Pharmaceutics - Research

Oral drug delivery

Identification of a formulation that affords clinically adequate blood levels after oral administration is a major milestone in the development and commercialisation of a drug molecule. Whilst alternate route of delivery (nasal, pulmonary, transdermal etc) have specific application to particular pharmaceutical problems, oral delivery remains the preferred route of delivery in most cases.

When a drug is administered orally, a complex cascade of events must occur before the drug is absorbed into the bloodstream and available to exert the desired pharmacological effect. Of key importance are the chemical characteristics of the drug and the nature and composition of the formulation as these play crucial roles in defining the release from the delivery system, dissolution within the GI lumen and permeation across the intestinal mucosa.

Research at the Victorian College of Pharmacy is being conducted using both in vitro and in vivo models of drug absorption to examine the impact of formulation components on the dissolution and gastrointestinal permeability of both typical ‘small’ molecules and is also examining the particular challenges presented by large macromolecular materials such as peptides and proteins. Specific projects are also focused on drug access to the lymphatic system after oral delivery, since this route of drug transport to the circulation may have benefits both in terms of drug targeting and avoidance of drug metabolism and the utility of lipid based delivery systems to promote the absorption of poorly water soluble drugs into both the blood and the lymphatics after oral administration.

Specific research projects include

• Factors affecting the delivery of drugs across intestinal mucosa
• Intestinal lymphatic transport of drugs
• Oral bioavailability
• Dissolution of micronised, poorly water soluble drugs
• Approaches to assist the absorption of hydrophilic molecules
• Lipid based formulation design
• Buccal delivery of drugs
• The role of intracellular binding proteins in drug permeability
• Delivery of drugs to tumour cells: significance of drug metabolism