CIPROFLEXACIN-LOADED POLYISOBUTYLCYANOACRYLATE NANOPARTICLES - PREPARATION AND CHARACTERIZATION

Experimental conditions for attachment of ciprofloxacin hydrochloride to poly(isobutylcyanoacrylate) (PIBCA) nanoparticles (NP) and release of drug were studied. Attachment of the drug was performed by the inco rporative and adsorptive processes. The pH, and to a lesser degree the drug concentration in the reaction medium, were shown to be important factors in controlling the size of NP only in the incorporative proce ss. The diameter of NP increased when the initial drug concentration w as higher than 1.2 mg/ml. Ciproflaxacin content of NP was influenced b y the drug concentration in the polymerization and incubation media. T he binding capacity in the adsorptive process was not influenced by th e pH. In contrast, the entrapment of ciprofloxacin in the NP by incorp oration was greatly influenced by the pH in the range 1.5-4. Thin laye r chromatography (TLC) of NP prepared by incorporation showed new prod ucts suggesting interactions between ciprofloxacin and isobutylcyanoac rylate. Ciprofloxacin release from nanoparticles prepared by the incor porating process was found to be slower as compared to nanoparticles p roduced by adsorptive process from which the drug release was practica lly complete within 1 h in absence of esterases in the release medium. Drug release from the two types of NP was accelerated in the presence of esterases in the release medium. (C) 1997 Elsevier Science B.V.