← Back to Search
Characterization Of Degradable Starch Microspheres As A Nasal Delivery System For Drugs
Published 1990 · Chemistry
Abstract Intranasal administration of starch microspheres and insulin as a dry powder results in a rapid decrease in plasma glucose. The optimal dose of spheres for a given dose of insulin is approx. 3–7 mg per kg body weight in the rat. The degree of cross-Unking governs the water uptake and swelling and thereby the release of insulin from the spheres in vitro. No significant differences could be seen in vivo between spheres with different swelling factors. Starch microspheres do not induce erythrocyte hemolysis. A comparison between microspheres and starch powders (molecular weights: 25 000 and 11 000, respectively) shows that the insoluble starch of mol. wt. 25 000 and the microspheres reduce the plasma glucose level to the same extent. Water-soluble starch powder (mol. wt. 11 000) does not affect the plasma glucose level. The crucial properties for the absorption-promoting effect of microspheres are water absorption and water insolubility.