The purpose of this study is to study the relative bioavailability of AZD1981 when using a new tablet compared to the current tablet.

Inclusion Criteria:

• Healthy male and postmenopausal or surgically sterile female volunteers aged 18-55, inclusive
• Have a body mass index between 19-30 kg/m2 and weigh at least 50 kg and no more than 100 kg, inclusive
• Be a non-smoker or ex-smoker who has stopped smoking for >6 months prior to screening
• Volunteers must be willing to use barrier methods of contraceptive, unless their partners are post-menopausal, surgically sterile or using accepted contraceptive methods.

Exclusion Criteria:

• Any clinically significant disease or disorder
• Any clinically relevant abnormal findings in the physical examination, clinical chemistry, haematology, urinalysis, vital signs (including body temperature), or ECG assessments at Visit 1, or in vital signs (including body temperature) at Visit 2
• Prolonged QTcF >450 ms or shortened QTcF<340 ms at Visit 1 or family history of long QT syndrome
• History of, or current alcohol or drug abuse