Due to the unique properties of chitosan, a biodegradable natural polymer, it has been introduced as a substitute for various materials used in a wide array of applications, from packaging, tissue engineering to wound dressings and controlled release of drugs [1]. For certain applications, however, chitosan hydrogels may not have the best physicochemical characteristics, or there is an interest in making the hydrogel more responsive to certain environmental characteristics like pH. Hence, the use of reticulate agents and blending other materials became a useful strategy. Gelatine can form a polyelectrolyte complex with chitosan due to the electrostatic interactions between chitosan’s amino groups and gelatine’s carboxyl groups aiding in the gelation process [2]. Meanwhile, glyoxal helps stabilise the hydrogel´s structure, increasing its mechanical strength [3].

In this work, we incorporated gelatine and glyoxal with chitosan to synthetize a hydrogel for the delivery of paracetamol which was then freeze-dried. The samples were then analysed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and swelling, degradation and drug release tests were also performed. Several combinations of chitosan and gelatine were used to find a good balance between porosity, durability and release ability. The systems with best performance were those containing the same gelatine and chitosan concentration (2,5%, w/v) mixed in two different ratios 1:1 and 1:2.