Enantioselective analysis of oxybutynin and N-desethyloxybutynin with application to an in vitro biotransformation study - Fonseca, Patrícia da; Freitas, Luis Alexandre Pedro de; Pinto, Luis Felipe Ribeiro; Pestana, Cezar Rangel; Bonato, Pierina Sueli (Journal of Chromatography B, 2008)