Mucosal drug delivery using cellulose derivatives as a functional polymer

In order to develop nasal powder preparations with higher bioavailability f or peptide delivery, the effect of a combination of hydroxypropyl cellulose (HPC) and microcrystalline cellulose (MCC) used as base materials and micr oenvironment for the drugs in the preparations was examined. Significant en hanced absorption of leuprolide, calcitonin and FITC-dextran was attained b y the addition of a small amount of HPC to MCC. It is suggested that MCC wo rks as an absorption enhancer by causing a locally high concentration of dr ugs in the vicinity of the mucosa surface. On the other hand, HPC works to increase retention of drugs on the nasal mucosa due to its gel-forming prop erty. In comparison to the powder mixtures of MCC and HPC in which drugs we re distributed to the MCC or HPC, selective distribution of drugs to MCC is shown to be a critical factor for enhancing nasal absorption. These result s showed that the microenvironment of drugs in the functional base material could critically affect the nasal absorption of drugs. (C) 1999 Published by Elsevier Science B.V. All rights reserved.