A study of films based on starch and Na‐montmorillonite designed for prolonged release of oxytetracycline hydrochloride

Functional starch‐based nanocomposite films containing Na‐montmorillonite (MMT) and oxytetracycline hydrochloride (OTC) are prepared by the casting method; their structure and transport properties are analyzed. The results of X‐ray difraction and fourier transform infrared spectroscopy measurements show that MMT and OTC participates in the formation of a hydrogen bond network in the starch matrix, leading to a decrease in the film crystallinity degree. The MMT incorporation in the nanocomposites lowers their swelling degree. It is established, that the OTC release from the pure starch film is controlled by the Fickian diffusion mechanism. The MMT particles act as containers capable of holding OTC, as well as crystallite obstacles, limiting the OTC movement within the starch matrix structure. An increase in the MMT concentration from 1 to 5 wt% (based on dry starch) in the films leads to prolonged OTC release. The data on the OTC release from the films with a 3% and 5% MMT content best fits the linear superimposition model. The MMT and OTC have opposite effects on the tensile strength of the starch films. Starch films filled with Na‐montmorillonite for prolonged release of oxytetracycline hydrochloride are prepared. The structure, swelling behavior, mass transport, and mechanical properties of the films are studied. The results show that the produced low‐cost starch/montmorillonite films can potentially be used for local controlled drug delivery.