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Pacnex MX

Generic name: benzoyl peroxide
Dosage form: topical solution
Drug class: Topical acne agents

Medically reviewed by Last updated on Oct 22, 2020.

Disclaimer: This drug has not been found by FDA to be safe and effective, and this labeling has not been approved by FDA. For further information about unapproved drugs, click here.

DESCRIPTION:Pacnex (4.25% Benzoyl Peroxide) MX is intended for topical adminstration and contains Benzoyl Peroxide for use in the treatment of acne vulgaris. Benzoyl Peroxide is an oxidizing agent that possesses antibacterial properties and is classified as a keratolytic.

CLINICAL PHARMACOLOGY: The mechanism of action of Benzoyl Peroxide is not totally understood but its antibacterial activity against Propionibacterium acnes is thought to be a major mode of action. In addition, patients treated with Benzoyl Peroxide show a reduction in lipids and free fatty acids, and mild desquamation (drying of and peeling activity) with simultaneous reduction in comedones and acne lesions. Little is known about the percutaneous penetration, metabolism, and excretion of Benzoyl Peroxide, although it has been shown that Benzoyl Peroxide absorded by the skin is metabolized to benzoic acid and then excreted as benzoate in the urine. There in no evidence of systemic toxicity caused by Benzoyl Peroxide in humans.

INDICATIONS AND USAGE: Pacnex (4.25% Benzoyl Peroxide) MX is indicated for the topical treatment of acne vulgaris.

CONTRAINDICATIONS: These preparations are contraindicated in patients with a history of hypersensitivity to any of their components.

WARNINGS: When using this product, avoid unnecessary sun exposure and use a sunscreen.

PRECAUTIONS: General: For external use only. If severe irritation develops, discontinue use and institute appropriate therapy. After reaction clears, treatment may often be resumed with less frequent application. These preparations should not be used in or near the eyes or on mucous membranes.

Information for patients: Avoid contact with eyes, eyelids, lips and mucous membranes. If accidental contact occurs, rinse with water. Contact with any colored material (including hair and fabric) may result in bleaching or discoloration. If excessive irritation develops, discontinue use and consult your physician.

Carcinogenesis, Mutagenesis, Impairment of Fertility: Data from several studies employing a strain of mice that is highly susceptible to developing cancer suggest that Benzoyl Peroxide acts as a tumor promoter. The clinical significance of these findings to humans is unknown. Benzoyl Peroxide has not been found to be mutagenic (Ames Test) and there are no published data indicating it impairs fertility.

Pregnancy: Teratogenic Effects:Pregnancy Category C: Animal reproduction studies have not been conducted with Benzoyl Peroxide. It is not known whether Benzoyl Peroxide can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Benzoyl Peroxide should be used by pregnant woman only if clearly needed. There are no available data on the effect of Benzoyl Peroxide on the later growth, development and functional maturation of the unborn child.

Nursing Mothers: It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Benzoyl Peroxide is administered to a nursing woman.

Pediatric Use: Safety and effectiveness in children have not been established.

ADVERSE REACTIONS: Allergic contact dermatitis and dryness have been reported with topical Benzoyl Peroxide therapy.

OVERDOSAGE: If excessive scaling, erythema or edema occurs, the use of this preparation should be discontinued. To hasten resolution of the adverse effects, cool compresses may be used. After symptoms and signs subside, a reduced dosage schedule may be cautiously tried if the reaction is judged to be due to excessive use and not allergenicity.


Pacnex (4.25% Benzoyl Peroxide) MX: Apply to affected areas once or twice a day, or as directed by your physician. Wet skin and liberally apply to areas to be cleansed. Massage gently into skin for 10-20 seconds, working into a full lather. Rinse thoroughly and pat dry. If excessive drying occurs, control by rinsing off cleanser sooner or using less often.


Pacnex (4.25% Benzoyl Peroxide) MX is supplied in a 16oz bottle, NDC 43538-120-16.

Store at controlled room temperature 15°-30°C (59°-86°F). Protect from freezing.


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benzoyl peroxide solution
Product Information
Product Type HUMAN PRESCRIPTION DRUG LABEL Item Code (Source) NDC:43538-120
Route of Administration TOPICAL DEA Schedule
Active Ingredient/Active Moiety
Ingredient Name Basis of Strength Strength
Benzoyl Peroxide (Benzoyl Peroxide) Benzoyl Peroxide 42.5 mg in 1 g
Inactive Ingredients
Ingredient Name Strength
Cetyl Alcohol
Edetate Disodium
Magnesium Aluminum Silicate
Propylene Glycol
Xanthan Gum
# Item Code Package Description
1 NDC:43538-120-16 1 BOTTLE (BOTTLE) in 1 CARTON
1 497.66 g in 1 BOTTLE
2 NDC:43538-120-99 12 g in 1 BOTTLE
Marketing Information
Marketing Category Application Number or Monograph Citation Marketing Start Date Marketing End Date
unapproved other 11/19/2009
Labeler - Medimetriks Pharmaceuticals inc. (019903816)
Registrant - Groupe Parima inc. (252437850)
Name Address ID/FEI Operations
Groupe Parima inc. 252437850 manufacture
Medimetriks Pharmaceuticals inc.

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