Preparation and characterization of toltrazuril polyethyleneglycol 6000 solid dispersions with improved solubility

The current study investigated toltrazuril/polyethyleneglycol 6000 solid dispersions (toltrazuril/PEG6000 SDs) with improved solubility. The SDs were prepared by solvent-melting method with PEG 6000 as carrier. It was validated by differential thermal analysis (DTA) and cumulative dissolution rate. The solubility of toltrazuril, physical mixture and SDs were measured. The ultra violet (UV) spectrophotometer method was developed for the determination of toltrazuril. It was found that the spectra of cumulative dissolution rate, DTA of the SDs were different from the toltrazuril and physical mixture. Solubility of toltrazuril was enhanced for the formation of SDs. The calibration curve was linear with a correlation coefficient r = 0.9998 in range of 4.020.0 µg/mL. The method was simple and practical in preparation and determination the toltrazuril SDs.   Key words: Toltrazuril, polyethyleneglycol 6000, solid dispersions, solubility.