Estudios viscosimétricos para evaluar el fenómeno de asociación entre el EUDRAGIT e-100® modificado y la carbamazepina en medio acuoso.

This project intended to assess the phenomenon of chemical association of the polymeric material, Hydrochloride Eudragit E-100, with a reference drug, as carbamazepine, using a methodology of capillary viscometry, previously standardized. A capillary viscometer known as Oswald or Ubbelohde viscometer, whose experimental measurement parameter is the flow time, or run-time was used. The run-time values have an indirect relationship with the relative viscosity, thereby allowing for differences between the relative viscosities of the polymer solutions Hydrochloride Eudragit E-100 in the presence and absence of drug. The determination of the run-time values were taken at 37 ° C, and pH values corresponding to 1.2, 2, 4, 6, 7.4, 8, and 10. We found that the standardized method showed a property repeatability and intermediate precision. Also, an effect of concentration and ionic strength of the medium in the relative viscosities of the ionomer solutions was obtained. And, a conformational transition phenomenon of Hydrochloride Eudragit E-100 in function of the pH of the medium was checked. This made possible to obtain a marked effect on the rheological behavior of the polymer solutions in the presence and absence of carbamazepine, thereby assuming a potential phenomenon of polymer-drug association. Moreover, we obtained that carbamazepine or model drug does not affect the viscosity of the aqueous media.