A fast and reliable method of liquid chromatography and ultraviolet detection of sulfaguanidine, sulfadiazine, sulfamethazine, sulfamethizole, and sulfamethoxazole in feedingstuffs was described. The method involves THE procedure of preparation of spiked samples, and extraction of sulphonamides from the matrix using a mixture of methanol and acetonitrile, followed by drying the extract and dissolving it in a phosphate buffer. The analysis uses octadecyl (C18) analytical column with UV detection at λ = 260 nm and a gradient programme of mobile phase composition. The analytical procedure has been successfully adopted and validated for quantitative determination of the sulfonamides in feedingstuff samples. Validation included sensitivity, specificity, linearity, repeatability, and intra-laboratory reproducibility. The mean recovery of sulfonamides was 84%, within the working range of 200-2000 mg/kg. Direct, simple sample preparation and HPLC-UV analysis allow the method to be successfully included in the scope of routine analyses. The presented results could be an answer to a need of simple and easy method for sulfonamide determination applicable in medicated feedingstuffs analysis.

A liquid chromatography-ultraviolet detection method for the determination of florfenicol (FF) and thiamphenicol (TAP) in feeds is presented. The method comprises the extraction of analytes from the matrix with a mixture of methanol and acetonitrile, drying of the extract, and its dissolution in phosphate buffer. The analysis was performed with a gradient programme of the mobile phase composed of acetonitrile and buffer (pH = 7.3) on a Zorbax Eclipse Plus C18 (150 × 4.6 mm, 5 µm) analytical column with UV (λ = 220 nm) detection. The analytical procedure has been successfully adopted and validated for quantitative determination of florfenicol and thiamphenicol in feed samples. Sensitivity, specificity, linearity, repeatability, and intralaboratory reproducibility were included in the validation. The mean recovery of amphenicols was 93.5% within the working range of 50-4000 mg/kg. Simultaneous determination of chloramphenicol, which is banned in the feed, was also included within the same procedure of FF and TAP stability studies. Storing the medicated feed at room temperature for up to one month decreased concentration in the investigated drugs even by 45%. These findings are relevant to successful provision of therapy to animals.

Summary.A high-performance liquid chromatographic (HPLC) method with fluorescence detection after precolumn formaldehyde derivation was developed to detect concentrations of amoxicillin (AMX) in poultry plasma. Proteins in plasma samples spiked with AMX were precipitated with a phosphate buffer and trichloroacetic acid. After precolumn treatment of the extraction product of AMX with formaldehyde under acidic and heating conditions, HPLC analysis with fluorescence (FL) detection at an excitation wavelength of 355 nm and an emission wavelength of 450 nm was performed. A mobile phase comprising acetonitrile and a buffer solution (0.05 M KH2PO4 pH = 5.6), which yielded AMX retention time 8.58 min, was suitable for detection of AMX. The calculated standard curve of the reaction product was linear, and the correlation coefficient was greater than 0.999. The limit of detection and quantification, the accuracy, and the precision were evaluated. Recoveries of spiked amoxicillin were >92%, with a coefficient of variation in the range of 0.35-0.89%. This method has been successfully applied to a pharmacokinetic study after oral administration of amoxicillin to poultry.

The aim of the study was a preliminary assessment of the anti-cancer efficacy of the capsaicin-containing habanero pepper extract in dogs. The study was conducted on a group of 50 dogs (33 females, and 17 males aged 6–18 years) diagnosed with different tumours, and 20 dogs (12 females and 8 males, aged 2-12 years) forming a control group. All animals were administered with a diet supplement based on habanero pepper extract containing capsaicin. Observations were conducted for a period of 6 months, during which time the general condition of the animals administered with the extract was monitored, and haematological as well as biochemical examinations were conducted at 2-week intervals in order to assess the tolerance of the animals to the extract. In the animals of the test group, tumour sizes were measured at monthly intervals. After the end of observations, the tumours were removed and subjected to histopathological tests. As a result of habanero pepper extract administration, the tumour size decreased by 5–50% in 15 dogs, the tumours size remained unchanged in 29 dogs, whereas tumour size increased by 10–30% in 5 animals despite the administration of the extract. The extract was well tolerated by the animals. Temporary undesirable symptoms in the form of vomiting or diarrhoea and licking of the anal region, which could stem from its administration, were observed in only nine dogs of the test group and 5 of the control group. An increase in asparagine aminotransferase (AST) activity was observed in 13 dogs of the test group, alanine aminotransferase (ALT) activity was elevated in 11 dogs, whereas alkaline phosphatase (ALP) increased its activity in 18 dogs. Increases in total bilirubin, urea and creatinine concentration were noted in the serum of 10, 9 and 9 dogs respectively. In the control group, the AST activity increased in 7 dogs, ALT in 5, ALP in 5, and total bilirubin concentration in 6. The preliminary clinical observations indicate that the capsaicin-containing habanero pepper extract exhibits favourable effects on different tumours in dogs and is well tolerated by the animals, thus the obtained results are a good sign for future studies on alternative medications used in dog oncology.

The aim of this article was to assess the anticancer effectiveness of habanero pepper extract containing capsaicin on two dog cancer lines, DAN (fibroblasts isolated from osteosarcoma) and D-17 (epithelium cells of osteosarcoma obtained from pulmonary metastatic tumors), under in vitro conditions. The experiment was carried out in a suspension of D-17 and DAN line cells with a density of 12 × 105 cells/mL in a culture fluid with 10% of FBS. After 24 h of incubation (37 °C, 5% CO2), the fluid above the culture was removed, and diluted habanero pepper extract was added. The concentrations of capsaicin in the extract were 10, 20, 50, 100, 150, and 200 µM (in the culture fluid with 10% of FBS). The cells were incubated for 24-96 h (37 °C, 5% CO2). After the incubation period, cytotoxicity assessment of the habanero pepper extract and cell proliferation impairment by the habanero pepper extract in a suspension of cell lines, in MTT test, as well as the cytometric examination of viability of cancer cells exposed to the habanero pepper extract were performed. The results indicate that the extract shows better anticarcinogenic activity in vitro compared with pure capsaicin. Confirmation of the anticancer effectiveness of the extract on the cells is a starting point for wide clinical observations and a good indication for further research.