Solubilidad y volúmenes de desplazamiento del acetaminofén en mezclas binarias formadas por agua, etanol y propilenoglicol a 25,0 °C

The solubility and displacement volumes of acetaminophen in binary mixtures composed by propylene glycol (PG), ethanol (EtOH), and water (W) were determined at 25.0 °C. The solubility increases in the W-EtOH system as the EtOH proportion increases in the mixture reaching the maximum value in the mixture 80 % p/p of EtOH, whereas, the solubility increases in the W-PG system as the PG proportion increases in the mixture reaching the maximum value in the mixture 90 % p/p of PG, and finally, in the EtOH-PG system, the solubility increases as the PG proportion increases reaching the maximum in the mixture 30 % p/p of PG. It was found that displacement volumes depend on the drug concentration in addition to the composition of cosolvent mixtures, elsewhere this pharmaceutical property may be considered approximately constant as 0,80 mL/g in the W-EtOH system, 0.80 mL/g in the W-PG system and on the other hand, 0.77 mL/g in the EtOH-PG system, at the same temperature.