Smart karaya-locust bean gum hydrogel particles for the treatment of hypertension: Optimization by factorial design and pre-clinical evaluation

This investigation was undertaken to unveil the controlled drug delivery and preclinical anti-hypertensive potential of a novel interpenetrating biopolymer-based network of karaya gum and carboxymethyl locust bean gum (CLBG). The Williamson synthesis of CLBG was confirmed after analyzing FTIR spectra, degree of O-carboxymethyl group substitution and viscosity. The hydrogel particles (HPs) were developed using aluminium chloride solution as cross-linker. A full 32 factorial design approach was adopted for the optimization of two responses: drug entrapment efficiency and drug release (%) in simulated gastrointestinal conditions at 10 h. FE-SEM images and EDX spectra supported the formation of spherical HPs and successful entrapment of the drug in the HPs. Depending upon formulation variables, the drug entrapment efficiency of the HPs lied in the range of 84-98%. The HP matrix was chemically compatible for carvedilol phosphate as was suggested by infrared, thermal and x-ray analyses. The swelling kinetics of HPs corroborated well with the pH-dependent in vitro drug discharge characteristics. The drug release from HPs was found to follow anomalous transport mechanism with varying contribution of simple diffusion and polymer relaxation as was elucidated by Peppas-Sahlin model equation. Preclinical data suggested that the optimized HPs had an excellent blood pressure lowering activity in male Swiss albino mice up to 10 h.