Study to Evaluate the Safety, Tolerability, and PK of Fulvestrant After IM Administration

Inclusion Criteria: * Body Mass Index (BMI) of 18 kg/m2 to 32 kg/m2 * Body weight of at least 50 kg at screening * Good health as determined by evaluations * Negative serum pregnancy test * Subjects who are naturally postmenopausal for at least 12 consecutive months with a follicle-stimulating hormone level at Screening of ≥40 mIU/mL * Subjects who are peri-menopausal and experiencing at least one of specified symptoms of menopause (eg, hot flashes, mood swings, night sweats, and others) * Negative urine test for drugs of abuse * Negative urine test for HIV antibody, HBsAG, and HCV at Screening * Women of child-bearing potential must agree to consistently practice contraception throughout the duration of the study and continue to do so for 1 year after receiving study drug by one of the following methods: abstinence, condom, diaphragm or cervical cap with spermicide, intrauterine device or male partner had previously undergone a vasectomy as declared in medical history Exclusion Criteria: * Recent history (6 months) or current evidence of any clinically significant (uncontrolled) disorder including hepatic, renal, cardiovascular, psychological, pulmonary, metabolic, endocrine, neurologic, infectious, gastrointestinal, hematologic or oncologic disease, or other medical conditions that may interfere with the subject completing the study * Lab test results outside the normal range at Screening or Day 1 considered clinically significant by the Investigator * Use of hormonal replacement therapy within 6 months prior to randomization an/or current use of oral contraceptive pill or patch as contraceptive method throughout the study * Concomitant medication that can affect bleeding * Recent history (6 months) or presence of an abnormal ECG that, in the opinion of the Investigator, is clinically significant * Subjects with QTcF interval duration \>470 milliseconds * History of alcoholism or drug addiction within 1 year prior to Day 1 * History of allergy or a known sensitivity to product components of fulvestrant Test and Reference formulations * Creatinine clearance \<60 mL/minute based on the Cockcroft-Gault equation * Blood donation of 500 mL or more or a significant loss of blood within 56 days prior to Day 1 * Previous exposure to fulvestrant * Familial relationship with another study participant