Spray-Dried Chitosan-Clay Nanocomposite Gels as Binders: Enhanced Compressibility and Micromeritic Properties of Lactose-Based Granules for Poorly Compressible Drug Tablets

Background/Objectives: Nanocomposites of chitosan (CH) and magnesium aluminum silicate (MAS) clay can be produced by spray drying. This study aimed to characterize and evaluate spray-dried chitosan (SDCH) and SDCH-MAS nanocomposites, which were prepared using CH with MWs of 400 kDa (4M) and 800 kDa (8M), as binders of lactose granules containing propranolol HCl (PPN) and crude powder from Andrographis paniculata (ADP) intended for tablet formulation. Methods: Lactose granules were produced using SDCH and SDCH-MAS composites via wet granulation, and the granule properties were compared with those obtained using polyvinylpyrrolidone (PVP K30). The lactose granules incorporating PPN and ADP crude powder were also prepared and compressed into tablets. The physical properties of both granules and tablets were evaluated. Results: SDCH-MAS composites formed intercalated or exfoliated nanocomposites, as proved by PXRD, and rapidly hydrated in water to form gels that functioned as binders. Lactose granules prepared with SDCH and SDCH-MAS composites exhibited fair to good flowability and demonstrated lower yield pressure and yield strength during plastic deformation than those prepared with PVP K30. Moreover, granules loaded with PPN offered acceptable flowability and could be compressed into tablets. Increasing MAS content reduced the disintegration time of tablets in 0.1 N HCl. The use of SD4MCH in tablets could retard PPN release, while the addition of MAS accelerated drug release. For ADP crude tablets with a 75:25 ADP-to-lactose ratio, acceptable hardness and friability were achieved when SD4MCH-MAS 1:0.6 composites and PVP K30 were used, and 75% of andrographolide dissolved within 30 min. Conclusions: SDCH-MAS nanocomposite gels are effective binders for lactose granules in wet-granulated tablets.