Synthesis of novel poly (vinyl alcohol)/tamarind gum/bentonite-based composite films for drug delivery applications

In this study, a series of novel composite films comprised of poly (vinyl alcohol) (PVA), tamarind gum (TG), and bentonite clay particles were prepared using the solvent casting method. The prepared composite films appeared colorless and transparent. Ultraviolet-visible (UV-vis) spectroscopy revealed that the prepared films showed higher absorption in the UV region as compared to the visible region. Bright-field microscopy analysis showed that the matrix of the films contained globular architectures. The analysis of the surface topological features of the prepared films suggested the agglomeration of clay particles in the PVA/TG matrix when the bentonite content was higher. Bentonite-containing films had higher %swelling as compared to the control (PVA/TG) film. FTIR spectroscopy indicated that the incorporation of the bentonite clay enhanced the hydrogen bonding among the components of the films. X-ray diffraction analysis of the films suggested the intercalation of polymer chains within the bentonite clay layers when the bentonite content was lower. However, the filler particles assumed agglomerated forms as the loading concentration of bentonite was increased, which was in agreement with SEM analysis. On the other hand, mechanical studies suggested that above a critical amount (i.e., 20 mg), bentonite weakened the network structure of the films. The resistive component of the films showed a gradual increment with a corresponding rise in the bentonite content. The in vitro release study confirmed that the films loaded with ciprofloxacin HCl supported the sustained diffusion of the drug molecules and hence, can be utilized for controlled drug delivery applications. Moreover, the drug-loaded films showed an effective antimicrobial effect against Gram-positive and Gram-negative microbes as compared to the control films. In gist, the above analyses suggested that the prepared PVA/TG/bentonite films have promising potential to be utilized as drug delivery systems.