1.Effects of Prednisolone on the Pharmacokinetics of Loratadine after Oral and Intravenous Administration of Loratadine in Rats
Cheng Li, Minhee Kim, and Jun-Shik Choi. Arch Pharm Res Vol 33, No 9, 1395-1400, 2010
Loratadine undergoes extensive first-pass metabolism in the liver to form its major metabolite desloratadine, which also possesses antihistamine activity and is subject to further metabolism (Hilbert et al., 1987; Kreutner et al., 2000; Henz, 2001). CYP3A4 and CYP2D6 enzymes are responsible for the metabolism of loratadine to desloratadine (Yumibe et al., 1996). Loratadine is also a substrate of P-glycoprotein (P-gp) (Bradley et al., 1987). Since P-gp is co-localized with CYP3A4 in the small intestine, P-gp and CYP3A4 may act synergistically in absorption and first-pass metabolism of drugs, respectively (Pichard et al., 1990; Wacher et al., 1998; Ito et al., 1999).
2.Physicochemical characterization and dissolution enhancement of loratadine by solid dispersion technique
Suresh Bandari, Subash Jadav, Basanth Babu Eedara. Korean J. Chem. Eng., 30(1), 238-244 (2013)
In-vitro dissolution studies of pure loratadine, physical mixture, solid dispersions and tablets were done by using USP XXIV type II apparatus (Electrolab, Mumbai, India). Samples equivalent to 10 mg of loratadine were added to the 900 ml distilled water containing 0.1% w/v sodium lauryl sulfate at 37±0.5 ℃ and stirred at 50 rpm. An aliquot of 5 ml was withdrawn at predetermined time intervals and filtered through 0.45 μm filter using a syringe filter. The withdrawn volume was replenished immediately with the same volume of fresh dissolution medium in order to keep the total volume constant. The filtered samples were diluted suitably and assayed for loratadine content with a UV spectrophotometer at 280 nm. The mean of at least three determinations was used to calculate the drug release.
3.Plasma histamine levels (H) during adjunctive H1-receptor antagonist treatment with loratadine in patients with active Inflammatory Bowel disease (IBD)
M. Raithel • A. Nagel • Y. Zopf • Th. deRossi, Inflamm. Res. (2010) 59 (Suppl 2):S257–S258
The cumulative decrease of histamine values during the trial with or without loratadine was 0.30 and 0.13 ng histamine/ml 9 m2 BSA in Crohn’s disease (n.s.). Plasma histamine values in loratadine treated and untreated patients with ulcerative colitis decreased by 0.03 and 0.20 ng histamine/ml 9 m2 BSA (n.s.). Loratadine tended to decrease plasma histamine values more efficiently in Crohn’s disease than in ulcerative colitis. However, the dosage used was very low as originally described for allergic rhinoconjunctivitis. Considering the greater mucosal surface area in the gastrointestinal tract; future trials should consider higher doses to adequately block all intestinal H1-receptors and produce significant reductions in plasma histamine levels in IBD.