Efficacy assessment of an intramammary treatment with a new recrystallized enrofloxacin vs ceftiofur and parenteral enrofloxacin in dairy cows with nonsevere clinical mastitis.

A recrystallized form of enrofloxacin as dehydrate-HCl (enro-C) was assessed for bacteriological and clinical cure efficacies in Holstein-Friesian cows affected of nonsevere clinical mastitis. Treatments were enro-Csusp (n = 81), treated with a pharmaceutical suspension of enro-C/quarter; group enro-Cpd (n = 80) treated as above, but using enro-C powder suspended in water; group CF (n = 65), treated with ceftiofur HCl/quarter; and group enroR (n = 66), treated with standard enrofloxacin solution (5 mg/kg, intramuscular). Cows had a mean milk production of 31 L/day and were 2-3 lactational periods old. Treatments were administered every 24 hr for 3 days. Groups treated with enro-C exhibited statistically significant (p > .05) better clinical cure as compared to groups treated with CF or enroR (95.06%, 96.25%, 67.79%, and 57.55%, for enro-Csusp , enro-Cpd , CF, and enroR , respectively). In contrast, probability of bacteriological cure was not statistically different among treatments. Yet, the outstanding clinical and bacteriological cure rates obtained for enro-C for nonsevere cases of mastitis is superior to previously reported data for parenteral enrofloxacin and other antibacterial-intramammary treatments. Impact of using enro-C on the rate and pattern of bacterial resistance, somatic cell counts and milk electric conductivity, must be studied. Also, the use of enro-C for complicated cases of mastitis should be studied and milk withdrawal times must be accurately established.

Physicochemical characterization and pharmacokinetics in broiler chickens of a new recrystallized enrofloxacin hydrochloride dihydrate.

Enrofloxacin, a key antimicrobial agent in commercial avian medicine, has limited bioavailability (60%). This prompted its chemical manipulation to yield a new solvate-recrystallized enrofloxacin hydrochloride dihydrate entity (enroC ). Its chemical structure was characterized by means of mass spectroscopy, Fourier transformed infrared spectroscopy, X-ray powder diffraction, and thermal analysis. Comparative oral pharmacokinetics (PK) of reference enrofloxacin (enroR ) and enroC in broiler chickens after oral administration revealed noticeable improvements in key parameters and PK/PD ratios. Maximum serum concentration values were 2.61 ± 0.21 and 5.9 ± 0.42 µg/mL for enroR and enroC , respectively; mean residence time was increased from 5.50 ± 0.26 h to 6.20 ± 0.71 h and the relative bioavailability of enroC was 336%. Considering Cmax /MIC and AUC/MIC ratios and the MIC values for a wild-type Escherichia coli O78/H12 (0.25 µg/mL), optimal ratios will only be achieved by enroC (Cmax /MIC = 23.6 and AUC/MIC = 197.7 for enroC ; vs. Cmax /MIC = 10.4 and AUC/MIC = 78.1 for enroR ). Furthermore, enroC may provide in most cases mutant prevention concentrations (Cmax /MIC ≥ 16). Ready solubility of powder enroC in drinking water at concentrations regularly used (0.01%) to provide an additional advantage of enroC in the field. Further development of enroC is warranted before it can be recommended for clinical use in veterinary medicine.

Characterization of physical interaction between Casiopeina III-ia and chitosan. Toward a Cas III-ia drug delivery system.

Casiopeínas are a new generation of anticancer drugs that have shown great in vitro and in vivo antineoplastic activities. Information about interaction drug-excipient, for developing a based-nanoparticle drug delivery system, has not been investigated yet. In order to elucidate if chitosan (CS) modifies the copper complex due to its interaction with Cu(2+) ion, different studies in aqueous media between CS and Casiopeina III-ia (Cas III-ia) were carried out. CS-Cas III-ia mixtures were characterized by viscosity curves, UV-vis, EPR, and in vivo activity against HeLa cell line. Rheological behavior showed a decrease of viscosity when the drug was present due to diminished electrostatic interactions of charged amine group. UV-vis results illustrate that Cas III-ia is not stable at low pH as a result of interaction with acetic acid. However, when chitosan is present at the acidic solution Cas III-ia is stable. These results are supported by EPR studies. Finally, activity of the drug against HeLa cell line was not modified. Therefore, the present work presents evidence that there is no breaking of copper complex due to interaction between CS and Cas III-ia in acidic media. In addition, Cas III-ia maintains both its stability and effectiveness against cancer cell line.