The inclusion behavior of natural cyclodextrins (CDs) and polymers based on natural cyclodextrins (CD-polymer), in solution and in solid-state, was studied towards a poorly water-soluble anti-helminthic drug, albendazole (ABZ), chemically methyl[5-(propylthio)-1-H-benzimidazol-2yl]carbamate. Drug-cyclodextrin solid systems were prepared by freeze-drying. Phase solubility study was used to evaluate the interaction in solution, between ABZ/(CDs) and ABZ/CD-polymers. The stability constants of ABZ/natural CDs and ABZ/CD-polymers complexes were calculated by phase solubility method. The apparent solubility of Albendazole was enhanced especially with poly alpha-CD. The formation of inclusion complexes with natural CDs and polymers of cyclodextrin in the solid-state form were confirmed by Fourier Fransform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC) and proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR).

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Composite lms consisting of Fe hydroxide, Ni hydroxide and polyethylenimine (PEI) were obtained by the combined electrolytic -electrophoretic deposition method. The proposed method for PEI charging and deposition is based on the use of cationic polymer -metal ion complexes. Cathodic deposits were obtained on Pt and Ag substrates. By varying both the concentration of PEI in solutions and the deposition time, the amount of material deposited and its composition can be varied. The method was used to fabricate NiFe 2 O 4 lms. The deposits were studied by thermogravimetric analysis, X-ray diffraction analysis and SEM. The mechanism of electrochemical intercalation of PEI into hydroxide deposits is discussed. SE/S268The authors are in the

Cryptosporidiosis, the leading cause of endemic and epidemic diarrhoeal disease worldwide is due to Cryptosporidium parvum, a spore-forming protozoan. Anticryptosporidial pharmacological and/or immunological agents were initially tested in immunodeficient models of cryptosporidiosis, and sinefungin exhibited a significant dose dependent curative and preventive activity. Shedding relapses observed after discontinuation of sinefungin therapy lead to identify the bile ducts as a protected reservoir that may sustain chronic infection. The MIC50 of the sinefungin observed in vitro studies is 14.5 microg/ml. It is a hydrophilic drug lowly absorbed when orally administered and nephrotoxic after IV injection. To avoid this toxic effect, Neal's team prepared sinefungin loaded microspheres and proved that encapsulated sinefungin was 10 times more effective than free sinefungin. This optimistic result led us to study the nanoparticles as drug carrier for sinefungin. In this study, we prepared optimal sinefungin loaded PLGA nanoparticles. Physico-chemical characterization, in vitro drug release and in vivo studies were assessed. Negative surface-charged (-56.1 mV) sinefungin loaded PLGA nanoparticles were prepared with a homogenous size of 200 nm. Optimal formulation led to a drug content of 9.18% w/w (4.59 mg) and a drug entrapment of 15.16%. Dilution technique was used to study the release of sinefungin in vitro. 93.03% of sinefungin were released from dilution 1:5 to 1:20. This burst effect could probably due to the adsorption of the drug on the surface of the nanoparticles. A second step with a lower release was observed from dilution 1:20 to 1:100 which may correspond to the diffusion out of the drug solution from the nanoparticles into the bulk release medium. Investigations in rats showed that only 1.23 mg of sinefungin loaded in PLGA nanoparticles led to a decrease of sinefungin in the urine (0.23 mg vs. 4.27 mg for IV administration of free sinefungin) and to an increase of sinefungin concentration in the bile (6.63 microg/ml vs. 3.89 microg/ml for IV administration of free sinefungin). But the biliary concentration of encapsulated sinefungin (6.63 microg/ml) is still nearly 2 times lower than the MIC50.

The object of this work is to investigate physicochemical characteristics and inclusion behavior of binary systems based on cyclodextrin polymer (Poly-CD) or native cyclodextrins (CDs) with a poorly water-soluble, nonsteroidal anti-inflammatory drug, nimesulide (NIM) chemically, N-(4-nitro-2-phenoxyphenyl)methanesulfonamide. Our formulations were studied in solution and solid-state. Drug-cyclodextrin solid binary systems were prepared by the freezedrying method. Phase solubility study was used to evaluate the interaction in solution, between NIM/CDs and NIM/(Poly-CD). The stability constants of NIM/CDs and NIM/(Poly-CD) complexes were calculated using the phase solubility method. The apparent solubility of NIM was enhanced especially with Poly--CD (up to78-fold) in neutral aqueous solutions without any organic solvents or surfactants. Copmlexes formation was confirmed, in the solid state, by differential scanning calorimetry, infrared spectroscopy and DRX. Complexation spontaneity of drug with cyclodextrin polymers was highlighted using G° values.