In vitro studies of the properties of thermosensitive systems prepared on Pluronic F-127 as vehicles for methotrexate for delivery to solid tumours.

The aim of the trial was to prepare a thermosensitive vehicles for methotrexate which, after implantation to a solid tumour, could form in situ a specific implant releasing the active substance at the site of application. Pluronic F-127 with certain additives, i.e. lactose, glucose, propylene glycol, glycerol and sodium phosphate was used for investigations. The sol-gel transition temperature of the obtained systems at increasing temperature and various shear rates as well as their physicochemical properties were investigated. All the prepared systems underwent sol-gel transition at physiological ranges of temperature. Methotrexate release from selected formulations approached zero order kinetics and the investigations have shown that the use of Pluronic F-127 at concentration of 14.8% in the construction of drug carriers enables to obtain such a form that, depending on the presence of additives and their concentration, provides active substance release at any time. Analysis of physicochemical properties of the investigated formula tions, i.e. pH, osmotic pressure, density allows to believe that their administration by means of a thin needle should not be problematic and they will not irritate tissues or cause pain after application.