A stability-indicating liquid chromatographic method was developed and validated for quantitative determination of olmesartan medoxomil (OLM) in coated tablets in the presence of degradation products generated under stress conditions. An isocratic LC separation was performed using a Phenomenex RP-18 column using a mobile phase consisting of water:triethylamine:acetonitrile (60:0.3:40 v/v/v, pH adjusted to 6.3 with phosphoric acid). The flow rate was 1.2 mL min−1 and the detection was achieved with a photodiode array detector set at 257 nm. The response was linear over a range of 10.0 to 30.0 μg mL−1 (r = 0.9999). The specificity and stability-indicating capability of the method was verified subjecting the reference substance and drug product to hydrolytic, oxidative, photolytic, and thermal stress conditions. The method showed a good and consistent recovery (100.2%) with low intra- and inter-day relative standard deviation (RSD) (≤1.0%). A considerable degradation occurred in all stress conditions and the degradation product was well resolved from the main peak. There was no interference of the excipients in the determination of the active pharmaceutical ingredient. Thus, the proposed method was found to be stability-indicating and can be used for routine analysis for quantitative determination of OLM in coated tablets without the interference of major degradation products.
相似文献A sensitive and simple HPLC method with fluorimetric detection has been developed for determination of droperidol in pharmaceutical tablets, human serum, and human milk. Chromatography was performed on a 100 mm × 3 mm i.d. C18 column with methanol–water, 30:70 (v/v), pH 3.5, as mobile phase at a flow-rate of 0.8 mL min−1. The injection volume was 5 μL and detection was by monitoring emission at 324 nm after excitation at 283 nm. Droperidol and p-hydroxybenzoic acid (internal standard) eluted after 5.3 and 6.1 min, respectively. The method was validated over the concentration range 1.14 × 10−7 to 9.12 × 10−6 M. Selectivity was good and the limits of detection and quantitation of the method were approximately 3.54 × 10−8 and 1.07 × 10−7 M, respectively, corresponding to 13 and 40 ng mL−1. The applicability of the method to determination of droperidol in pharmaceuticals, human serum, and human milk was demonstrated.
相似文献A new and simple high-performance liquid chromatography with evaporative light scattering detector method for the determination of Kryptofix 2.2.2 (K-222) in the radiopharmaceuticals of 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) and 3′-deoxy-3′-[18F]fluorothymidine ([18F]FLT) was developed. A C18 column was used and the mobile phase was 10 % (v/v) methanol and 90 % (v/v) water (0.1 % trifluoroacetic acid, v/v) at a flow rate of 0.2 mL min−1. The drift tube temperature was 40 °C. The pressure of nebulizing gas (N2) was 3.0 bar. The gain was 10. Good separation of K-222 from main related substances could be achieved. Excellent linearity (r 2 = 0.9995) was obtained over the range of 5–100 μg mL−1. The precision ranged from 0.68 to 5.16 % (RSD) and the accuracy ranged from −3.05 to 2.62 % (RE). The limit of detection was 2 μg mL−1. This method offers simple, rapid and quantitative detection of K-222, thus making it acceptable for routine determination.
相似文献A simple, rapid, and stability-indicating reversed-phase high-performance liquid chromatographic (LC) method for analysis for dutasteride has been successfully developed. Chromatography was performed on a 150 mm × 4.6 mm C18 column with acetonitrile–water 60:40 (v/v) as isocratic mobile phase at 1.0 mL min−1. Ultraviolet detection of dutasteride was at 210 nm. Its retention time was approximately 10 min and its peak was symmetrical. Response was a linear function of concentration over the range 0.2–1 μg mL−1 (R 2 = 0.997) and the limits of detection and quantitation were was 0.05 and 0.10 μg mL−1, respectively. The method was validated for linearity, precision, repeatability, sensitivity, and selectivity. Selectivity was validated by subjecting dutasteride stock solution to photolytic, acidic, basic, oxidative, and thermal degradation. The peaks from the degradation products did not interfere with that from dutasteride. The method was used to quantify dutasteride in pharmaceutical preparations.
相似文献Two new, rapid, precise, accurate and specific chromatographic methods were described for the simultaneous determination of olmesartan medoxomil and hydrochlorothiazide in combined tablet dosage forms. The first method was based on reversed phase liquid chromatography using an Eurosphere 100 RP C18 column (250 × 4.6 mm ID, 5 μm). The mobile phase was methanol–0.05% o-phosphoric acid (60:40 v/v) at a flow rate of 1.0 mL min−1. Commercially available tablets and laboratory mixtures containing both drugs were assayed and detected using a UV detector at 270 nm. The second method involved silica gel 60 F254 high performance thin layer chromatography and densitometric detection at 254 nm using acetonitrile–ethyl acetate–glacial acid (7:3:0.4 v/v/v) as the mobile phase. Calibration curves ranged between 200–600 and 125–375 ng spot−1 for olmesartan and hydrochlorothiazide, respectively.
相似文献This paper discusses the development of a stability-indicating reversed-phase LC method for analysis of cholecalciferol as the bulk drug and in formulations. The mobile phase was acetonitrile–methanol–water 50:50:2 (v/v). The calibration plot for the drug was linear in the range 0.4–10 μg mL−1. The method was accurate and precise with limits of detection and quantitation of 64 and 215 ng, respectively. Mean recovery was 100.71%. The method was used for analysis of cholecalciferol in pharmaceutical formulations in the presence of its degradation products and commonly used excipients.
相似文献A reversed-phase liquid chromatography (RP-LC) method was validated for the determination of rupatadine in pharmaceutical dosage forms. The LC method was carried out on a Gemini C18 column (150 mm × 4.6 mm I.D.), maintained at 30 °C. The mobile phase consisted of ammonium acetate buffer (pH 3.0; 0.01 M) with 0.05% of 1-heptanesulfonic acid–acetonitrile (71.5:28.5, v/v), run at a flow rate of 1.0 mL min−1 and using photodiode array (PDA) detection at 242 nm. The chromatographic separation was obtained with retention time of 5.15 min, and was linear in the range of 0.5–400 μg mL−1 (r 2 = 0.9999). The specificity and stability-indicating capability of the method was proven through the degradation studies and showing also, that there was no interference of the excipients. The accuracy was 100.39% with bias lower than 0.58%. The limits of detection and quantitation were 0.01 and 0.5 μg mL−1, respectively. Moreover, method validation demonstrated acceptable results for precision, sensitivity and robustness. The proposed method was applied for the analysis of pharmaceutical dosage forms assuring the therapeutic efficacy.
相似文献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.
相似文献A simple method for the determination of carbamazepine and its active metabolite carbamazepine-10,11-epoxide by ultra performance liquid chromatography (UPLC) with ultraviolet absorbance detection (TUV) was developed. The method involves a two-step protein precipitation by liquid–liquid extraction. Phenytoin sodium was used as the internal standard. The separation was carried out on Acquity C18 column with acetonitrile:methanol:KH2PO4 buffer (adjusting pH to 4.6 with 85% o-phosphoric acid) (180/180/170, v/v/v) as the mobile phase at a flow rate of 0.4 mL min−1. Linear detection response was obtained for concentrations ranging from 50 to 5,000 ng mL−1. The limit of quantification (LOQ) was 50 ng mL−1. The method was validated successfully for the determination of carbamazepine and its active metabolite carbamazepine-10,11-epoxide, which can be applied through pharmacokinetics and bioequivalence studies.
相似文献This paper describes development and validation of a high-performance liquid chromatographic method for simultaneous analysis of tramadol hydrochloride (TR) and aceclofenac (AC) in a tablet formulation. When the combination formulation was subjected to ICH-recommended stress conditions, adequate separation of TR, AC, and the degradation products formed was achieved on a C18 column with 65:35 (v/v) 0.01 M ammonium acetate buffer, pH 6.5—acetonitrile as mobile phase at a flow rate of 1 mL min−1. UV detection was performed at 270 nm. The method was validated for specificity, linearity, LOD and LOQ, precision, accuracy, and robustness. The method was specific against placebo interference and also during forced degradation. The linearity of the method was investigated in the concentration ranges 15–60 μg mL−1 (r = 0.9999) for TR and 40–160 μg mL−1 (r = 0.9999) for AC. Accuracy was between 98.87 and 99.32% for TR and between 98.81 and 99.49% for AC. Because degradation products were well separated from the parent compounds, the method was stability-indicating.
相似文献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.
相似文献A simple and reliable liquid chromatographic method has been developed and validated for the determination of cefdinir in human urine and capsule samples. A chromatographic separation was achieved on a C18 column using a mobile phase consisting of potassium dihydrogen phosphate (10 mM, pH 4.5)–acetonitrile (90:10, v/v). Quantitation was achieved with UV detection at 285 nm, based on peak area with linear calibration curve at a concentration range of 0.7–39 µg mL−1. This method was successfully applied for the establishment of an urinary excretion pattern after oral dose.
相似文献A validated capillary zone electrophoretic method for analysis of sotalol is described. Analysis was performed in a fused-silica capillary with 20 mM phosphate buffer (pH 4.20) containing 10% (v/v) acetonitrile as background electrolyte. The applied potential was +20 kV, the injection time 0.08 min, signal detection was at 200 nm, and 3,4-dihydoxybenzylamine was used as internal standard. The method was validated over the concentration range 1.98 × 10−5 to 9.90 × 10−5 M; repeatability was good and there was no interference. Highly satisfactory results were obtained from analysis of tablets and serum, indicating the method is specific, accurate, and precise, and suitable for routine analysis of sotalol in pharmaceutical tablets and in pharmacokinetic studies.
相似文献Citalopram, a selective serotonin reuptake inhibitor, is used as an antidepressant agent. In this study an on-line solid phase extraction method with spectrofluorometric detection was developed. Solid phase extraction cartridges contain 200 mg C18 with a particle size of 45 μm. The best solvent system found was consistend of ethanol and 0.1 M acetic acid (40:60, v/v) for elution. The optimized values of injection volume and flow rate were 1 mL and 2.5 mL min−1. The excitation and emission wavelengths were 240 and 300 nm. The calibrations were linear in the concentration range of 1.0 × 10−7–1.5 × 10−6 M in aqueous solution and 2.5 × 10−7–1.2 × 10−6 M in serum. The limit of detection values were 1.6 × 10−8 M for citalopram in tablets and 1.7 × 10−8 M in serum samples. The limit of quantification values were 5.2 × 10−8 M for citalopram in tablets and 5.5 × 10−8 M in serum. The proposed method has been applied successfully for the determination of citalopram HBr in pharmaceutical tablets and also in spiked human serum. The recovery values of the method were 99.5–100.6% for tablets and 98.8–100.9% for serum.
相似文献A stability-indicating ultra-high-performance liquid chromatography (UHPLC) method with a diode array detector was developed and validated for the determination of cis/trans isomers of perindopril l-arginine in bulk substance and pharmaceutical dosage form. The separation was achieved on a Poroshell 120 Hilic (4.6 × 150 mm, 2.7 µm) column using a mobile phase composed of acetonitrile–0.1 % formic acid (20:80 v/v) at a flow rate of 1 mL min−1. The injection volume was 5.0 µL and the wavelength of detection was controlled at 230 nm. The selectivity of the UHPLC-DAD method was confirmed by determining perindopril l-arginine in the presence of degradation products formed during acid–base hydrolysis and oxidation as well as degradation in the solid state, at an increased relative air humidity and in dry air. The method’s linearity was investigated in the ranges 0.40–1.40 µg mL−1 for isomer I and 0.40–2.40 µg mL−1 for isomer II of perindopril l-arginine. The UHPLC-DAD method met the precision and accuracy criteria for the determination of the isomers of perindopril l-arginine. The limits of detection and quantitation were 0.1503 and 0.4555 µg mL−1 for isomer I and 0.0356 and 0.1078 µg mL−1 for isomer II, respectively.
相似文献A simple, stability-indicating, reversed-phase liquid chromatographic method was developed for the determination of lacidipine in the presence of its degradation products. The analysis was carried out using a 150 mm × 4.6 mm i.d., 5 μm particle size Nucleodur MN-C18 column. Mobile phase containing a mixture of acetonitrile and 0.02 M phosphate buffer (70:30) at pH = 5.0 was pumped at a flow rate of 1 mL min−1 with UV-detection at 254 nm. The method showed good linearity in the range of 0.06–15 μg mL−1 with a limit of detection (S/N = 3) of 0.016 μg mL−1 (3.5 × 10−8 M). The suggested method was successfully applied for the analysis of lacidipine in bulk and in commercial tablets with average recoveries of 100.19 ± 0.81% and 100.05 ± 0.69%, respectively. The results were favorably compared to those obtained by a reference method. The suggested method was utilized to investigate the kinetics of alkaline, acidic, peroxide and photo-induced degradation of the drug. The apparent first-order rate constant, half-life times and activation energies of the degradation process were calculated. The pH profile curve was derived. The proposed method was successfully applied to the content uniformity testing of tablets.
相似文献A rapid, sensitive, and specific reverse phase high performance liquid chromatography with diode array detection procedure for the simultaneous determination of abacavir, efavirenz and valganciclovir in spiked human serum is described. Separation was performed on a 5 μm Waters Spherisorb column (250 × 4.6 mm ID) with acetonitrile: methanol:KH2PO4 (at pH 5.00) (40:20:40 v/v/v) isocratic elution at a flow rate of 1.0 mL min−1. Calibration curves were constructed in the range of 50–30,000 ng mL−1 for abacavir and efavirenz, and 10–30,000 ngmL−1 for valganciclovir in serum samples. The limit of detection and limit of quantification concentrations of the HPLC method were 3.80 and 12.68 ng mL−1 for abacavir, 2.61 and 8.69 ng mL−1 for efavirenz, 1.30 and 4.32 ng mL−1 for valganciclovir. The method has been applied, without any interference from excipients or endogenous substances, for the simultaneous determination of these three compounds in human serum.
相似文献A rapid and sensitive reversed-phase high-performance liquid chromatographic method for analysis of fexofenadine in human plasma has been developed and optimized. The analytes were extracted from biological samples by solid-phase extraction on hydrophilic–lipophilic balance cartridges. LC separation was performed on a C18 analytical column (125 mm × 4 mm i.d., 5-μm particles) with 42:58 (v/v) acetonitrile–water adjusted to pH 2.7 with 85% orthophosphoric acid as mobile phase. Fluorescence detection was performed with excitation at 230 nm and emission at 290 nm. The total time for chromatographic separation was 7 min. The method was validated in accordance with EU guidelines by analysis of plasma samples fortified with fexofenadine at concentrations between 0.05 and 800 ng mL−1. Calibration plots were linear in this range. Mean recovery was typically 94.03% and the detection limit was 0.05 ng mL−1. The time required for quantitative analysis is shorter than that required by other methods.
相似文献This paper describes the validation of an isocratic LC method for the assay of linezolid in tablets. Validation parameters such as linearity, precision, accuracy, specificity, limit of detection, limit of quantitation and robustness were determined. LC was carried out by reversed phase technique on an RP-18 column with a mobile phase composed of 1% acetic acid:methanol:acetonitrile (50:25:25, v/v/v). Linezolid and your combination drug product were exposed to acid, base, oxidation, dry heat and photolytic stress conditions. A linear response (r > 0.9999) was observed in the range of 8.0–20.0 μg mL−1. The retention time of linezolid was 4.6 min. The method showed good recoveries and intra- and inter-day relative standard deviations were less than 1.0%. The LOD and LOQ were 0.21 and 0.63 μg mL−1, respectively. The developed LC method for determination of related substances and assay determination of linezolid can be used to evaluate the quality of regular production samples. It can also be used to test the stability samples of linezolid.
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