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 incorporative 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 process. The diameter of NP increased when the initial drug concentration was higher than 1.2 mg/ml. Ciproflaxacin content of NP was influenced by the drug concentration in the polymerization and incubation media. The binding capacity in the adsorptive process was not influenced by the pH. In contrast, the entrapment of ciprofloxacin in the NP by incorporation was greatly influenced by the pH in the range 1.5-4. Thin layer chromatography (TLC) of NP prepared by incorporation showed new products suggesting interactions between ciprofloxacin and isobutylcyanoacrylate. Ciprofloxacin release from nanoparticles prepared by the incorporating process was found to be slower as compared to nanoparticles produced by adsorptive process from which the drug release was practically 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.