An Open Label Study in Healthy Volunteers to Compare Chronocort® to Hydrocortisone

Inclusion Criteria: * Healthy male volunteers between 18 and 60 years of age, inclusive (at screening). * Subjects with a Body Mass Index (BMI) of 21-28. Body Mass Index = Body weight (kg) / (Height (m))2. * Subjects with no clinically significant abnormal serum biochemistry, haematology and urine examination values within 14 days of the start of the study. The parameters measured included those shown in Appendix 3 of the Study Protocol. * Subjects with a negative urinary drugs of abuse screen (including alcohol), determined within 14 days of the start of the study. * Subjects with negative HIV and Hepatitis B and C results. * Subjects with no clinically significant abnormalities in 12-lead electrocardiogram (ECG) determined within 14 days of the start of the study. * Subjects with no clinically-significant deviation outside the normal ranges for blood pressure and pulse measurements. * Subjects and sexual partners must have used effective contraception methods during the trial and for 3 months after the last dose, for example: * Oral contraceptive + condom * Intra-uterine device (IUD) + condom * Diaphragm with spermacide + condom * Subjects must have been available to complete the study. * Subjects must have satisfied a medical examiner about their fitness to participate in the study. * Subjects must have provided written informed consent to participate in the study. Exclusion Criteria: * A clinically significant history of gastrointestinal disorder likely to influence drug absorption. * Receipt of regular medication within 14 days of the first study day (including high dose vitamins, dietary supplements or herbal remedies). * Evidence of renal, hepatic, central nervous system, respiratory, cardiovascular or metabolic dysfunction. * A clinically significant history of previous allergy / sensitivity to Hydrocortisone. * A clinically significant history of drug or alcohol abuse. * Inability to communicate well with the Investigator (i.e., language problem, poor mental development or impaired cerebral function). * Participation in a New Chemical Entity clinical study within the previous 16 weeks or a marketed drug clinical study within the previous 12 weeks. * Subjects who had consumed more than 2 units of alcohol per day within seven (7) days prior to the first dose or had consumed any alcohol within the 48 hour period prior to the first dose. * Donation of 450ml or more blood within the previous 12 weeks. * Subjects who worked shifts (i.e. regularly alternated between days, afternoons and nights).