Mucosal drug delivery using cellulose derivatives as a functional polymer

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems

Background:

• Developing nasal powder preparations for peptide delivery requires strategies to enhance drug bioavailability.
• The choice of base materials significantly influences drug absorption and retention in the nasal cavity.

Purpose of the Study:

• To investigate the effect of combining hydroxypropyl cellulose (HPC) and microcrystalline cellulose (MCC) as base materials on nasal drug absorption.
• To understand the role of the drug's microenvironment within these base materials for enhanced peptide delivery.

Main Methods:

• Formulation of nasal powders using combinations of MCC and HPC with model drugs (leuprolide, calcitonin, FITC-dextran).
• Evaluation of drug absorption enhancement and retention on nasal mucosa.
• Analysis of drug distribution within the MCC and HPC components.

Main Results:

• Addition of a small amount of HPC to MCC significantly enhanced the nasal absorption of leuprolide, calcitonin, and FITC-dextran.
• MCC appears to act as an absorption enhancer by creating localized high drug concentrations near the mucosa.
• HPC's gel-forming property increased drug retention on the nasal mucosa.
• Selective drug distribution to MCC was critical for enhanced nasal absorption, more so than distribution to HPC.

Conclusions:

• The microenvironment of drugs within functional base materials critically affects nasal drug absorption.
• Combinations of MCC and HPC can be effectively utilized to improve nasal bioavailability of peptide drugs.
• Understanding drug distribution within the formulation components is key to optimizing nasal delivery systems.