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Two sensitive and validated methods were developed for determination of a racemic mixture citalopram and its enantiomer S-(+) escitalopram. The first method was based on direct measurement of the intrinsic fluorescence of escitalopram using sodium dodecyl sulfate as micelle enhancer. This was further applied to determine escitalopram in spiked huma...
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... ( Fig. 1) a selective serotonine re-uptake inhibitor (SSRI), has been used for the treatment of depression, social anxiety disorder, panic disorder and obsessive-compulsive disorder. [1][2][3] Citalopram is sold as a racemic mixture, consisting of 50% R-(−)-citalopram and 50% S-(+)-citalopram. As the S-(+) enantiomer has the desired ...
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The aim of this study was to analyze the patent protection policy of citalopram as an example for protection of a biologically active chiral structure. A three-step search methodology of patent expiration date, EPO database was performed, and an expanded search was done via the INPADOC patent family system. The patents found were systematized accor...
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... Blood samples were collected from the fundus venous plexus at predetermined periods of time. BER concentration was quantified by the method of micelle-enhanced fluorimetric determination as described by Taha et al. (2009) (Taha et al., 2009), using a fluorescence spectrophotometer (F-4600, Hitachi, Japan) with 355 nm excitation and 535 nm emission, and sodium dodecyl sulfate (SDS) as the fluorescent sensitizer. The methodological investigations of linear range, average recovery, precision, exclusivity and stability were also examined. ...
... Blood samples were collected from the fundus venous plexus at predetermined periods of time. BER concentration was quantified by the method of micelle-enhanced fluorimetric determination as described by Taha et al. (2009) (Taha et al., 2009), using a fluorescence spectrophotometer (F-4600, Hitachi, Japan) with 355 nm excitation and 535 nm emission, and sodium dodecyl sulfate (SDS) as the fluorescent sensitizer. The methodological investigations of linear range, average recovery, precision, exclusivity and stability were also examined. ...
ABSTRACT
Background: Traditional Chinese Medicine decoctions (TCMDs) can be used to prepare outstanding pharmaceutical preparations by the patient themselves. Small molecular active ingredients and macromolecular polysaccharides are inevitably co-existed in TCMDs. Different from the pharmacological synergies among small molecules, the macromolecular polysaccharides in TCMDs might contribute to disease treatment in several ways, although it is frequently overlooked.
Hypothesis/Purpose: This study proposes that the oral bioavailability of the water-insoluble alkaloids of Coptis chinensis Franch. (Ranunculaceae) (C. chinensis) decoction may be attributed to the co-existing C. chinensis polysaccharides (CCPs) dynamically influencing the small intestine microenvironment and regulating the modulation of the paracellular absorption pathway.
Methods: First, the effects of CCPs on the oral bioavailability of the main active ingredient of C. chinensis, berberine, were evaluated in vivo. Next, a series of in situ experimental models of intestinal perfusion and models of isolated jejunal mucosa, Caco-2 cell monolayer membranes, and microfold-like cells were established to assess the correlation among CCPs, intestinal mucosal immunity, and paracellular absorption in the small intestine.
Results: It was observed that CCPs could be endocytosed by the microfold cells on the surface of Peyer's patches, allowing CCPs to activate the lymphocytes, modulate the balance of Th1/Th2, control the secretion of immune effectors IFN-γ and IL-4, and finally regulate the tight junctions in the intestinal epithelial cells. This was a dynamic process with the movement of CCPs in the gastrointestinal tract that altered the flora distribution and functioning of the TLR/NF-κB signal pathway in the small intestine.
Conclusion: The dynamical regulation of CCP on the immune microenvironment of small intestine is responsible for its promotion on the health controlling effects of C. chinensis in traditional dosage forms of decoction.
... AE 4.28. Taha et al. [143] developed a sensitive and validated TLC method for the detection of a racemic mixture citalopram and its enantiomer S-(þ) escitalopram. Chromatograms were developed in clean, dry, paper-lined glass chambers (12 Â 24 Â 24 cm) pre-equilibrated with developer for 10 min. ...
... Escitalopram oxalate (ESC) has high effectivity for the treatment of major depressive episodes and generalized anxiety disorders explaining its pharmacological and clinical applications. [1][2][3] Various reported methods have been employed for determination of ESC, including chromatography, [4][5][6][7][8][9][10][11][12][13][14][15][16] fluorimetry, 14 spectrophotometry, [15][16][17][18][19][20][21] chemiluminescence, 22 capillary electrophoresis, 23,24 potentiometry, 25,26 and voltammetry. 27 Some electron acceptor reagents such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), 7,7,8,8-tetracyano-quinodimethane (TCNQ), tetracyanoethylene (TCNE) and chloranil (CA) can be used in electroanalytical field as mediators or electrode modifiers. ...
... Escitalopram oxalate (ESC) has high effectivity for the treatment of major depressive episodes and generalized anxiety disorders explaining its pharmacological and clinical applications. [1][2][3] Various reported methods have been employed for determination of ESC, including chromatography, [4][5][6][7][8][9][10][11][12][13][14][15][16] fluorimetry, 14 spectrophotometry, [15][16][17][18][19][20][21] chemiluminescence, 22 capillary electrophoresis, 23,24 potentiometry, 25,26 and voltammetry. 27 Some electron acceptor reagents such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), 7,7,8,8-tetracyano-quinodimethane (TCNQ), tetracyanoethylene (TCNE) and chloranil (CA) can be used in electroanalytical field as mediators or electrode modifiers. ...
A sensitive voltammetric method was described for the determination of escitalopram oxalate based on electrocatalytic
oxidation at nickel nanoparticles modified chloranil carbon paste sensor in Britton-Robinson buffer (pH range from 2 to
10). The modified electrode was characterized by scanning electron microscopy, electrochemical impedance and cyclic
voltammetry. The investigation of electrochemical behavior of escitalopram oxalate was performed using cyclic voltam-metry and differential pulse voltammetry. The anodic peak current showed a linear range from 1.0 × 10
–6
to 7.0 × 10
–5
mol L
–1
. The detection limit is below 2.0 × 10
–7
mol L
–1. The proposed method is rapid, economical, simple, precise and
sensitive voltammetric method for the determination of escitalopram oxalate in bulk, dosage form and urine.
... A literature survey revealed that ESC is official in Indian pharmacopoeia and ETZ is official only in Japanese Pharmacopoeia [7,8]. The literature survey revealed that some Spectrophotometric [9], HPTLC [10][11][12], colorimetric [13] HPLC [14][15], fluorimetry [16], LC-MS [17][18][19], CE [20] and TLC [21] methods used for estimation of ESC either individually or in combination with other drugs. Literature survey also reports few HPLC [22], HPTLC [23], LC-MS [24] and GC-MS methods for estimation of ETI individually or in combination with other drugs. ...
The present work describes a simple, selective, rapid, accurate and economic method which has been developed and validated for simultaneous estimation of Escitalopram oxalate (ESC) and Etizolam (ETZ) in tablet dosage form by reverse phase Ultra Performance Liquid Chromatography (RP-UPLC) with PDA detector. The chromatographic separation was carried out on a column Symmetry C 18 (4.6×50mm, 5microm) by using mobile phase mixture of buffer (pH was adjusted at3 by using ortho phosphoric acid) and acetonitrile at ratio of 85:15 v/v at a flow rate 0.5 ml/min. The PDA detection made at 230 nm. The retention time is for Escitalopram oxalate and Etizolam was found 0.752 ±0.002 min & 2.612 ±0.003 min respectively with a run time of 4 minute and resolution of 22.41. Calibration plots were linear over the concentration ranges 80-120 μg/ml and 8-12 μg/ml for ESC and ETZ respectively. The developed method was validated in terms of linearity, accuracy, precision, limit of detection, limit of quantitation and robustness as per ICH guidelines given for analytical method validation and the method was also found to be simple, sensitive, accurate and precise.
... Escitalopram is a single isomer of the pure Senantiomer for the racemic phthalane bicyclic derivative of citalopram. Escitalopram oxalate has a chemical structure S-(+)-1- Literature survey showed several methods for the determination of escitalopram including chromatographic HPLC 3-6 , HPTLC 7-10 , TLC 11 , spectrophotometric [12][13][14][15][16][17][18] , fluorimetry [19][20] , LC-MS [21][22][23][24] , LC-MS/MS 25 , enantiomeric separation 26 , CE 27 and only one ISE method 28 . A major advantage of ISE is that it can be used very rapidly without having to change range to measure samples with large batches covering wide concentrations range. ...
Hepatitis C virus is one of the main causes of chronic hepatitis in developing countries. There are 170 million affected people around the world as reported by the World Health Organization. Nowadays we are looking for monitoring the advanced tools during the most recent of the shortage reagent and equipments troubles which are strongly variables. This work studies the evaluation of diagnosis Hepatitis C and human immunodeficiency viruses diseases by Serum Protein Electrophoresis (SPE) as a marker. SPE designing is as to separate serum protein to five fractions (Albumin, Alpha-1, Alpha-2, Beta, and Gamma) to estimate its individual concentration of the five fractions for the viral infected samples. The elevated serum protein, particularly in the gamma-globulin fraction is frequently associated with HIV infection. All the samples were compared to control samples. It was found that the HCV and HIV infections caused irregular alterations in the electrophoretic protein patterns in serum of the HCV and HIV patients. These alterations were represented at the protein level by disappearance of normal protein bands and / or appearance of abnormal unique bands. Native proteins expressed as a result of the infection with HCV and HIV was detected electrophoretically by vertical polyacrylamide gel electrophoresis.
... Escitalopram is a single isomer of the pure Senantiomer for the racemic phthalane bicyclic derivative of citalopram. Escitalopram oxalate has a chemical structure S-(+)-1- Literature survey showed several methods for the determination of escitalopram including chromatographic HPLC 3-6 , HPTLC 7-10 , TLC 11 , spectrophotometric [12][13][14][15][16][17][18] , fluorimetry [19][20] , LC-MS [21][22][23][24] , LC-MS/MS 25 , enantiomeric separation 26 , CE 27 and only one ISE method 28 . A major advantage of ISE is that it can be used very rapidly without having to change range to measure samples with large batches covering wide concentrations range. ...
Preparation and construction of a new polyvinyl chloride PVC-membrane and chemically modified carbon paste (CMCP) sensors based on ion-pair exchanger escitalopram-silicotungstic (Es-ST) (Sensor 1) and escitalopram-silicomolybdic (Es-SM) (Sensor 2). The effect of several plasticizers and composition of ion-exchangers on the performance characteristics of the sensors was studied. Sensors(1, 2) with 1% composition and dioctyl phthalate (DOP) as plasticizer in PVC-membrane showed Nernstian slopes ranged from 57.5-59.5 ±0.1 mV/decade over the concentration ranged from 5.0 x 10-7-1.0 x 10-2 M with the life span not less than two months and pH 2.5-7.5 with a detection limit 0.1 nM. While in (CMCP) sensors (1, 2) exhibited with 3% composition and tricresylphthalate (TCP) as binder an excellent Nernstian slopes 59.5, 60.5±0.5 mV/decade for 1 and 2 respectively and a wide concentration range from 1.0 x 10-7-1.0 x 10-2 M and pH 2.5-7.5 with a detection limit 0.5 nM. The sensors reflected high selectivity towards different anions, cations, sugars and amino acids and was recommended by IUPAC. The standard addition, the calibration curve and potentiometric titration methods were used for determination escitalopram in its bulk powder, pharmaceutical tablets Cipralex, human plasma/urine and monitoring profile for the tablet in vitro-dissolution rates. The recoveries were excellent and with good agreement compared with British Pharmacopoeia.
... A series of the separation and detection techniques has been applied to the analysis of citalopram or escitalopram in pharmaceutical dosage forms or biological fluids, such as HPLC (10)(11)(12)(13), capillary electrophoresis (14)(15)(16)(17)(18)(19), and TLC (20,21). Isolation, characterization, and structure elucidation of the degradation products of citalopram and the process-related impurities were performed using LC/electrospray ionization (ESI)-MS (22,23), and the hyphenated techniques LC/MS/MS, NMR spectroscopy, and FTIR spectroscopy (24)(25)(26). ...
In this study, the RP-HPLC method was investigated for the separation of citalopram and its four impurities by use of statistical experimental design. Initially, the influence of different experimental conditions (buffer pH, flow rate, and column temperature) on the chromatographic behavior of citalopram and its four impurities was investigated by use of partial least squares regression (PLSR) and multilayer perceptron (MLP) artificial neural networks (ANNs) trained by back-propagation. The developed models and the corresponding response surface plots were used to select the optimal HPLC conditions, buffer pH 7.0, flow rate 1.0 mL/ min, and column temperature 25 degrees C, for an efficient separation of citalopram and its four impurities. The elaborated HPLC method was found to be linear, specific, sensitive, precise, accurate, and robust. Retention times of citalopram and its impurities, obtained with the developed HPLC method, and the computed molecular parameters of the examined compounds were used in a quantitative structure retention relationship (QSRR) study. The PLSR and ANN algorithms were applied for the development of the QSRR methods. The MLP-two layers-ANN-QSRR model with root mean square error of prediction 0.105 and r(2) (observed versus predicted) 0.978 was selected. Since many different reaction conditions are applied for the synthesis of citalopram, different impurities and degradation products can be formed. Therefore, the developed QSRR model can be extended to the prediction of the retention times with the other citalopram impurities, degradation products, and metabolites.
... Stability-indicating HPTLC method has been developed for assay of (S)-CIT in presence of unknown degradation products formed through forced degradation studies (12), but it was out of scope because it did not separate and determine the impurities and has been established as non-chiral TLC-procedure (11,12). It is worth noting that only one TLC-method has been reported for separation of CIT (13). In this method only one enantiomer (S-CIT) was determined (13). ...
... It is worth noting that only one TLC-method has been reported for separation of CIT (13). In this method only one enantiomer (S-CIT) was determined (13). Moreover, none of the existing studies reported impurity details (11)(12)(13). ...
... In this method only one enantiomer (S-CIT) was determined (13). Moreover, none of the existing studies reported impurity details (11)(12)(13). ...
A novel economic procedure for the simultaneous stereospecific separation and analysis of (R)- and (S)-citalopram and its related substances or impurities has been developed and validated. Chromatography was performed on silica gel 60 F254 plates with acetonitrile: methanol: water (15:2.5:2.5: v/v/v) as a mobile phase containing 1.5 mM norvancomycin or 2.5 mM vancomycin as a selector at ambient temperature. (R)- and (S)-citalopram enantiomers in presence of its related substances; citalopram citadiol and citalopram N-oxide were well separated with significant Rf values of 0.33 ± 0.02, 0.85 ± 0.02, 0.45 ± 0.02 and 0.22 ± 0.02, respectively. The spots were detected with either iodine vapor, or by use of a UV lamp followed by densitometric measurement at 239 nm. All variables affecting the resolution, such as concentration of chiral selectors, mobile phase system at different temperatures and pH-values were investigated and the conditions were optimized. Calibration plots for analysis of (R)- and (S)-enantiomers were linear in the range of 0.2-16.8 μg/10 μl (R≥0.9994, n=6) with acceptable precision (%RSD<2.0) and accuracy (99.70 ± 0.85% and 99.51 ± 0.61% for (S)-citalopram and escitalopram, respectively). The limit of detection and quantification were 0.08 μg/10 μl and 0.25 μg/10 μl, respectively, for (R)- and (S)-citalopram. The proposed method is simple, selective, and robust and can be applied for quantitative determination of enantiomeric purity of (R)- and (S)-citalopram (escitalopram) as well as the related impurities in drug substances and pharmaceutical preparations. The method can be useful to investigate adulteration of pure isomer with the cheep racemic form.
... . Various publications available globally in the literature search for the determinations of Escitalopram by HPTLC [9], Capillary Electrophoresis [10], Colorimetric [11], HPLC and Spectrophotometric [12], Fluorometric and Thin Layer Chromatography Densitometry [13] and by LC/ESI-MS and NMR [14]. But all these publication and study were related to main analyte and its process/degradation impurities. ...
A simple and rapid high performance liquid chromatographic method has been established to quantify
the optically active precipitant Di-p-Toluoyl-d-Tartaric acid (DPTTA) at very low level in
Escitalopram oxalate drug substance. The method is subsequently validated to prove its suitability,
sensitivity and repeatability. The high performance liquid chromatographic (HPLC) method is
developed in such a way that to enhances the detection level and minimizes acquisition time by using
suitable buffer of 0.02% (v/v) of Orthophosphoric acid pH 3.0±0.5 and Acetonitrile as eluent in
isocratic mode. The retention time of DPTTA is about 4.0 min and the total acquisition time was less
than 15 min. The optimized method was validated to prove its performance characteristics by
demonstrating selectivity, sensitivity (limit of detection and quantification), linearity, precision and
accuracy. The experimentally established limit of detection and quantification was found to be 0.040
μg mL-1 and 0.120 μg mL-1 respectively and the overall percent accuracy (recovery) of the samples
evaluated at different concentration levels was found to be 99.0, indicating the sensitivity and accuracy
of this optimized HPLC method by citing the guideline requirement.
The objective of the present analysis was the improvement of easy, exact as well as reproducible and precise verifies reversed phase Liquid Chromatography with High Performance [UPLC] assays for Telmisartan and Ondansetron. The chromatographic splitting up was done on Acuity UPLC BEH C 18 (50×2.1mm and1.7µm) column with gradient elution. The injection amount was 1µl and also the detection was performed at 214 nm by utilizing photo diode array detector. The evolved as well as a validated UPLC way of Telmisartan and Ondansetron in tablet dosage styles based on ICH tips was precise and accurate, therefore it may be utilized for equally evaluation scientific studies of medications. This process demonstrated the repeatability of outcomes with regard to accuracy, scientific studies, robustness, and then program - suitability problems. Keywords: UPLC, Ondansetron, chromatography, Telmisartan, accuracy, robustness
