Addition of grape pomace flour in the diet on laying hens in heat stress: Impacts on health and performance as well as the fatty acid profile and total antioxidant capacity in the egg.

The aim of this study was to evaluate whether the addition of grape pomace flour (GPF) in the diet of laying hens at the end of the productive cycle and on heat stress could exert benefits on their health and performance, as well as egg quality. For this, 74-week-old laying hens (n = 64) were divided into four groups with four repetitions each, as follow: T0 (the control group; without GPF), T1 (1% GPF), T2 (2% GPF) and T3 (3% GPF) during 35 days. Percentage of laid eggs was higher in the group T1 compared to T0, and the feed intake was higher in the groups T1, T2 and T3 compared to T0. There was no difference regarding the chemical-physical composition of fresh eggs; however, eggs from GPF-fed chickens showed changes after storage regarding specific gravity, yolk index, pH of yolk, albumen and Haugh unit compared to T0. Fresh or stored egg yolk from GPF groups showed higher antioxidant capacity and lower lipid peroxidation compared to T0. GPF (3%) prevented the reduction of monounsaturated fatty acids in the yolk of stored eggs compared to T0. Glutathione peroxidase and superoxide dismutase activities, as well as total antioxidant capacity against peroxyl radicals were higher in the serum of laying hens that received GPF compared to T0, while lipid peroxidation was lower. In summary, the addition of GPF in the diet for laying hens at the end of the productive cycle can be beneficial for animal health and exerted positive effects in their performance and egg quality.

Development and validation of a microbiological agar assay for determination of cefuroxime sodium in pharmaceutical preparations.

Cefuroxime (CFU) is a semi-synthetic cephalosporin with a relatively broad-spectrum antimicrobial activity, and belongs to the second generation of cephalosporins. Regarding the quality control of medicines, a validated microbiological assay for determination of cefuroxime sodium in pharmaceutical formulations has not been reported yet. With this purpose, this paper reports the development and validation of a simple, sensitive, accurate and reproducible agar diffusion method to quantify CFU sodium in injectable formulations. The assay is based on the inhibitory effect of CFU upon the strain of Staphylococcus aureus ATCC 6538P used as test microorganism. The results were treated statistically by analysis of variance and were found to be linear (r=0.9998) in the selected range of 8.0-32.0 microg/ml; precise [repeatability: relative standard deviation (RSD)=1.56%; intermediate precision: between-day RSD=1.27%; between analyst RSD=1.13%] and accurate (101.58%). The bioassay specificity was studied by evaluation of degraded sample at 50 degrees C with analysis at 0, 24 and 48 h in parallel with the pharmacopeial liquid chromatography method for CFU. The results demonstrated the validity of the proposed bioassay, which allows reliable quantitation of CFU sodium in pharmaceutical samples and therefore can be used as a useful alternative methodology for the routine quality control of this medicine.

Development and validation of an agar diffusion assay for determination of ceftazidime in pharmaceutical preparations.

Ceftazidime (CFZ) is a broad spectrum parenteral beta-lactam antibiotic of the cephalosporin family. This paper reports the development and validation of an agar diffusion microbiological assay using the cylinder-plate method for determination of CFZ in powder for injection. The validation carried out yielded good results in terms of linearity, precision, accuracy, selectivity, and robustness. The assay is based on the inhibitory effect of CFZ upon the strain of Pseudomonas aeruginosa ATCC 27853 used as the test microorganism. The results of the assays were treated statistically by analysis of variance and were found to be linear (correlation coefficient = 0.999998) in the selected range of 8.0-32.0 microg/mL; precise [repeatability: relative standard deviation (RSD) = 1.11%; intermediate precision: between-day RSD = 1.37% and between-analyst RSD = 1.41%]; and accurate. The selectivity of the bioassay was evaluated by analysis of degraded samples at 50 degrees C, and the results were compared with a pharmacopeial liquid chromatographic method at the time 0, 24, and 48 h. The results demonstrated the validity of the proposed bioassay, which allows reliable quantitation of CFZ in pharmaceutical samples and can be used as a useful alternative methodology for CFZ analysis in routine quality control.