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1.
A simple, rapid and robust LC method for enantiospecific separation and determination of citalopram in drugs and pharmaceuticals was developed using UV and polarimetric detectors connected in series. Baseline separation with resolution > or = 3.0 was achieved within 20 min on Chiralcel OD-H (250 mm x 4.6 mm) 5 microm column using a mobile phase containing of n-hexane:2-propanol:triethylamine (TEA) (95:05:0.1 v/v/v) at a flow rate of 1.0 ml/min at 25 degrees C. Effects of 2-propanol, triethylamine and temperature on enantioselectivity and resolution of the enantiomers were evaluated. Clopidogrel hydrogen sulphate was used as an internal standard (IS) for quantitative determinations using UV detector at 240 nm. Polarimetric detector was used for identification of enantiomers. The limits of detection (LOD) and quantification (LOQ) were 0.5 and 1.3 microg/ml respectively for both the enantiomers. The linearity of the method was in the range of 50-600 microg/ml with r2 > 0.9999. The inter- and intra-day assay precision was less than 0.63% (%R.S.D.) and recoveries were in the range 99.38-100.41%. The method was validated and found to be suitable for determination enantiomeric purity of citalopram in bulk drugs and pharmaceutical formulations.  相似文献   

2.
A chiral liquid chromatographic method was developed for the enantiomeric resolution of Pramipexole dihydrochloride monohydrate, (S)-2-amino-4,5,6,7-tetra-hydro-6-(propylamino) benzothiazole dihydrochloride monohydrate, a dopamine agonist in bulk drugs. The enantiomers of Pramipexole dihydrochloride monohydrate were resolved on a Chiralpak AD (250 mm x 4.6 mm, 10 microm) column using a mobile phase system containing n-hexane:ethanol:diethylamine (70:30:0.1, v/v/v). The resolution between the enantiomers was found not less than eight. The presence of diethylamine in the mobile phase has played an important role in enhancing chromatographic efficiency and resolution between the enantiomers. The developed method was extensively validated and proved to be robust. The limit of detection and limit of quantification of (R)-enantiomer were found to be 300 and 900 ng/ml, respectively for 20 microl injection volume. The percentage recovery of (R)-enantiomer was ranged from 97.3 to 102.0 in bulk drug samples of Pramipexole dihydrochloride monohydrate. Pramipexole dihydrochloride monohydrate sample solution and mobile phase were found to be stable for at least 48 h. The proposed method was found to be suitable and accurate for the quantitative determination of (R)-enantiomer in bulk drugs.  相似文献   

3.
A new and accurate chiral liquid chromatographic method was developed for the enantiomeric resolution of Rivastigmine hydrogen tartarate, (-)S-N-ethyl-3-[(1-dimethyl-amino)ethyl]-N-methylphenyl-carbamate hydrogen tartarate, a cholinesterase inhibitor in bulk drugs. The enantiomers of Rivastigmine hydrogen tartarate were baseline resolved on a Chiralcel OD-H (250 mm x 4.6 mm, 5 microm) column using a mobile phase system containing hexane: isopropanol: trifluoroacetic acid (80:20:0.2, v/v/v). The resolution between the enantiomers was not less than four and interestingly distomer was eluted prior to eutomer in the developed method. The presence of trifluoroacetic acid in the mobile phase has played an important role in enhancing chromatographic efficiency and resolution between the enantiomers. The developed method was extensively validated and proved to be robust. The limit of detection and limit of quantification of (R)-enantiomer were found to be 500 and 1500 ng/ml, respectively for 10 microl injection volume. The percentage recovery of (R)-enantiomer was ranged from 95.2 to 104.3 in bulk drug samples of Rivastigmine hydrogen tartarate. Rivastigmine hydrogen tartarate sample solution and mobile phase were found to be stable for at least 48 h. The proposed method was found to be suitable and accurate for the quantitative determination of (R)-enantiomer in bulk drugs. Chiralcel OJ-H column can also be used as an alternative for the above purpose.  相似文献   

4.
A new and accurate chiral liquid chromatographic method was described for the enantiomeric separation of ZTR-5 [(4S)-4-(4-aminobenzyl)-2-oxazolidinone, (S)-isomer], a key intermediate of Zolmitriptan in bulk drugs. The enantiomers of ZTR-5 were baseline resolved on a Chiralpak AD-H (250 mm x 4.6 mm, 5 microm) column using a mobile phase system containing hexane:ethanol (70:30, v/v). The resolution between the enantiomers was not less than four and interestingly distomer was eluted prior to eutomer. The limit of detection and limit of quantification of (4R)-4-(4-aminobenzyl)-2-oxazolidinone [(R)-isomer] were found to be 250 and 750 ng/ml, respectively, for 10 microl injection volume. The percentage recovery of (R)-isomer ranged from 92.0 to 105.6 in the bulk drug samples of ZTR-5. The validated method yielded good results regarding precision, linearity, accuracy and ruggedness. The proposed method was found to be suitable and accurate for the quantitative determination of (R)-isomer in bulk drug samples of ZTR-5.  相似文献   

5.
A chiral high performance liquid chromatographic method was developed and validated for the enantiomeric resolution of Valacyclovir, L-valine 2-[(2-amino-1,6-dihydro-6-oxo-9h-purin-9-yl) methoxy] ethyl ester, an antiviral agent in bulk drug substance. The enantiomers of Valacyclovir were resolved on a Chiralpak AD (250 mm x 4.6 mm, 10 microm) column using a mobile phase system containing n-hexane: ethanol: diethylamine (30:70:0.1, v/v/v). The resolution between the enantiomers was found not less than four. The presence of diethylamine in the mobile phase has played an important role in enhancing chromatographic efficiency and resolution between the enantiomers. The developed method was extensively validated and proved to be robust. The limit of detection and limit of quantification of (D)-enantiomer were found to be 300 and 900 ng/ml, respectively, for 20 microL injection volume. The calibration curve showed excellent linearity over the concentration range of 900 ng/ml (LOQ) to 6000 ng/ml for (D)-enantiomer. The percentage recovery of (D)-enantiomer was ranged from 97.50 to 102.18 in bulk drug samples of Valacyclovir. Valacyclovir sample solution and mobile phase were found to be stable for at least 48 h. The proposed method was found to be suitable and accurate for the quantitative determination of (D)-enantiomer in bulk drugs substance. It can be also used to test the stability samples of Valacyclovir.  相似文献   

6.
An enantioselective high-performance liquid chromatographic method for determination of enantiomers of mosapride citrate in bulk drugs and pharmaceuticals using UV-vis and polarimetric detectors in series has been developed. Baseline separation with resolution >2.0 was achieved on a column containing amylose tris-(3,5-dimethylphenylcarbamate) as stationary phase using a mobile phase consisting of n-hexane:ethanol:triethylamine (80:20:0.3, v/v/v) at 40 degrees C. The detection was carried out at UV-276 nm and enantiomers were identified by polarimetric detector. The effect of ethanol, 2-propanol, TEA, temperature and mobile phase flow rate on separation of MSP enantiomers was studied and the method was validated with respect to accuracy, precision, linearity and limits of detection and quantification. The linearity of the method was studied between 6.25 and 50 microg/ml and r2 was >0.9997. The recoveries were in the range 99.63-100.22%, the method was suitable not only for process development of mosapride citrate but also for quality assurance of the individual enantiomers in bulk drugs and pharmaceuticals.  相似文献   

7.
A high-performance liquid chromatographic method was developed for separation of the enantiomers of efavirenz. The developed method was applied for the determination of (R)-enantiomer in (S)-efavirenz and satisfactory results were achieved. The base line separation with a resolution of more than 4.0 was achieved on Chiralcel OD (250 mm x 4.6 mm, 10 microm) column containing tris-(3,5-dimethylphenylcarbomate) as stationary phase. The mobile phase consists of n-hexane: isopropyl alcohol (80:20 v/v) with 0.1% (v/v) of formic acid as additive. The flow rate was kept at 1.0 ml/min and the UV detection was monitored at 254 nm. The (R)-enantiomer was found linear over the range of 0.1 microg/ml--6 microg/ml. The limit of detection (LOD) was 0.03 microg/ml and the limit of quantification (LOQ) was 0.1 microg/ml (n=3. The precision of (R)-enantiomer at LOQ level was evaluated through six replicate injections and the RSD of the peak response was achieved as 1.34%. The results demonstrated that the developed LC method was simple, precise, robust and applicable for the purity determination of efavirenz.  相似文献   

8.
A sensitive and stereospecific high-performance liquid chromatography (HPLC) method for determination of sertraline in bulk drug, tablets and capsules was developed. Chromatography resolution of the sertraline enantiomeric forms and trans diastereoisomers was performed on Alltima C18 (250 mm x 4.6mm i.d., 5 microm) column with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) as mobile phase additive. The composition of the mobile phase was 68:32 (v/v) aqueous 170 mM phosphate buffer, pH 3.0 (adjusted with 85% phosphoric acid) containing 18 mM HP-beta-CD/acetonitrile at a flow rate of 1.0 ml x min(-1). The UV detector was set at 225 nm. Calibration curves were linear (r=0.9999, n=9) in the range of 1-120 microgml (-1) for sertraline. Limit of detection and quantitation for sertraline was 0.029 and 0.097 microg x ml (-1). The values of R.S.D. of repeatability and intermediate precision for bulk drug, tablets and capsules of sertraline hydrochloride were less than 1.0%.  相似文献   

9.
A enantioselective reversed-phase high performance liquid chromatographic method was developed for the enantiomeric resolution of safinamide mesilate, 2(S)-[4-(3-fluorobenzyloxy)benzylamino] propionamide methanesulfonate, a neuroprotectant with antiparkinsonian and anticonvulsant activity for the treatment of Parkinson disease. The enantiomers of safinamide mesilate were baseline resolved on a Chiralcel OD-RH (150mm×4.6mm, 5μm) column using a mobile phase system containing 300mM sodium di-hydrogen phosphate buffer (pH 3.0):methanol:acetonitrile (65:25:10, v/v/v). The resolution between the enantiomers was not less than 3.0. The pH value of buffer solution in the mobile phase has played a key role in enhancing chromatographic efficiency and resolution between the enantiomers. The developed method was validated and proved to be robust. The limit of detection and limit of quantification of (R)-enantiomer were found to be 15 and 50ng/mL, respectively, for 20μL injection volume. The percentage recovery of (R)-enantiomer was ranged from 94.2 to 103.7 in bulk drug samples of safinamide mesilate. The sample solution and mobile phase were found to be stable at least for 48h. The final optimized method was successfully applied to separate (R)-enantiomer from safinamide mesilate and was proven to be reproducible and accurate for the quantitative determination of (R)-enantiomer in bulk drugs.  相似文献   

10.
High-performance liquid chromatographic methods for separation of racemic doxazosin mesylate and its synthetic precursors on polysaccharide based stationary phases viz., amylose tris-(3,5-dimethylphenylcarbamate) (Chiralpak AD-H) and cellulose tris-(3,5-dimethylphenylcarbamate) (Chiralcel OD-H) were developed. The base line separation with Rs>1.50 was obtained using a mobile phase containing n-hexane-alcohol-0.1% diethylamine (ethanol, 1-propanol and 2-propanol) in various proportions. The effect of concentration of the alcoholic modifiers on the resolution was studied. A good separation was achieved on amylose based Chiralpak AD-H column when compared with cellulose based Chiralcel OD-H. The effects of structural features of the solutes and solvents on discrimination between the enantiomers were examined. The detection was carried out at 240 nm with UV detector while identification by polarimetric detector connected in series. The method was suitable not only for process development of doxazosin mesylate but also determination of enantiomeric purity of bulk drugs and pharmaceuticals.  相似文献   

11.
A reversed-phase high-performance liquid chromatographic method was developed for determination of process impurities and degradation products of bicalutamide in bulk drug and pharmaceutical formulations. The separation was accomplished on a Symmetry C(18) (4.6 mm x 250 mm; particle size 5 microm) column under isocratic mode. The mobile phase was 0.01 M KH(2)PO(4) (pH 3.0):acetonitrile (50:50 v/v) and a PDA detector set at 215 nm was used for detection. Forced degradation of bicalutamide was carried out under thermal, photo, acidic, alkaline and peroxide conditions. The unknown process impurities and alkaline degradation products were isolated and characterized by ESI-MS/MS, (1)H NMR and FT-IR spectral data. Under alkaline conditions bicalutamide was degraded in to an acid and an amine. The kinetics of degradation was studied. The proposed method was validated and successfully applied to the analysis of commercial formulations. Thus, the developed method can be used for process development as well as quality assurance of bicalutamide in bulk drug and pharmaceutical formulations.  相似文献   

12.
A simple and sensitive column-switching high-performance liquid chromatographic method for the simultaneous determination of warfarin enantiomers and their metabolites, 7-hydroxywarfarin enantiomers, in human plasma is described. Warfarin enantiomers, 7-hydroxywarfarin enantiomers, and an internal standard, diclofenac sodium, were extracted from 1 mL of a plasma sample using diethyl ether-chloroform (80:20, v/v). The extract was injected onto column I (TSK precolumn BSA-C8, 5 microm, 10 mm x 4.6 mm inside diameter) for cleanup and column II (Chiralcel OD-RH analytical column, 150 mm x 4.6 mm inside diameter) coupled with a guard column (Chiralcel OD-RH guard column, 10 mm x4.6 mm inside diameter) for separation. The mobile phase consisted of phosphate buffer-acetonitrile (84:16 v/v, pH 2.0) for clean-up and phosphate buffer-acetonitrile (45:55 v/v, pH 2.0) for separation. The peaks were monitored with an ultraviolet detector set at a wavelength of 312 nm, and total time for chromatographic separation was approximately 25 minutes. The validated concentration ranges of this method were 3 to 1000 ng/mL for (R)- and (S)-warfarin and 3 to 200 ng/mL for (R)- and (S)-7-hydroxywarfarin. Intra- and interday coefficients of variation were less than 4.4% and 4.9% for (R)-warfarin and 4.8% and 4.0% for (S)-warfarin, and 5.1% and 4.2% for (R)-7-hydroxywarfarin and 5.8% and 5.0% for (S)-7-hydroxywarfarin at the different concentrations. The limit of quantification was 3 ng/mL for both warfarin and 7-hydroxywarfarin enantiomers. This method was suitable for therapeutic drug monitoring of warfarin enantiomers and was applied in a pharmacokinetic study requiring the simultaneous determination of warfarin enantiomers and its metabolite, 7-hydroxywarfarin enantiomers, in human volunteers.  相似文献   

13.
A simple and precise high performance liquid chromatographic method has been developed and validated for the simultaneous determination of bisoprolol fumarate (BF), and hydrochlorothiazide (HCTZ) in a tablet formulation. Chromatography was carried out at 25 degrees C on a 4.6 mm x 250 mm, 5 microm cyano column with the isocratic mobile phase of 0.1M aqueous phosphate buffer, acetonitrile and tetrahydrofuran (85:10:5, v/v/v) at a flow rate of 1.0 ml/min. The UV detection was carried out at 225 nm. HCTZ and BF were separated in less than 10 min with good resolution and minimal tailing, without interference of excipients. The method was validated according to ICH guidelines and the acceptance criteria for accuracy, precision, linearity, specificity and system suitability were met in all cases. The method was linear in the range of 50-150 microg/ml for BF and 125-375 microg/ml for HCTZ.  相似文献   

14.
A sensitive, simple, specific, precise, accurate and rugged method for determination of enantiomeric purity of S-(-)-1-cyclopropyl-6-fluoro-1,4-dihydro-8-methoxy-7-{4-amino-3,3-dimethylpiperidin-1-yl}-4-oxo-quinoline-3-carboxylic acid hydrochloride monohydrate, WCK 1152, a new drug substance has been developed. The method is based on prederivatization of analyte to diastereomer followed by RP-HPLC using endcapped C-18 stationary phase. Column was maintained at 30°C. The UV/Vis detector was operated at 290 nm. Flow rate of the mobile phase was 1.25 ml/min. The method offers excellent separation of two enantiomers with resolution more than 4 and tailing factor less than 1.5. The method was validated for the quantification of R-(+)-enantiomer impurity, WCK 1153 in the bulk drug. Calibration curves showed excellent linearity over the concentration range of 0.1 to 1.5 mg/ml for WCK 1152 and 0.01 to 0.15 mg/ml for WCK 1153. Precision of the method was 1.13%. Limit of detection and limit of quantitation of the method for WCK 1152 were 0.0006 mg/ml and 0.0018 mg/ml and for WCK 1153 were 0.0007 mg/ml and 0.0021 mg/ml, respectively. Average recovery of the WCK 1153 in WCK 1152 was 94.4%. This method was employed in determining enantiomeric purity of clinical trial batches of WCK 1152.  相似文献   

15.
A rapid and specific high-performance liquid chromatographic method was developed and validated for the simultaneous determination of ketoprofen, valsartan and pantoprazole in human plasma. Chromatographic separation of ketoprofen, valsartan and pantoprazole was performed using a Chromasil C18 column (250 mm x 4.6 mm i.d., 5 microm particle size). The mobile phase consisted of a mixture of 0.02 M sodium dihydrogen phosphate buffer (pH 3.15) and acetonitrile (58:42, v/v) pumped through the chromatographic system at a flow rate of 1 mL x min(-1). The Diode Array detector was operated at 225 and 272 nm. Rofecoxib was used as an internal standard. Sample treatment procedure consisted of deproteinisation with acetonitrile-methanol (50:50 v/v). Analytical recoveries were in the range of 79.00-118.00% of nominal values of valsartan, ketoprofen and pantoprazole. The method was reproducible and accurate with lower limits of quantification 250 microg x L(-1) for pantoprazole and 500 microg x L(-1) for ketoprofen and valsartan. This method was relatively easy to perform and allows simultaneous determination of these three drugs in plasma at nanogram levels.  相似文献   

16.
A simple, rapid, selective and reproducible LC method for separation and quantitative determination of citadiol (CTD), a key intermediate of escitalopram has been developed. An optimum resolution > 3.0 was achieved on Chiralpak AD-H (250 mm x 4.6 mm); 5 microm column connected with UV and polarimetric detectors in series. The effects of organic modifiers, viz., methanol, ethanol, n-propanol and 2-propanol on enantioselectivity were evaluated. The limits of detection (LOD) and quantification (LOQ) were 0.02 microg/ml, 0.03 microg/ml and 0.07 microg/ml, 0.10 microg/ml for R-CTD and S-CTD enantiomers, respectively. The linearity of the method was studied in the range of 0.07-300 microg/ml and 0.1-300 microg/ml for R-CTD and S-CTD, respectively and the r2 was > or = 0.9999. The inter- and intra-day assay precision was less than 0.74% (%R.S.D.) and the recoveries were in the range 99.68-100.72% with %R.S.D. < 0.49%.  相似文献   

17.
The enantiomeric resolution of (+/-)-cizolirtine, (+/-)-cizolirtine-N-oxide, (+/-)-N-desmethylcizolirtine and (+/-)-5(alpha-hydroxybenzyl)-1-methylpyrazole was achieved on amylose tris (3,5-dimethylphenyl carbamate) chiral stationary phase known as Chiralpak AD using hexane/2-propanol/triethylamine (80:20:0.05, v/v/v) as the mobile phase. The flow rate of the mobile phase used was 1.0 ml/min with UV detection at 230 nm. The values of R(s) of the resolved enantiomers of (+/-)-cizolirtine, (+/-)-cizolirtine-N-oxide, (+/-)-N-desmethylcizolirtine and (+/-)-5(alpha-hydroxybenzyl)-1-methyl pyrazole were 1.20, 0.60, 1.16 and 1.15, respectively.  相似文献   

18.
An isocratic reversed-phase high-performance liquid chromatographic (RP-HPLC) method for determination and evaluation of purity of mosapride citrate in bulk drugs and pharmaceuticals has been developed using Waters Symmetry C(18) column with acetonitrile:0.024 M orthophosphoric acid (28:72, v/v) adjusted to pH 3.0 with triethylamine and photodiode array detector set at 276 nm. The method is simple, rapid, selective and capable of detecting all process related impurities at trace levels in the finished products with detection limits ranging in between 0.2 x 10(-8)g and 6.4 x 10(-8)g. The method has been validated with respect to accuracy, precision, linearity, ruggedness, and limit of detection and quantification. The linearity range was 125-1000 microg/ml. The percentage recoveries from pharmaceutical dosages were ranged from 95.53 to 100.7. The method was found to be suitable not only for monitoring the reactions during the process development but also quality assurance of mosapride citrate.  相似文献   

19.
An HPLC method was developed and validated for the determination of cetirizine dihydrochloride (CZ) as well as its related impurities in commercial oral solution and tablet formulations. Furthermore, two preservatives associated with the drug formulations, namely, propyl (PP) and butylparabens (BP) were successfully determined by this method. The chromatographic system used was equipped with a Hypersil BDS C18, 5 microm column (4.6 x 250 mm) and a detector set at 230 nm in conjunction with a mobile phase of 0.05 M dihydrogen phosphate:acetonitrile:methanol:tetrahydrofuran (12:5:2:1, v/v/v/v) at a pH of 5.5 and a flow rate of 1 ml min(-1). The calibration curves were linear within the target concentration ranges studied, namely, 2 x 10(2) - 8 x 10(2) microg ml(-1) and 1-4 microg ml(-1) for CZ, 20-100 microg ml(-1) for preservatives and 1-4 microg ml(-1) for CZ related impurities. The limits of detection (LOD) and quantitation (LOQ) for CZ were, respectively, 0.10 and 0.34 microg ml(-1) and for CZ related impurities were in the ranges of 0.08-0.26 microg ml(-1) and 0.28-0.86 microg ml(-1), respectively. The method proved to be specific, stability indicating, accurate, precise, robust and could be used as an alternative to the European pharmacopoeial method set for CZ and its related impurities.  相似文献   

20.
A new, accurate and reliable chiral HPLC method was developed for the determination of Zolmitriptan, (4S)-4-[[3-[2-(dimethylamino)ethyl]-1H-indol-5-yl] methyl]-2-oxazolidinone an antimigraine agent and its potential impurities namely (4R)-4-[[3-[2-(dimethylamino)ethyl]-1H-indol-5-yl] methyl]-2-oxazolidinone [(R)-enantiomer] and (4S)-4-(4-aminobenzyl)-2-oxazolidinone (Imp-1) in pharmaceutical formulations and in bulk drugs. HPLC separation was carried out by normal phase chromatography with a mobile phase composed of hexane:isopropanol:methanol:diethylamine in the ratio (75:10:15:0.1, v/v/v/v) pumped at a flow rate of 1.0 ml/min on a Chiralpak AD-H column. Zolmitriptan and its potential impurities were baseline resolved in the optimized method. The presence of diethylamine in the mobile phase has played a key role in achieving chromatographic resolution between the enantiomers and also in enhancing chromatographic efficiency. The developed method was also found to be selective under exposed conditions UV light and 60 degrees C. The developed method was completely validated and proved to be robust. The values of the limit of detection (LOD) and limit of quantification (LOQ) of (R)-enantiomer and Imp-1 were 100, 250 ng/ml and 30, 1000 ng/ml, respectively, for 10 microl injection volume. The validated method yielded good results regarding selectivity, linearity, precision, accuracy and ruggedness. Zolmitriptan sample solution and mobile phase are found to be stable for at least 24 h. The proposed method was found to be suitable and accurate for the quantitative determination of Zolmitriptan and its impurities namely (R)-enantiomer and Imp-1 in bulk drugs and commercial formulations.  相似文献   

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