM sodium phosphate buffer at pH 6.9 as mobile phase A and acetonitrile as mobile phase B. The ultraviolet detector was set at 214 nm. This method was validated to confirm its system suitability, specificity, linearity, precision, accuracy, sensitivity, robustness, and sample stability according to international conference on harmonization (ICH) guidelines. This method was applied to analyze seven batches of ibuprofen drug products from different manufacturers.     

Development and Validation of an RP-HPLC Method for Determination of Valganciclovir in Human Serum and Tablets

This paper describes the validation of an isocratic high-performance liquid chromatographic method for the assay of valganciclovir in raw materials, tablets and human serum samples. Valganciclovir and fluvastatin (internal standard) were well separated using a reversed phase column and a mobile phase consisting of a mixture of acetonitrile:methanol:KH₂PO₄ (0.02 M) (40:20:40; v/v/v) (at pH 5.0). The mobile phase was pumped at 1.0 mL min⁻¹ flow rate and valganciclovir was detected by diode-array detection at 255 nm. The retention times for valganciclovir and fluvastatin were 3.41 and 5.60 min, respectively. A linear response (r > 0.999) was observed in the range of 10–30,000 ng mL⁻¹ in mobile phase and serum. The limit of detection and limit of quantification were found as 2.95 and 9.82 ng mL⁻¹ in mobile phase and 1.73 and 5.77 ng mL⁻¹ in human serum samples, respectively. Validation parameters as precision, accuracy, selectivity, reproducibility and system suitability tests were also determined. The method can be used for valganciclovir assay of tablets and human serum samples as the method separates valganciclovir from tablet excipients and endogenous substances.

     

Development and Validation of an SPE-LC Method for the Simultaneous Determination of trans-Resveratrol and Selected Flavonoids in Wine

A simple LC method has been developed for the simultaneous determination of the flavonols rutin, myricetin, quercetin, kaempferol and the stilbene, trans-resveratrol, in wines. Sample clean-up was performed with polymeric Nexus ABS ELUT cartridges. The polyphenols were separated in less than 25 min using gradient elution and UV detection at 320 nm. Average recoveries of the analytes from spiked wine ranged from 82.2 to 117.6% and the detection limits, based on spiked extracted synthetic wine, ranged from 0.02 to 0.2 mgL^?1. The method was applied to the analysis of Greek wines.     

Development and Validation of Stability Indicating LC Method to Quantify Captopril in Tablets of Controlled Release

An accurate, simple, reproducible, and sensitive liquid chromatographic method was developed and validated for the captopril determination in controlled release tablets. The analyses were performed at room temperature on a reversed-phase Phenomenex Luna C₁₈ column (250 mm × 4.6 mm). The mobile phase was composed of water:methanol (45:55; v/v) pH 2.5, and it was eluted isocratically at a 1.0 mL min⁻¹ flow rate. The method was validated in terms of specificity, linearity, quantification limit, detection limit, accuracy, precision and robustness. The response was linear in the range 0.3–1.5 mg mL⁻¹ (r ²  = 0.9983). The relative standard deviation values for inter-and intra-day precision were 0.77% and 0.50%, respectively. Recoveries ranged between 97.7 and 99.1%. The method was successfully applied for the determination of captopril in the developed formulations.     

Development and Validation of Stability Indicating LC Method to Quantify Captopril in Tablets of Controlled Release

An accurate, simple, reproducible, and sensitive liquid chromatographic method was developed and validated for the captopril determination in controlled release tablets. The analyses were performed at room temperature on a reversed-phase Phenomenex Luna C₁₈ column (250 mm × 4.6 mm). The mobile phase was composed of water:methanol (45:55; v/v) pH 2.5, and it was eluted isocratically at a 1.0 mL min⁻¹ flow rate. The method was validated in terms of specificity, linearity, quantification limit, detection limit, accuracy, precision and robustness. The response was linear in the range 0.3–1.5 mg mL⁻¹ (r ² = 0.9983). The relative standard deviation values for inter-and intra-day precision were 0.77% and 0.50%, respectively. Recoveries ranged between 97.7 and 99.1%. The method was successfully applied for the determination of captopril in the developed formulations.

     

Development and Validation of a Stability-Indicating LC Method for Curcumin

A simple, isocratic, stability-indicating liquid chromatographic method for quantitative determination of curcumin was successfully developed. The chromatographic separations were achieved using a Hi-Q-Sil C18; 4.6 mm × 250 mm and 10 μm particle size column employing acetonitrile and acetate buffer (pH 3.0; 60: 40, v/v) as the mobile phase. The analyte was subjected to acidic, basic, oxidative, thermal and photo degradation. The method was validated with respect to linearity, precision, accuracy, limit of detection and limit of quantification. Curcumin was detected by UV-Vis detector at 425 nm whereas the degradation products were detected at 280 nm. The method was linear over the concentration range of 1–10 μg mL^?1. The limit of detection was found to be 0.06 μg mL^?1 and the quantification limit was 0.21 μg mL^?1. Considerable degradation of the analyte was observed when it was subjected to alkaline conditions. Accuracy, evaluated as recovery, was in the range of 97–103%. Intra-day precision and intermediate precision showed relative standard deviations <1% and <2% respectively.