Hydrophilic biodegradable microspheres of interferon-alpha and its pharmacokinetics in mice

The goal of this research was to prepare a kind of hydrophilic sustained release microspheres of interferon-alpha (IFN-alpha), alginate-chitosan microspheres (ACM) of IFN, and investigate its pharmacokinetics in mice. Alginate microspheres of IFN-alpha were first prepared by an emulsion method and further incubated in chitosan to form IFN-ACM. The influences of isopropanol, bovine serum albumin (BSA), and pH adjustment by isoelectric point of IFN were studied. The optimized IFN-ACM was obtained with smooth and round morphology, size of 2.18 +/- 0.43 microm and entrapment efficiency of 40%. All the concentrations of IFN-alpha were determined by IFN assay kits. Finally the pharmacokinetics of IFN-ACM suspension was studied in ICR mice by intramuscular (I.M.) routes. Compared with IFN solution, C(max) of IFN-ACM reduced 2.3-fold, and time to achievement of maximum serum concentrations (T(max)) increased 4-fold. Meanwhile the area under the concentration-time curve (AUC) was the same as that of solution. The concentration-time profiles presented the prolonged serum levels of IFN from IFN-ACM.