| Title | Development of a pH-responsive drug delivery system for enantioselective-controlled delivery of racemic drugs. | | Author(s) | Suedee R, Jantarat C, Lindner W, Viernstein H, Songkro S, Srichana T | | Institution | Molecular Recognition Materials Research Unit, Drug Delivery System Excellence Center and Department of Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hatyai, Songkla 90112, Thailand. | | Source | J Control Release 2009 Oct 23. | | Abstract | This study aimed to develop enantioselective-controlled drug delivery systems for selective release of the required (S)-enantiomer in a dose formulation containing a racemic drug in response to pH stimuli. The recognition system was obtained from a nanoparticle-on-microsphere (NOM) molecularly imprinted polymer (MIP) with a multifunctional chiral cinchona anchor synthesised by suspension polymerisation using ethylene glycol dimethacrylate as a cross-linker. (S)-omeprazole was used as an imprinting molecule conferring stereoselectivity upon the polymers. The ability of the prepared recognition polymers to selectively rebind (S)-omeprazole was evident at different pH levels (the highest being at pH 7.4). The partial selective-release phenomenon of the (S)-enantiomer in MIP-containing composite cellulose membranes with increased vehicular racemic omeprazole concentrations was highly pH-dependent. Cinchona-bonded polymers imprinted with (S)-omeprazole could recognise the moldable contact site of (S)-omeprazole independently of its chirality; this is responsible for the delivery of (S)-enantiomer from racemic omeprazole. The controlled-release drug devices were fabricated with synthesised composite latex, and consisted of a pH-stimuli-responsive poly(hydroxyethyl methacrylate) (HEMA) and polycaprolactone-triol (PCL-T) blend, and a MIP with preloaded drug, along with pH 7.4 buffer in the device's interior. The results demonstrate that drug delivery systems containing (S)-omeprazole imprinted cinchona-polymer nanoparticle-on-microspheres may maximise efficacy while minimising dose frequency. | | Language | ENG | | Pub Type(s) | JOURNAL ARTICLE
| | PubMed ID | 19857533 |
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