History and formulations
Levocetirizine was first launched in 2001 by Belgian pharmaceutical company UCB. It is sold under the brand name Xyzal// in Australia, Czech Republic, Austria, Finland, France, Ireland, Netherlands, Portugal, Romania, Taiwan, Turkey, United States, South Africa and UK; Xuzal in Mexico; Xusal in Germany; and Xozal in Greece. In Hungary it is marketed by Richter Gedeon under the Zilola brand name.
levocetirizine is called a non-sedating antihistamine as it does not enter the brain in significant amounts, and is therefore unlikely to cause drowsiness. However, some people may experience some slight sleepiness, headache, mouth dryness,lightheadedness, vision problems (mainly blurred vision), palpitations and fatigue.
latest research shows levocetirizine reduces asthma attacks by 70% in children.
- Grant, JA; Riethuisen, JM; Moulaert, B; DeVos, C; Gamalero, C.; Descalzi, D.; Folli, C.; Passalacqua, G. et al. (2002-02). "A double-blind, randomized, single-dose, crossover comparison of levocetirizine with ebastine, fexofenadine, loratadine, mizolastine, and placebo: suppression of histamine-induced wheal-and-flare response during 24 hours in healthy male subjects.". Ann Allergy Asthma Immunol 88 (2): 190–197. doi:10.1016/S1081-1206(10)61995-3. PMID 11868924.
- XOZAL technical specifications booklet.
- Pasquali, M; Baiardini, I; Rogkakou, A; Riccio, AM; Gamalero, C; Descalzi, D; Folli, C; Passalacqua, G et al. (2006-09)."Levocetirizine in persistent allergic rhinitis and asthma: effects on symptoms, quality of life and inflammatory parameters.".Clinical & Experimental Allergy 36 (9): 1161–7. doi:10.1111/j.1365-2222.2006.02548.x. PMID 16961716.
Figure 2 displays the synthesis of Cetirizine (Zyrtec). Levocetirizine, the R-enantiomer of cetirizine, is then formed from pyroglutamate salts in a synthesis that does not have attainable details.
The synthesis of Cetrizine begins by reducing molecule 33 with a catecholborane. This reaction yields molecule 34, which is then treated with tetraflouroboric acid and reacted with an amine, compound 35. In order to remove the chromium group, the compound is refluxed in pyridine and undergoes an acid hydrolysis. This results in a yield of cetrizine.
Identification of all chirality centers:
Stereogenic centers are carbon atoms that are bonded to 4 groups. Tetrahedral stereogenic centers are stereogenic centers that are not only bonded to 4 groups but are more importantly bonded to 4 different groups. If a molecule contains 1 tetrahedral stereogenic center it is said to be chiral (nonsuperimposable on its mirror image).If a given compound contains more than 1 stereogenic center it must be further analyzed to determine if it is chiral or achiral(superimosable on its mirror image). The carbon atom bonded to the phenyl groups was found to be a tetrahedral stereogenic center. Therefore,xyzal,which was found to contain only 1 tetrahedral stereogenic center is generally considered a chiral compound because it meets the requirements of chirality and does not have a plane of symmetry that superimposes one half of the molecule on the other and is not super imposable on its mirror image.
Spectral data for Xyzal (IR and NMR):