Preparation of the porous ZIF-8 and the behaviors of loading ibuprofen

Oral bioavailability of poorly soluble drugs is severely limited due to their low solubility. In recent years, metal-organic frameworks (MOFs) materials have attracted much attention because of their hydrophobicity and high specific surface area. In this paper, the porous ZIF-8, one of MOF family materials, were prepared by solution co-precipitation method. The specific surface area and pore size distribution of ZIF-8 were optimized by changing the molar ratio of Zn²⁺ to 2-Methylimidazole. In addition, ZIF-8 were used as the carrier for ibuprofen (IBP), a poorly soluble drug, and its loading performance was studied in detail. The results showed that when the molar ratio of Zn²⁺ to 2-methylimidazole was 1∶8, ZIF-8(8) had the largest specific surface area (1187 m²/g) and pore volume (1.183 cm³/g). And the loading capacity of ZIF-8(8) on IBP was as high as 21.8%. The drug carrier composite (IBP-ZIF-8(8)) showed a well dissolution rate in vitro, and its cumulative dissolution rate was about 98% in phosphate buffer solution with pH of 2.5 and 7.4. The survival rate of RAW246.7 cells treated with IBP-ZIF-8(8) was over 94%, demonstrating satisfied biosafety. ZIF-8(8) with excellent specific surface area, pore volume, good loaded-IBP performance and biosafety has great potential applications in drug controlled-release system.