Nanoreticulations of etherified locust bean polysaccharide for controlled oral delivery of lamivudine

Herein, an aqueous solution of etherified locust bean polysaccharide (ELBP) containing lamivudine was reticulated in presence of trivalent aluminium (Al3+) ions to nanoscale level (43.82-197.70 nm) by surfactant assisted homogenization-reticulation technique. The variation in aluminium chloride (AlCl3) strength (1.5-3.5% (w/v)) and drug:ELBP weight ratio (0.11-0.43) affected the properties of the nanoreticulations. Regardless of the variables, a maximum of similar to 44% drug entrapment efficiency was noted. In simulated intestinal fluid (phosphate buffer solution, pH 7.4), the drug release rate was inversely proportional to the strength of AlCl3; but followed a proportional relationship with the drug: ELBP ratio. The mechanism of drug release shifted from Fickian diffusion to anomalous transport as the salt strength was increased above 2.5% (w/v). At intermediate drug:ELBP ratio, the drug release rate was regulated by polymer chain relaxation as opposed to simple diffusion mechanism. Fourier transform infrared spectroscopy did not show any evidence of chemical interaction between the drug and ELBP. Thermal analysis and X-ray diffraction studies suggested amorphous dispersion of drug in the nanoreticulations. Thus, the nanoreticulations were expected to absorb via intestine and phagocytosed by the virus-infected hepatic macrophages and hence could be useful for controlled delivery of lamivudine avoiding dose-dependent toxicity of the drug. (c) 2014 Elsevier B.V. All rights reserved.