Development of diclofenac sodium loaded magnetic nanocarriers of pectin interacted with chitosan for targeted and sustained drug delivery

A novel spherical magnetic nanocarrier of 100–150 nm dimensions made of pectin interacted with chitosan (MPCh-DS0.05) resulted in 99.5% encapsulation efficiency of diclofenac sodium (DS) as a model drug. Similarly, magnetic nanocarrier made of only pectin crosslinked with Ca2+ (MPDS-0.05) resulted in only 60.6% encapsulation efficiency of DS. The increase in drug encapsulation efficiency (%) in MPCh-DS0.05 batch was due to synergistic drug encapsulation properties of pectin and chitosan. The structural and morphological features of these magnetic nanocarriers were studied by X-ray diffractometry (XRD), Fourier transform infrared-spectrometry (FT-IR), thermogravimetry, electron microscopy and dynamic light scattering (DLS) measurements. The magnetic properties were measured by vibrating sample magnetometer (VSM) and superconducting quantum unit interference device measurements (SQUID). The in vitro drug release was pH sensitive and exhibited sustained release sequentially in simulated gastric fluid (negligible release in 0–2 h), simulated intestinal fluid (∼69% release in 2–5 h), simulated colonic fluid (5–60 h) and also in phosphate buffer at pH 7.4 (0–48 h). The drug release profile in phosphate buffer solution at pH 7.4 was in good agreement with swelling controlled mechanism on the basis of Korsemeyer–Peppas model.