Eudragit E 100 as a carrier of drugs. The remarkable affinity of phosphate ester group for the dimethylamine groups

GUZMAN, MARIA LAURA; MANZO, RUBEN; OLIVERA, MARIA EUGENIA

MOLECULAR PHARMACEUTICS

AMER CHEMICAL SOC

Lugar: Washington; Año: 2012 p. 2424 - 2424

1543-8384

herapeutic agents containing phosphate groups in their molecules have increasing therapeutic impact. The object of this study was to characterize the cationic polyelectrolyte Eudragit E100 (EuE100) as a carrier for drugs containing phosphate groups, using dexamethasone phosphate (DP) as a model. A series of EuE100-DP complexes was obtained by acid-base reaction in which DP neutralized 12.5-75% of the basic groups of EuE100. The solids obtained after solvent evaporation revealed by spectroscopic characterization the complete reaction between the components through the ionic interaction between the amine groups of EuE100 and the phosphate groups of DP. The reversibility of the counterion condensation, evaluated through the proton withdrawing effect produced by the ionic exchange generated by titration with NaCl, showed a remarkable high affinity between EuE100 and DP. In line, drug delivery in bicompartimental Franz cells towards water as receptor medium was very slow (2% in 6 hs). Howe