Gelatin Films and its Pregelatinized Starch Blends: Effect of Plasticizers

This study aimed to develop gelatin (GEL) and gelatin/Alpha starch (GEL/αSt) dissolving films as drug delivery by casting method. Because these films were brittle and lack of elasticity, therefore, glycerin (GLY), propylene glycol (PG) or polyethylene glycol 400 (PEG) in various amounts (5-30 part per hundred of gelatin; phg) was used as plasticizer. It was found that all types and amounts of plasticizer could be blended into gelatin solution and the transparent GEL films were formed, except the GEL/PEG films presented in opaque characteristics. However, 30 phg GLY blended film was too softy. Increasing amount of plasticizer caused a decrease in tensile strength and increase in elongation at break (EAB) of films. These GEL films swelled, dissolved and eroded in 2 hours. The αSt was also blended, and the effects of αSt amounts (5-30 phg) and plasticizer types (at 25 phg) on GEL film properties were studied. The αSt dispersions mixed well in gelatin solution and gave homogenous films. The swelling and erosion of GEL/αSt films in water were faster than those of GEL films. Increasing αSt amount prolonged the swelling time and decreased the degradation rate of GEL/αSt films. The tensile strength of GEL/αSt/GLY films slightly increased when the αSt amount increased but those of PEG and PG blended films were not different. The EAB of all plasticizer blended films decreased when the amount of αSt increased. Either lidociane or lidociane hydrochloride was mixed in GEL/αSt/GLY dissolving films to use as local anesthetic. The morphology, Fourier Transform Infrared Spectroscopy confirmed their compatibilities in these films, but Differential Scanning Calorimeter showed some changes that should be further evaluated.