In vitro and in vivo investigation of dexibuprofen derivatives for CNS delivery.
OBJECTIVE
Dexibuprofen, the S(+)-isomer of ibuprofen, is an effective therapeutic agent for the treatment of neurodegenerative disorders. However, its clinical use is hampered by a limited brain distribution. The aim of this study was to design and synthesize brain-targeting dexibuprofen prodrugs and to evaluate their brain-targeting efficiency using biodistribution and pharmacokinetic analysis.


METHODS
In vitro stability, biodistribution and pharmacokinetic studies were performed on male Sprague-Dawley rats. The concentrations of dexibuprofen in biosamples, including the plasma, brain, heart, liver, spleen, lung, and kidney, were measured using high pressure lipid chromatography (HPLC). The pharmacokinetic parameters of the drug in the plasma and tissues were calculated using obtained data and statistics.


RESULTS
Five dexibuprofen prodrugs that were modified to contain ethanolamine-related structures were designed and synthesized. Their chemical structures were confirmed using (1)H NMR, (13)C NMR, IR, and HRMS. In the biodistribution study, 10 min after intravenous administration of dexibuprofen (11.70 mg/kg) and its prodrugs (the dose of each compound was equivalent to 11.70 mg/kg of dexibuprofen) in male Sprague-Dawley rats, the dexibuprofen concentrations in the brain and plasma were measured. The C(brain)/C(plasma) ratios of prodrugs 1, 2, 3, 4, and 5 were 17.0-, 15.7-, 7.88-, 9.31-, and 3.42-fold higher than that of dexibuprofen, respectively (P<0.01). Thus, each of the prodrugs exhibited a significantly enhanced brain distribution when compared with dexibuprofen. In the pharmacokinetic study, prodrug 1 exhibited a brain-targeting index of 11.19 {DTI=(AUC(brain)/AUC(plasma))(1)/(AUC(brain)/AUC(plasma))(dexibuprofen)}.


CONCLUSIONS
The ethanolamine-related structures may play an important role in transport across the brain blood barrier.
Key Laboratory of Drug Targeting and Drug Delivery Systems, West China School of Pharmacy, Sichuan University, Chengdu, China.
Xuan
X
Zhang
Xing
X
Liu
Tao
T
Gong
Xun
X
Sun
Zhi-rong
ZR
Zhang
D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D004355:Drug Stability; D007052:Ibuprofen / Q000031:analogs & derivatives* / Q000737:chemistry / Q000493:pharmacokinetics; D008297:Male; D011355:Prodrugs / Q000737:chemistry* / Q000493:pharmacokinetics*; D051381:Rats; D017207:Rats, Sprague-Dawley
D011355:Prodrugs; C539402:dexibuprofen; D007052:Ibuprofen