Enhanced oral absorption of salmon calcitonin-encapsulated PLGA nanoparticles by adding organic substances

• DOI: 10.1007/s11814-009-0020-2
• Publication Date: 2009-01-27T07:32:42Z
• Authors: Tae-Sung Jung; Byung-Soo Kwon; Hea-Eun Lee; Ah-Young Kim; Min-Jeong Lee; Cho-Rong Park; Ho-Kyung Kang; Young-Deug Kim; Sang-Kil Lee; Jae-Seon Kang; Guang-Jin Choi
• Keywords: Nanocapsules; PLGA

Two organic compounds with potential absorption enhancing effects, bile acids and transferrin, were examined by the gastro-intestinal (GI) absorption of therapeutic salmon calcitonin (sCT) as encapsulated by poly(lactide-co-glycolide) (PLGA) for the treatment of osteoporosis. The sCT-loaded PLGA nanocapsules were prepared by O/W emulsification approach. Either additive of a designated content was mixed with sCT dissolved in methanol. For bile acids, their content (0–7.5 mg to sCT 6 mg) was observed to have a substantial effect both on the emulsification process and the encapsulation efficiency. When 1.5 mg of bile acids was added, sCT-loaded PLGA nanocapsules of about 700 nm in diameter and with a fairly high encapsulation efficiency greater than 35% were produced. Accordingly, this formulation gave the most significant hypocalcemic effect in an in vivo experiment with SD rats. On the other hand, a too high bile acids loading resulted in a poor encapsulation efficiency of less than 7%. Two principal roles of bile acids were proposed: emulsifying agent and absorption enhancer. Transferrin, a human glycoprotein of 80 kDa molecular weight, turned out to have potential as absorption enhancer as well.