Mucosal drug delivery

Overview

Mucosal drug delivery involves administration to moist cavities, such as the lining of the mouth, vagina, and bladder. This allows for high drug concentration in local treatment of disease with reduced systemic side-effects. The mucosal route can avoid significant drawbacks present for the oral administration of drugs, such as hepatic first-pass metabolism, slow absorption, and drug degradation within the gastrointestinal tract, without the need for painful injectable products.

Whilst mucosal drug delivery offers exciting opportunities for novel therapies, there are several challenges present which require specialist expertise to overcome. Importantly, the palatability and irritancy and formulation retention at the site of application need to be considered in the design of such medicines. Robust and validated in vitro and ex vivo methods are essential tools to assess the performance of mucosal drug delivery systems and to predict their in vivo behaviour.

However, a lack of standardised methodologies for the systematic evaluation of mucosal drug delivery systems is apparent. Significant work is still needed to develop models which are able to derive in vitro and in vivo correlations for such systems. Mucoadhesives are often included in mucosal formulations to enhance retention, however techniques for evaluating this adhesion are limited, and not validated. The common use of semi-solid medicines for mucosal delivery also introduces issues of stability for many drugs.

What the group does

The mucosal drug delivery group focuses on formulation design and characterisation, supported by in vitro/ex vivo model development.

Specific research interests include:

• Quick/slow dissolving thin films/wafers, orally disintegrating mini-tablets and multi-particulates systems aimed at delivering the drug via buccal/sublingual mucosa
• Developing and validating in silico/in vitro/ex vivo models for characterisation and design of transmucosal drug delivery systems
• Mucoadhesive formulations including 'thermogelling' systems which transition from solution to gel upon application, and their rheology.