1.Photodegradation and photostability-indication of mequitazine.
Abdel-Moety EM1, Ibrahim MA, Rezk MR. Spectrochim Acta A Mol Biomol Spectrosc. 2009 Oct 15;74(3):740-5. doi: 10.1016/j.saa.2009.08.006. Epub 2009 Aug 12.
The photochemical behavior is investigated for mequitazine (MQ) illustrating possible mechanisms and photodegradation products formed. Accelerated photolysis is done for MQ under justified stress conditions by subjecting aqueous drug solutions to radiation for specified period of time. Synthesis of the main photodegradants, the sulfoxide, is achieved. Selective quantification of MQ, singly in bulk form, pharmaceutical formulations and/or in the presence of its photodegradants is demonstrated. The indication of stability has been undertaken under conditions likely to be expected at normal storage conditions using a simple colorimetric method based on oxidation of the intact phenothiazine drug by potassium iodate in acid medium to form a red colored product adequate for quantitative estimation of the studied drug.
2.Expedient synthesis of mequitazine an antihistaminic drug by palladium catalyzed allylic alkylation of sodium phenothiazinate.
Gonnot V1, Nicolas M, Mioskowski C, Baati R. Chem Pharm Bull (Tokyo). 2009 Nov;57(11):1300-2.
A short and straightforward synthesis of the antihistaminic drug mequitazine is reported, based on an efficient palladium catalyzed allylic alkylation of 1-aza-bicyclo[2.2.2]oct-2-en-3-ylmethyl acetate using sodium phenothiazinate in mild conditions.
3.Asymmetric synthesis of (+)-mequitazine from quinine.
Leroux S1, Larquetoux L, Nicolas M, Doris E. Org Lett. 2011 Jul 1;13(13):3549-51. doi: 10.1021/ol2012567. Epub 2011 Jun 9.
The first asymmetric synthesis of the antihistaminic drug mequitazine is reported. Our approach started from quinine, a Cinchona alkaloid, whose chiral information was exploited for setting up the stereogenic center of (+)-mequitazine.
4.Central nervous system effects of the second-generation antihistamines marketed in Japan--review of inter-drug differences using the proportional impairment ratio (PIR)-.
Isomura T1, Kono T2, Hindmarch I3, Kikuchi N4, Murakami A4, Inuzuka K4, Kawana S5. PLoS One. 2014 Dec 12;9(12):e114336. doi: 10.1371/journal.pone.0114336. eCollection 2014.
BACKGROUND: Second-generation antihistamines (AHs) have, in general, fewer sedative effects than the first-generation. However, important inter-drug differences remain in the degree of cognitive and/or psychomotor impairment. The extent to which a particular compound causes disruption can be conveniently compared, to all other AHs, using the Proportional Impairment Ratio (PIR). Although the PIR can differentiate the relative impairment caused by individual drugs, there is no indication of the reliability of the ratios obtained.