Analytical Sciences

Abstract − Analytical Sciences, 21(4), 391 (2005).

Retentivity and Enantioselectivity of Uniformly-sized Molecularly Imprinted Polymers for (S)-Nilvadipine in Aqueous and Non-Aqueous Mobile Phases
Haruyo SAMBE,*,** Kaori HOSHINA,** and Jun HAGINAKA**
*Laboratory of Intellectual Fundamentals for Environmental Studies, National Institute for Environmental Studies, 16-2, Onogawa, Tukuba, Ibaraki 305-8506, Japan
**Faculty of Pharmaceutical Sciences, Mukogawa Women’s University, 11-68, Koshien Kyuban-cho, Nishinomiya, Hyogo 663-8179, Japan
Uniformly-sized molecularly imprinted polymers (MIPs) for (S)-nilvadipine have been prepared by a multi-step swelling and polymerization method using methacrylic acid or 4-vinylpyridine (4-VPY) as a functional monomer, ethylene glycol dimethacrylate (EDMA) as a cross-linker, and toluene, chloroform, cyclohexanol or phenylacetonitrile as a porogen. The chiral recognition abilities of the MIPs for nilvadipine were evaluated using aqueous and non-aqueous mobile phases. Among the MIPs, the (S)-nilvadipine-imprinted 4-VPY-co-EDMA polymers prepared using toluene as a porogen showed the highest recognition ability for nilvadipine in both aqueous and non-aqueous mobile phases. In addition to molecular shape recognition, hydrogen-bonding interactions of the NH proton of nilvadipine with a pyridyl group of the (S)-nilvadipine-imprinted 4-VPY-co-EDMA polymers could play an important role in the retention and chiral recognition of nilvadipine in aqueous and non-aqueous mobile phases. Furthermore, the MIP for (S)-nilvadipine gave the highest molecular recognition ability when a porogenic solvent during polymerization was used as the mobile phase modifier.