A Study of Chronocort® Versus Cortef ® in Healthy Adult Male Subjects

Inclusion Criteria: 1. Healthy male subjects between 18 and 45 years of age inclusive (at screening). 2. A BMI of 18-30 kg/m2 (inclusive). 3. No clinically significant abnormal serum biochemistry, haematology or urine examination values as defined by the Investigator. 4. A negative urinary drugs of abuse screen. A positive alcohol test or drugs of abuse test may be repeated at the discretion of the Investigator. 5. Negative HIV and Hepatitis Band C results. 6. No clinically significant abnormalities in 12-lead ECG as defined by the Investigator. 7. No clinically significant deviation outside the normal ranges for blood pressure and heart rate measurements as defined by the Investigator. 8. Subjects (unless anatomically sterile or where abstaining from sexual intercourse is in line with the preferred and usual lifestyle of the subject) and sexual partners must use 2 effective contraception methods during the trial and for 3 months after the last dose, for example: * Oral, injected or implanted hormonal contraceptive+ condom * Intra-uterine device (IUD) + condom * Diaphragm with spermicide + condom 9. Subjects must be available to complete both periods of the study and the follow-up visit. 10. Subjects must satisfy a medical examiner about their fitness to participate in the study. 11. Subjects must be able to read and understand the informed consent form and must provide written informed consent to participate in the study. Exclusion Criteria: 1. A clinically significant history of gastrointestinal disorder likely to influence drug absorption. 2. Receipt of any medication with the exception of paracetamol within the 14 days prior to dosing (including topical steroids, vitamins, dietary supplements or herbal remedies). 3. Evidence of renal. hepatic, central nervous system, respiratory, cardiovascular or metabolic dysfunction. 4. Receipt of any vaccination within the previous one month. 5. Presence of infections (systemic fungal and viral infections, acute bacterial infections). 6. Current or previous history of tuberculosis. 7. A clinically significant history of previous allergy/sensitivity to hydrocortisone and/or dexamethasone. 8. Meeting any of the contraindications for Cortef® and/or dexamethasone, as detailed in the United States Prescribing Information (USPI)/Summary of Product Characteristics (SmPC), respectively 9. A clinically significant history of drug or alcohol abuse. 10. Inability to communicate well with the Investigator (i.e., language problem, poor mental development or impaired cerebral function). 11. Participation in a New Chemical Entity clinical study or a marketed drug clinical study within the previous three months, or five half- lives of the study drug, whichever is the longer period. (NB. the three-month washout period between trials is defined as the period of time elapsed between the last dose of the previous study and the first dose of the next study). 12. Subjects who have consumed more than two units of alcohol per day within seven days prior to the first dose or have consumed any alcohol within the 48-hour period prior to the first dose. 13. Donation or receipt of 450 mL of blood within the previous three months. 14. Subjects who smoke (or ex-smokers who have smoked within six months prior to first dose). This includes e-cigarette and shisha users. 15. Subjects who work shifts (i.e. regularly alternate between days, afternoons and nights).