A Healthy Volunteer Study to Investigate the Relative Bioavailability of Two Forms of GSK598809 Capsules.

An Open Label, Randomised, Single Dose, Three-way Crossover Study to Investigate the Relative Bioavailability of a 100mg Capsule Compared to Four 25mg GSK598809 Capsules and the Effect of Food on the Pharmacokinetics of the 100mg Capsule in Healthy Male and Female Volunteers.

Study to compare PK of a new 100mg capsule with four 25mg capsules. This is required because we plan to have only single capsules administered in the later phase clinical trials but we have not had a 100mg strength before. As this is a new previously untested strength we need to ensure that the PK is similar to that achieved using 4 x 25mg. The study will also assess the effect of high fat food on the PK of the 100mg capsule. The study is planned to consist of a single part , with three dosing periods, periods 1-3 consisting of 16 subjects. There will be a week wash out between each dose. In the three dosing periods subjects will either received 4x25 mg GSK598809 capsule in a fasted state, 100mg capsule in a fasted state or 100mg GSK598809 capsule in a fed state. Subjects will return to the centre for follow-up 7-14 days after the final dose. It is expected that the total duration of the study should be approximately eight weeks.

Inclusion:

• Healthy as determined by responsible physician.
• Male or female between 18 to 65 years old.
• Females of non-child bearing potential and females of child-bearing potential that agree to use appropriate method of contraception for appropriate amount of time.
• Males that agree to use appropriate method of contraception for appropriate amount of time.
• Neither too fat nor too thin.
• Capable of giving written informed consent and being compliant with requirements within the informed consent.

Exclusion:

• Any current medical or psychiatric illness.
• Any history of chronic medical or psychiatric illnesses.
• Previous or current alcohol or drug abuse/dependence including nicotine.
• Female subjects must not be breastfeeding or been breastfeeding for a month.
• Serum prolactin exceeding normal range.
• Personal or family history of prolonged QTc syndrome.