A single dose, two treatments (Postday and Opxion), two periods, two sequences, crossover, randomized, prospective design was chosen with a washout of 21 days between the two study periods. Treatment groups were balanced with the same number of male healthy volunteers who were randomly assigned to the study drug administration sequences.

Inclusion Criteria:

• Healthy male volunteers age between 18 and 55 years old with normal vital signs, electrocardiogram (ECG), blood chemistry, liver function profile and urinalysis

Exclusion Criteria:

• History of illnesses or any organic abnormalities that could affect the results of the study.
• History of abuse tobacco or alcohol or regular use of recreational or therapeutic drugs.
• Subjects that have taken any medication within 14 days or that are in an elimination period of less than 7 half-lives (whichever is longest) before study startup.