POLYMERIC MOLLUSCICIDE FOR CONTROLLED-RELEASE OF BAYLUSCIDE

Polymeric molluscicides containing a niclosamide moiety have been prep ared by the chemical reactions of the commercial Polymers poly(chlorom ethylstyrene) (2% DVB) and Amberlite IR-120 (8% DVB) with Bayluscide. The resulting polymers contain the Bayluscide active group either via a covalent bond or through physical interaction with the diethanolamin e groups of the modified polymers. The release rates of niclosamide we re determined in different pH media by UV spectrophotometric analyses. The hydrolysis data showed that the release rates are strongly depend ent upon the pH of the medium, and the structure and composition of th e polymers. The linkage between the polymer and the niclosamide moiety , i.e. the relative effects of covalent bonding against physical inter action of the molluscicide to a polymer substrate, also appeared to be an important factor affecting the rates of release as demonstrated by the resulting differences in the release rates from the different pol ymeric systems.