General Information

Retin-A Micro (tretinoin) is a retinoid. The microspheres in Microsponge entrap tretinoin and formulates them into a gel. The microspheres hold the medication in reserve, allowing the skin to absorb small amounts of tretinoin over time. 

Retin-A-Micro is specifically indicated for the topical treatment of acne vulgaris.

Retin-A-Micro is supplied as a topical gel. Apply a thin layer of Retin-A Micro once daily, before bedtime, to skin where lesions occur. Keep away from eyes, mouth, nasal creases, and mucous membranes.

Mechanism of Action

Although tretinoin activates three members of the retinoic acid (RAR) nuclear receptors (RARα, RARß, and RARγ) which may act to modify gene expression, subsequent protein synthesis, and epithelial cell growth and differentiation, it has not been established whether the clinical effects of tretinoin are mediated through activation of retinoic acid receptors and/ or other mechanisms. The exact mode of action of tretinoin is unknown. Current evidence suggests that topical tretinoin decreases cohesiveness of follicular epithelial cells with decreased microcomedone formation. Additionally, tretinoin stimulates mitotic activity and increased turnover of follicular epithelial cells causing extrusion of the comedones.

Side Effects

Adverse effects associated with the use of Retin-A Micro may include, but are not limited to, the following:

• skin pain
• pruritus
• skin irritation/subcutaneous irritation
• pharyngitis
• erythema

Clinical Trial Results

In comparison studies involving approximately 700 patients, Retin-A Micro had demonstrated efficacy in the treatment of acne. In patients with sensitive skin, the unique new gel was significantly less irritating that 0.1% tretinoin cream when applies to opposite facial cheeks in a double-blind study. The lower irritancy of Retin-A Micro is believed to be attributable to the design of its vehicle containing patented Microsponge systems.