Release kinetics of [lidocainium][ibuprofenate] as Active Pharmaceutical Ingredient-Ionic Liquid from a plasticized zein matrix in simulated digestion

An in vitro approach is proposed to study the release of an Active Pharmaceutical Ingredient-Ionic Liquid (API-IL) from a natural biopolymer matrix based on zein, a maize storage protein. Zein can be processed in the molten state with 20 w% [Lidocainium][Ibuprofenate] added as API-IL also acting as plasticizer and potentially co -plasticized by glycerol. The thermal stability of the matrix is checked, as well as the in vivo biological activity of the API-IL confirming anesthetic and anti-inflammatory activities. Model tablets are thermomolded at 130 degrees C ( null 20 mm, 0.2 mm thick) and submitted to simulated digestion based on the INFOGEST static protocol of gastrointestinal food digestion at 37 degrees C (2 h under gastric conditions followed by 2 h under intestinal ones). The release of the API-IL is evaluated by HPLC-UV to dissociate lidocainium, that shows a progressive release (35 % after 2 h and 60 % after 4 h digestion), from ibuprofenate, that is mainly released under intestinal conditions due to low solubility in acidic conditions. The monitoring of the tablets reveals release mechanisms based on diffusion without noticeable erosion of the matrix. These results demonstrate the interest of this thermoplastic material to provide a relevant drug delivery system.

Automated summary

In this study, an in vitro approach was used to investigate the release of an Active Pharmaceutical Ingredient-Ionic Liquid (API-IL) from a natural biopolymer matrix based on zein. The results demonstrated that the matrix had good thermal stability and in vivo biological activity, and the release of the API-IL was mainly achieved through a diffusion mechanism.