VALIDATED CHIRAL RP-UFLC METHOD FOR THE QUANTIFICATION OF CHLORTHALIDONE IN BULK AND PHARMACEUTICAL DOSAGE FORM

Objective: Development and validation of new, simple and reliable enantioselective reverse phase ultra-fast liquid chromatography (RP-UFLC) method for quantification of chlorthalidone in bulk and pharmaceutical dosage form.Methods: In the present study, the isocratic RP-UFLC method was developed on Phenomenex® Lux cellulose 4 column (250×4.6 mm, 5µ) and di-sodium hydrogen phosphate buffer (pH 3.6): methanol (40:60 v/v) as mobile phase. Elute was monitored at 240 nm with a flow rate of 1 ml/min.Results: The described method provided linear correlation (R2=0.999) between the range of 2-10 µg/ml. Chlorthalidone enantiomers showed good resolution with a retention time (tR) of 5.75 min and 7.46 min respectively. The precision of the method revealed that relative standard deviation is within the acceptable limit. The percentage recovery of each chlorthalidone enantiomers was found to be 99.98% and 100.09% respectively. The method was validated in accordance with ICH harmonized tripartite guidelines, validation of analytical procedures: text and methodology Q2 (R1).Conclusion: An economical, accurate, sensitive and precise RP-UFLC method was developed and fully validated for quality control analysis of chlorthalidone in pharmaceutical dosage form

SIMULTANEOUS ESTIMATION OF CLOPIDOGREL AND ATORVASTATIN IN HUMAN PLASMA USING BIO-ANALYTICAL RP-ULTRA FAST LIQUID CHROMATOGRAPHIC METHOD

This manuscript depicts a simple, accurate, sensitive, precise and robust Ultra fast liquid chromatographic (UFLC) method developed and validated for the simultaneous determination Clopidogrel and Atorvastatin in human plasma as per USFDA draft guidelines. In the current study, the analysis was performed on phenomenex C8 (250 × 4.6 mm, 5μm) column using phosphate buffer (pH-2.5) and acetonitrile (50: 50 v/v) as mobile phase at flow rate of 1.3 mL/min. In the current developed method, Clopidogrel and Atorvastatin eluted at a retention time of 4.06 and 10.31 min respectively. The proposed method is having linearity in the concentration range from 10 to 50μg/mL of Clopidogrel and Atorvastatin. The current method was validated with respect to linearity; precision, lowest limit of detection (LLOD), accuracy and recovery according to the USFDA guidelines. The system consisted of a pump (Shimadzu, prominence, UFLC), with 20 µl sample injector, along with a PDA detector at a wavelength of 243 nm and 220 nm for Atorvastatin and Clopidogrel respectively. Data was compiled using Shimadzu LC Solution software. A good linear relationship over the concentration range of 10-50µg/ml was shown. Validation of the method was carried out as per the USFDA draft guidelines. The method developed was found to be precise, accurate, specific, linear and selective. Statistical analysis shows that the method is selective and reproducible for the estimation of Clopidogrel and Atorvastatin in combined dosage forms

Stability-Indicating UFLC Method For Uncoupling And Estimation Of Impurities In Clopidogrel, Aspirin And Omeprazole In Their Tablet Dosage Form Using PDA Detection: Uncoupling and Estimation of Impurities in Clopidogrel, Aspirin, and Omeprazole

In this paper a fast and novel stability-indicating ultra fast LC method for separation and estimation of impurities in clopidogrel and aspirin in their combined tablet dosage form and omeprazole was developed. The separation of USP related substances of clopidogrel (A, B and C), aspirin (D), omeprazole (A, B and C) and few other unknown impurities was detected by using ultra fast liquid chromatography with PDA detection. The maximum detection was set as follows: 237 nm for aspirin, its impurities and for the impurity C of Clopidogrel and 254 nm for Clopidogrel and its impurities except for impurity C and 280 nm for omeprazole and its impurities. Phenomenex C8 (250 mm × 4.6 mm, 5μ) was used as a stationary column to separate and analyze the mixture within 11 min with a programmed gradient elution of 0.01 M phosphate buffer pH 2.0 and acetonitrile. The method was successfully validated in accordance to the International Conference of Harmonization (ICH) guidelines for clopidogrel and its impurities, aspirin and its impurity D and omeprazole and its impurities A, B and C. The tablets were exposed to acid, alkaline, thermal, higher humidity, oxidative and photolytic stress conditions. Samples undergone stressed conditions were analyzed by the novel proposed method. Separation was satisfactory for all the significant degradation products from the principal peaks of drug substances and the impurities from each other. The method complies for the peak purity test for clopidogrel, aspirin and omeprazole in all the samples under stress and showed no co-elution of degradation products. The method was found to be stable, precise, linear, accurate, sensitive, specific and robust. The method can be used routinely to test the adulteration in the pharmaceutical formulations of clopidogrel, aspirin, and omeprazole

Optimized and Validated RP-UPLC Method for the Determination of Losartan Potassium and Chlorthalidone in Pharmaceutical Formulations

Purpose: A validated ultra performance liquid chromatography (UPLC) method has been developed and validated for the simultaneous determination of losartan potassium and chlorthalidone in pharmaceutical preparations. Methods: Waters-Acquity UPLC system equipped with Auto Sampler, PDA detector and operated with Empower-2 software was used for the present study. Detection was done at wavelength of 230 nm, HSS C18, 100 mm x 2.1x 1.8 μm column with a reverse phase elution and mobile phase composed of A and B mixed in the ratio 56:44 v/v (Where mobile phase A consists of potassium dihydrogen phosphate buffer of pH 3.0 and Mobile phase B consists of acetonitrile and methanol mixed in the ratio of 90:10 v/v) used at a flow rate of 0.4ml per minute. Results: The retention times for losartan potassium and chlorthalidone were observed at 0.72 and 1.89 minutes. The developed method was validated as per ICH guidelines. Linearity ranges were found to be 12.5-125 μg/ml and 3.125-31.25 μg/ml for losartan potassium and chlorthalidone, respectively. Conclusion: This method is fast, accurate, precise and sensitive hence it can be employed for routine quality control of tablets containing both drugs in industries

Chiral separation of (d)- and (l)-enantiomers of doxylamine succinate in rat plasma

AbstractA selective chiral ultra fast liquid chromatography (UFLC-DAD) method was developed and validated to separate and quantify the (d)- and (l)-enantiomers of doxylamine in rat plasma. After extraction of the plasma samples with acetonitrile, the separation of doxylamine succinate enantiomers and internal standard (I.S., diphenhydramine hydrochloride) was achieved on a cellulose Tris (4-chloro,3-methylphenylcarbamate) column with a mobile phase of 20mM ammonium bicarbonate buffer–acetonitrile (65:35v/v) with 0.15% diethylamine in the buffer at a flow rate of 1.0mL/min. The diode array (DAD) detection wavelength was set at 220nm. The peaks obtained were identified as (d) and (l) by injecting the pure (d) form into the liquid chromatography and comparing the chromatograms. The effect of column oven temperature on the retention of doxylamine and mobile phase variables which have an effect on the enantiomers separation like ionic strength, type and concentration of organic modifier was studied. Linear calibration curves were obtained over the range of 100–1400ng/mL in plasma for both enantiomers (R2>0.995). The mean extraction recoveries were 94.5–104.7% of rat plasma. The mean relative standard deviation (RSD%) of accuracy and intra-day and inter-day precision for both enantiomers were ⩽10%. The method can be further applied to determine the pharmacokinetics of (d)- and (l)-enantiomers in rat plasma

Omeprazole and atorvastatin reduces the ability of clopidogrel to inhibit platelet aggregation in patients undergoing percutaneous coronary intervention in a tertiary health care system: A prospective drug–drug interaction study

Background: Clopidogrel, a prodrug is found to be less effective in inhibiting the platelet aggregation when administered along with PPI's in patients undergoing cardiac stent, ST segment elevated Myocardial infarction (STEMI) followed by percutaneous coronary intervention (PCI). Clopidogrel binds to CYP2C19, a hepatic enzyme to get converted to its active metabolite in order to achieve desired pharmacological activity. The cytochrome P450 3A4 which is partially involved in the metabolism of clopidogrel also metabolizes statins, mainly atorvastatin to the greater extent. Methodology: In the current study patients on PPI's with dual antiplatelet therapy and patients on PPI's and statins with dual antiplatelet therapy are considered to understand the potential drug–drug interactions (pDDI) among the South Asian population. Platelet aggregation was measured in 61 patients undergoing coronary artery stent implantation treated with clopidogrel and aspirin along with PPI's and statins. Results: It was observed that omeprazole and atorvastatin, but not pantoprazole and rosuvastatin, inhibited the antiplatelet activity of clopidogrel. The percent platelet aggregation was 72 ± 6 (p = 0.001) and 43 ± 23 (p = 0.027) in the presence of clopidogrel with omeprazole and pantoprazole respectively. Aggregation was found to be 91 ± 4 (p = 0.001) and 12 ± 23 (p = 0.031) in the presence of clopidogrel with atorvastatin and rosuvastatin respectively. Conclusion: A prominent drug–drug interaction was observed with patients on dual antiplatelet therapy along with omeprazole and atorvastatin

Sonochemical synthesis of graphitic carbon nitride-manganese oxide interfaces for enhanced photocatalytic degradation of tetracycline hydrochloride

The present study focuses on the sonochemical synthesis of graphitic carbon nitride-manganese oxide (GCN/MnO2) nanocomposite for photocatalytic degradation of an environmentally hazardous pharmaceutical compound, tetracycline hydrochloride (TcH). The sonochemical synthesis aided in tailoring the morphology of GCN/MnO2. The characterization results of SEM/FESEM, XRD, FTIR, UV-Vis spectra, EIS, CV, etc., revealed on the morphology, composition, crystallinity, and other photo-electro-intrinsic properties of the materials. The synergy of GCN and MnO(2)results in rapid electron transfer, efficient visible-light absorption, and slower electron-hole pair recombination through its photo-responsive traits against TcH. It was noted that similar to 93% TcH (20 mg L-1) degradation was achieved for 30-mg catalyst dose under light-emitting diode (LED) irradiation (9 W, 220 V) in 135-min duration. The TcH mineralization results were well fit to pseudo-first-order kinetics with a rate constant of 0.02 min(-1)(R-2= 0.994). In addition, the composite possessed fair reusability for consequent cycles. Hence, the as-synthesized composite applied for photocatalysis and photoelectrocatalysis fosters a fit-for-purpose and reliable system in the decontamination of TcH in environmental samples

Degradation of doxycycline antibiotics using lanthanum copper oxide microspheres under simulated sunlight

In this study, lanthanum copper oxide was synthesized under hydrothermal techniques and characterized for doxycycline degradation. The catalyst exhibited enhanced photocatalytic doxycycline degradation under visible light owing to its compatible bandgap energy (1.7 eV). The XRD data revealed high crystallinity of the material with no noticeable impurities. Three-dimensional microspheres of varying sizes (average diameter of 2.52 μm) were observed from SEM. EDX confirms the successful synthesis of La2CuO4. The effect of DC concentration, catalyst dosage, and initial pH on the degradation rate of DC was studied methodically. Interestingly, about 85% of doxycycline (10 mg/L) was degraded within 120 min of light-emitting diode irradiation at pH 10. Oxygen vacancies and surface defects were determined through photoluminescence spectra. The recyclability experiments suggested that the catalyst is capable of degrading DC for three consecutive runs. Radical trapping trials suggested that holes (h+), superoxide radicals (●O2−), and hydroxyl radicals (●OH) are involved in the photodegradation of DC. Herein, the novel approach of La2CuO4 synthesis and the efficient visible-light harvesting capability of as-prepared catalyst reveal the potentiality for DC degradation thereby opening a new horizon of research employing La2CuO4 used for various environmental applications.</p