The influence of pH, temperature and salt on the ethanolic desolvation of dilute gelatin solutions

Abstract

Gelatin, the denaturation product of the protein collagen, has been found to be a suitable candidate for the production of nanoparticles for drug delivery systems. The production of these nanoparticles involves the coacervation of the protein by various methods. One such method is the addition of a nonsolvent, such as ethanol, to aqueous solutions of the polymer. However, the alteration of the net charge on gelatin in solution, by variation in the solution pH affects the overall response of the protein to the non-solvent. The ionic strength and the temperature of the gelatin solution are also important factors which determine the behaviour of gelatin on addition of ethanol. In order to be able to design a robust method for the preparation of nanoparticles in this way, it is important to fully understand the phase behaviour of gelatin under various solution conditions. The response of lime-cured gelatin of to the non-solvent ethanol under different conditions of temperature and pH and dilute sodium chloride solutions was therefore studied.