Biopolymers such as carrageenan or collagen can be used as carriers for loading a drug to enhance a drug’s bioavailability. In this work, allopurinol was loaded on a carrageenan/collagen blend and the carrageenan/collagen/allopurinol (CCA) biocomposite films were prepared using the ionic gelation method combined with the 3D printing method using carrageenan/collagen/allopurinol gel as a 3D printing ink material. The advantages of the 3D printing method are the ease in shaping the design of films and the ease in controlling the thickness of films. The results of infrared (IR) spectroscopy and field emission scanning electron microscopy (FESEM) analyses showed that the CCA biocomposite films have a regular structure, and the functional groups of components in the biocomposites can interact with each other. After 30 minutes of immersion in distilled water and pH buffer solution, the biocomposite films swelled and disintegrated. The carrageenan/collagen blend can control the release of allopurinol in simulated body fluids. In addition, the drug release kinetic models reflecting the release process of allopurinol from CCA biocomposite films in simulated body fluids have also been calculated.

In this work, collagen extracted from fresh-water fish scales has been used as a matrix in the drug delivery polymeric system. Allopurinol has been applied to reduce the concentration of uric acid in blood and used as a model drug in collagen drug delivery system. The functional groups in collagen/allopurinol biocomposite as well as the morphology of this material were assessed by infrared (IR) spectroscopy and scanning electron microscopy (SEM). Allopurinol content released from collagen/allopurinol biocomposite in simulated body fluids was determined based on the optical absorbance of solutions containing drug by ultraviolet – visible (UV-Vis) spectra and allopurinol calibration equations. The analysis results of IR spectra of biocomposite samples indicated that the collagen/allopurinol biocomposite contains N–H, C–H, O–H linkages in collagen and C=O, C=N, N-H linkages in allopurinol. The SEM images showed that the morphology of collagen/allopurinol biocomposites differs to that of allopurinol. The allopurinol could release from the biocomposites in simulated body fluids (pH 2 and pH 7.4) according to two stages: fast release stage for 1 first hour and slow release stage in following hours. At the same time of testing, the content of allopurinol released from collagen/allopurinol biocomposite is higher than that from allopurinol free (allopurinol unloaded by collagen).