Bioadhesive drug delivery group

Overview

Despite the tremendous advances in drug delivery, the oral route remains the preferred route for the administration of drugs due to low-cost manufacturing, ease of administration and high level of patient compliance.

However, significant barriers present for the peroral administration of drugs, such as hepatic first pass metabolism, variable absorption and drug degradation within the GI tract prohibiting the oral administration of several classes of drugs.

Consequently, other absorptive mucosae are being considered as potential sites for drug administration, including the mucosal linings of the nasal, rectal, vaginal, ocular, and oral cavity.

Among these, the oral mucosa (such as buccal/sublingual mucosa) has many properties such as easy accessibility, excellent blood supply, by-pass of hepatic first-pass metabolism, rapid repair and excellent permeability profile, that make it an attractive site for drug delivery but also provides several challenges for researchers.    

The buccal and sublingual routes, in particular, present favourable opportunities and many formulation approaches have been explored so far for such an application; although the current commercially available formulations are mostly limited to tablets and lozenges.

Oral mucoadhesive dosage forms will continue be an exciting research focus for improving drug absorption especially for the new generation of the so called ‘biologics’.

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 in vivo methods are essential tools to assess the performance of buccal drug delivery systems and to predict their in vivo behaviour.

However, a lack of standardised methodologies for the systematic evaluation of buccal 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.

What the group does

The bioadhesive drug delivery group focuses on formulation development and characterisation of novel drug delivery systems, such as:

• quick/slow dissolving thin films/wafers
• orally disintegrating mini-tablets and multiparticulate systems aimed at delivering the drug via buccal/sublingual mucosa
• developing and validating the in vitro models for characterisation of transmucosal drug delivery system

The group also focuses on developing age-appropriate formulations to overcome the formulation-related issues responsible for poor patient compliance and adherence.