loratadine, Claritin
Capillary zone electrophoresis determination of loratadine in tablets.

Mikus P, Kubacak P, Valakova I, Havranek E.

Department of Pharmaceutical Analysis and Nuclear Pharmacy, Faculty of Pharmacy, Comenius University, Bratislava, Slovakia. mikus fpharm.uniba.sk

A capillary electrophoretic method was developed for the determination of loratadine in pharmaceutical formulations. Capillary zone electrophoresis (CZE) separation and UV absorbance photometric detection were carried out in a 160 mm capillary tube with a 300 microm internal diameter, hydrodynamically (membrane) closed. The influences of pH, carrier cation and counter ion on the migration parameters of loratadine were studied and the following conditions were selected: 24 mmol/l glycine as a carrier cation, 1.6 mmol/l citric acid and 84 mmol/l acetic acid as counter ions at pH 3.2, 100 microA and 25 degrees C. The proposed electrophoretic method was successfully validated. It was convenient for the sensitive, simple, rapid and highly reproducible assay of loratadine. The determination of loratadine in tablet forms was demonstrated as an application of the method. CZE analysis was completed within 6 min. The detection limit of loratadine was 1.96 micro/mol/l at a 240 nm detection wavelength and the relative standard deviation for its determination was 0.6% for migration time and 1.1% for peak area. CZE in a hydrodynamically closed separation system, used for the first time for the analysis of loratadine, should also be convenient for complex biological sample applications, as it is easily combinable online with the purification CE modes (e.g. ITP).

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15125568&dopt=Abstract loratadine, Claritin



loratadine, Claritin
Determination of loratadine in human plasma by HPLC with fluorescence detector and study on its bioavailability.

Xu XJ, Shang EX, Qiu FR, Mao GG, Xiang BR.

Center for Instrumental Analysis of China Pharmaceutical University, Nanjing 210009, China.

AIM: To establish an HPLC-fluorescence method for determination of loratadine in human plasma and evaluate its relative bioavailability. METHODS: An Alltech-C18 column and a mobile phase of acetonitrile-water-glacial acetic acid-triethylamine (90:100:6:0.15) were used. The fluorescence detector was set at Ex 274 nm, Em 450 nm. The flow rate was 1 mL.min-1. RESULTS: The calibration curve was linear over a concentration range of 0.2-30 micrograms.L-1. The limit of quantification was 0.2 microgram.L-1. The average method recoveries varied from 96% to 98%. The results showed AUC, Tmax, Cmax and T1/2 beta between the testing tablets, testing capsules and reference tablets had no significant difference (P > 0.05). Relative bioavailabilities were 107% +/- 17% and 100% +/- 14% respectively. CONCLUSION: The three formulations were bioequivalent.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15127620&dopt=Abstract loratadine, Claritin



loratadine, Claritin
Determination of donepezil hydrochloride (E2020) in plasma by liquid chromatography-mass spectrometry and its application to pharmacokinetic studies in healthy, young, Chinese subjects.

Lu Y, Wen H, Li W, Chi Y, Zhang Z.

Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 210009, People's Republic of China.

A sensitive, simple, and specific liquid chromatographic method coupled with electrospray ionization-mass spectrometry for the determination of donepezil in plasma is developed, and its pharmacokinetics in healthy, male, Chinese is studied. Using loratadine as the internal standard, after extraction of the alkalized plasma by isopropyl alcohol-n-hexane (3:97, v/v), solutes are separated on a C(18) column with a mobile phase of methanol-acetate buffer (pH 4.0) (80:20, v/v). Detection is performed with a time-of-flight mass spectrometer equipped with an electrospray ionization source operated in the positive-ionization mode. Quantitation of E2020 is accomplished by computing the peak area ratio (donepezil [M+H](+) m/z 380-loratadine [M+H](+) m/z 383) and comparing them with the calibration curve (r = 0.9998). The linear calibration curve is obtained in the concentration range 0.1-15 ng/mL. The limit of quantitation is 0.1 ng/mL. The mean recovery of E2020 from human plasma is 99.4% +/- 6.3% (ranging 93.4-102.6%). The inter- and intraday relative standard deviation is less than 15%. After an oral administration of 5 mg E2020 to 20 healthy Chinese volunteers, the main pharmacokinetic parameters of E2020 are as follow: T(max), 3.10 +/- 0.55 h; t((1/2)), 65.7 +/- 12.8 h; C(max), 10.1 +/- 2.02 ng/mL; MRT, 89.4 +/- 13.4 h; and CL/F, 9.9 +/- 4.3 L/h.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15189594&dopt=Abstract loratadine, Claritin



loratadine, Claritin
Oral administration of desloratadine prior to sensitization prevents allergen-induced airway inflammation and hyper-reactivity in mice.

Blumchen K, Gerhold K, Thorade I, Seib C, Wahn U, Hamelmann E.

Department of Pediatric Pneumology and Immunology, University Hospital Charite, Berlin, Germany.

BACKGROUND: Histamine-1-receptor (H1R)-antagonists were shown to influence various immunological functions on different cell types and may thus be employed for immune-modulating strategies for the prevention of primary immune responses. OBJECTIVE: The aim of this study was to investigate the effects of an H1R-antagonist on allergen-induced sensitization, airway inflammation (AI) and airway hyper-reactivity (AHR) in a murine model. METHODS: BALB/c mice were systemically sensitized with ovalbumin (OVA) (six times, days 1-14) and challenged with aerosolized allergen (days 28-30). One day prior to the first and 2 h prior to every following sensitization, mice received either 1 or 0.01 microg of desloratadine (DL) or placebo per os. RESULTS: Sensitization with OVA significantly increased specific and total IgE and IgG1 serum levels, as well as in vitro IL-5 and IL-4 production by spleen and peribronchial lymph node (PBLN) cells. Sensitized and challenged mice showed a marked eosinophilic infiltration in broncho-alveolar lavage fluids and lung tissues, and developed in vivo AHR to inhaled methacholine. Oral treatment with DL prior to OVA sensitization significantly decreased production of OVA-specific IgG1, as well as in vitro Th2-cytokine production by spleen and PBLN cells, compared with OVA-sensitized mice. Moreover, eosinophilic inflammation and development of in vivo AHR were significantly reduced in DL-treated mice, compared with sensitized controls. CONCLUSION: Treatment with H1R-anatagonist prior to and during sensitization suppressed allergen-induced Th2 responses, as well as development of eosinophilic AI and AHR. This underscores an important immune modulating function of histamine, and implies a potential role of H1R-anatagonists in preventive strategies against allergic diseases.

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loratadine, Claritin
Does hormone therapy increase allergic reactions and upper gastrointestinal problems? Results from a population-based study of Swedish woman. The women's health in the Lund area (WHILA) study.

Khatibi E A, Samsioe G, Li C, Lidfeldbt J, Agardh CD, Nerbrand C; Women's health in the Lund area study.

Department of Obstetrics and Gynaecology, Lund University Hospital, Lund S-221 85, Sweden.

OBJECTIVES: To delineate the use of various drugs particularly pertaining to allergy and upper gastrointestinal problems in relation to hormone status in middle aged women. METHODS: An analysis from a population-based study on women born between 1935 and 1945 and lived in the Lund area southern Sweden. Of 10,766 women, 6,917 provided complete data sets; in turn 5,673 were assessed for the use of medication in this study. Among the cohort, 9% of women were premenopausal (PM), 54% were postmenopausal without hormone replacement therapy (PM0) and 37% were current hormone replacement therapy users (PMT). RESULTS: There were 7 (1.3%) women in PM, 11 (0.4%) in PM0 and 21 (1.0%) in PMT group who used loratadine regularly. There was a significant difference between the PM and PM0 groups and also between the PM0 and PMT groups in the use of loratadine (P < 0.05 ). Among 21 loratadine users in PMT group 4 (19%) used transdermal patches and 17 (81%) used oral HRT. The result for omeprazole use was as follows: 4 (0.8%) of PM group, 39 (1.3%) of PM0 group and 42 (2.0%) of PMT group. The use of omeprazole was significantly higher in the PMT group than in the PM (P = 0.05 ) and PM0 group (P < 0.05 ). There was no relation between the use of omeprazole and smoking or alcohol consumption. CONCLUSIONS: Use of hormone replacement therapy seems to be related to a higher frequency of omeprazole and loratadine use, which implies that hormone replacement therapy, may be associated with more upper gastrointestinal symptoms as well as allergy.

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loratadine, Claritin
Rapid determination of loratadine in small volume plasma samples by high-performance liquid chromatography with fluorescence detection.

Amini H, Ahmadiani A.

Department of Pharmacology, Neuroscience Research Center, Shaheed Beheshti University of Medical Sciences, P.O. Box 19835-355, Tehran, Iran.

A simple and rapid high-performance liquid chromatographic method with fluorescence detection was developed for the determination of loratadine in small volume plasma samples. Liquid-liquid extraction of loratadine and diazepam (as internal standard) from plasma samples was performed with n-butyl alcohol/n-hexane (2:98, v/v) in alkaline condition followed by back-extraction into diluted perchloric acid. Chromatography was carried out using a C8 column (250 x 4.6 mm, 5 microm) under isocratic elution with acetonitrile-20 mM sodium dihydrogen phosphate-triethylamine (43:57:0.02, v/v), pH 2.4. Analyses were run at a flow-rate of 1.0 ml/min at room temperature. The method was specific and sensitive with a quantitation limit of 0.62 ng/ml and a detection limit of 0.2 ng/ml at a signal-to-noise ratio of 3:1. The mean absolute recovery of loratadine from plasma was 84%, while the intra-and inter-day coefficient of variation and percent error values of the assay method were all less than 9.7%. Linearity was assessed in the range of 0.62-20 ng/ml in plasma with a correlation coefficient of greater than 0.999. The method has been used to analyze several hundred human plasma samples for bioavailability studies. Copyright 2004 Elsevier B.V.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15315769&dopt=Abstract loratadine, Claritin