Investigations with another compound produced a range of formulations including lipid liquid delivery, solid micronised powder delivery and a solid suspension in a lipid based semi-solid format.

These systems were again progressed to PK studies in Dogs. The results showed the following in terms of increasing bioavailability: dry powder < semi-solid < liquid lipid. However large variations were seen inter-patiently; intra-patient variability was also of concern using the powder formulation. This was not seen through delivery of the semi-solid formulation which produced much more consistent plasma profiles through the subject groups.

Following a review of the increase in bioavailability, patient variability, formulation cost and complexity of manufacture, the semi-solid lipid based formulation was selected for progression into phase I studies. The formulation to date has progressed to phase IIb studies.

The next graph shows the increase in plasma concentration achieved by the semi-solid formulation compared to the dry powder delivery system.