This paper describes vitamin C-encapsulated chitosan microspheres cross-linked with tripolyphosphate
(TPP) using a new process prepared by spray drying intended for oral delivery of vitamin C.
Thus, prepared microspheres were evaluated by loading efficiency, particles size analysis, scanning
electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared
(FTIR) spectroscopy, X-ray diffraction (XRD), zeta potential and in vitro release studies. The microspheres
so prepared had a good sphericity and shape but varied with the volume of cross-linking agent
solution added. They were positively charged. The mean particle size ranged from 6.1–9.0 mm. The
size, shape, encapsulation efficiency, zeta potential and release rate were influenced by the volume
of cross-linking agent. With the increasing amount of cross-linking agent, both the particle size and
release rate were increased. Encapsulation efficiency decreased from 45.05–58.30% with the increasing
amount of TPP solution from 10–30 ml. FTIR spectroscopy study showed that the vitamin C was
found to be stable after encapsulation. XRD studies revealed that vitamin C is dispersed at the molecular
level in the TPP-chitosan matrix. Well-defined change in the surface morphology was observed
with the varying volume of TPP. The sphericity of chitosan microspheres was lost at higher volume of
cross-linking agent. The release of vitamin C from these microspheres was sustained and affected by
the volume of cross-linking agent added. The release of vitamin C from TPP-chitosan microspheres
followed Fick’s law of diffusion