Bioequivalence Study of Two Imiquimod Cream 5%

Inclusion Criteria: * Patients must have 4 to 8 clinically diagnosed, non-hyperkeratotic, non-hypertrophic AK lesions within a 25 cm2 contiguous treatment area on either the face or balding scalp * Women either must be 1 year post-menopausal, surgically sterile, or agree to use a medically accepted form or birth control * Free of any systemic or dermatological disorder * Any skin type or race, providing the skin pigmentation will allow discernment of erythema Exclusion Criteria: * Basal cell or squamous cell carcinoma, or other possible confounding skin conditions (on face and scalp) * History of cutaneous hyperreactivity or facial irritation to topical products * Engaging in activities involving excessive or prolonged exposure to sunlight * Receiving systemic cancer chemotherapy, psoralen plus UVA therapy, UVB therapy, laser abrasion, dermabrasion, glycolic acids, or chemical peels 6 months prior to study entry * Currently using or have used systemic steroids 2 months prior to study * Currently using or have used on the treatment area over-the-counter retinol products, corticosteroids, cryosurgery, curettage, 5-fluorouracil, or other topical actinic keratosis treatments 28 days prior to randomization * Pregnant or nursing mothers * History of allergy or sensitivity to imiquimod or related compounds or other components of the formulation * Taking immunosuppressant medication