The "steric-like" inhibitory effect and mechanism of doxycycline on florfenicol metabolism: Interaction risk

Enhancement of dissolution rate and oral bioavailability of poorly soluble drug florfenicol by using solid dispersion and effervescent disintegration technology

OBJECTIVE

Florfenicol(FF) is an excellent veterinary antibiotic, limited by poor solubility and poor bioavailability.

SIGNIFICANCE

Here in, we aimed to explore the applicability of fast disintegrating tablets compressed from Florfenicol-loaded solid dispersions (FF-SD-FDTs) to improve the dissolution rate and oral bioavailability of Florfenicol.

METHODS

Utilizing selecting appropriate preparation methods and carriers, the solid dispersions of Florfenicol (FF-SDs) were prepared by solvent evaporation and the fast disintegrating tablets (FF-SD-FDTs) were prepared by the direct compression (DC) method.

RESULTS

The tablet properties including hardness, friability, disintegration time, weight variation, etc. all met the specifications of Chinese Veterinary Pharmacopeia(CVP). FF-SD-FDTs significantly improved drug dissolution and dispersion of FF in vitro compared to florfenicol conventional tablets (FF-CTs). A pharmacokinetics study in German shepherd dogs proved the AUC0-∞ and Cmax values of FF-SD-FDTs are 1.38 and 1.38 times more than FF-CTs, respectively.

CONCLUSIONS

Overall, it can be concluded that FF-SD-FDTs with excellent disintegration and dissolution properties were successfully produced, which greatly improved the oral bioavailability of the poorly soluble drug FF, and the study provided a new idea for a broader role of FF in pet clinics.

Study on the Metabolic Transformation Rule of Enrofloxacin Combined with Tilmicosin in Laying Hens

There is often abuse of drugs in livestock and poultry production, and the improper use of drugs leads to the existence of a low level of residues in eggs, which is a potential threat to human safety. Enrofloxacin (EF) and tilmicosin (TIM) are regularly combined for the prevention and treatment of poultry diseases. The current studies on EF or TIM mainly focus on a single drug, and the effects of the combined application of these two antibiotics on EF metabolism in laying hens are rarely reported. In this study, liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to determine the residual EF and TIM in laying hens and to investigate the effect of TIM on the EF metabolism in laying hens. In this paper, we first establish a method that can detect EF and TIM simultaneously. Secondly, the results showed that the highest concentration of EF in the egg samples was 974.92 ± 441.71 μg/kg on the 5th day of treatment. The highest concentration of EF in the egg samples of the combined administration group was 1256.41 ± 226.10 μg/kg on the 5th day of administration. The results showed that when EF and TIM were used in combination, the residue of EF in the eggs was increased, the elimination rate of EF was decreased, and the half-life of EF was increased. Therefore, the use of EF and TIM in combination should be treated with greater care and supervision should be strengthened to avoid risks to human health.