Preparation and characterization of halloysite nanotubes containing hydrogels for controlled release drug delivery of cetirizine dihydrochloride.

The objective of the present study was to improve the mucosal adherence of nasal formulations through the application of swellable, microporous drug containing crosslinked hydrogels. Halloysite nanotubes (HNTs) alone, poly acrylic acid/poly-vinyl-alcohol (PAA/PVA) hydrogels and poly acrylic acid/poly-vinyl-alcohol)/Halloysite nanotubes (PAA/PVA/HNTs) hydrogels were prepared by free-radical polymerization. N–N methylene bisacrylamide (MBA) and ammonium per-sulfate (APS) were used as cross-linker and initiator, respectively. Studies of Diffusion coefficient, swelling, porosity, loading and drug release at various pH medium, mucoadhesive strength and impact on Caco-2 cell viability were conducted. The drug, HNTs and hydrogels were evaluated by FTIR, SEM and XRD. An increase in gel fraction, porosity and drug loading capacity of PAA/PVA/HNTs was observed compare to PAA/PVA hydrogels, which may be due to increased available surface area. The drug loading capacity showed a direct relationship with the HNTs concentration of 25 to 75% in the PAA/PVA/HNTs hydrogels. The presence of carboxylic acid, hydroxyl, aluminum, silicate groups was observed in the FTIR spectrum. The SEM showed a uniform structure of the PAA/PVA hydrogels but became a encrusted like structure in the PAA/PVA/HNTs hydrogels. The PAH2 formulation showed a mucoadhesive strength more than 80% and the cell viability studies did not reveal a significant difference between the control and dispersion of HNTs and PAA/PVA, PAA/PVA/HNTs. [ABSTRACT FROM AUTHOR]