Benzaclin - Clindamycin Phosphate And Benzoyl Peroxide gel
(Clindamycin Phosphate And Benzoyl Peroxide)Benzaclin - Clindamycin Phosphate And Benzoyl Peroxide gel Prescribing Information
BenzaClin Topical Gel is indicated for the topical treatment of acne vulgaris.
BenzaClin Topical Gel should be applied twice daily, morning and evening, or as directed by a physician, to affected areas after the skin is gently washed, rinsed with warm water and patted dry.
BenzaClin Topical Gel is contraindicated in those individuals who have shown hypersensitivity to any of its components or to lincomycin. It is also contraindicated in those having a history of regional enteritis, ulcerative colitis, or antibiotic-associated colitis.
During clinical trials, the most frequently reported adverse event in the BenzaClin treatment group was dry skin (12%). The table below lists local adverse events reported by at least 1% of patients in the BenzaClin and vehicle groups.
Local Adverse Events - all causalities in >/= 1% of patients | ||
|---|---|---|
BenzaClin | Vehicle | |
Application site reaction | 13 (3%) | 1 (<1%) |
Dry skin | 50 (12%) | 10 (6%) |
Pruritus | 8 (2%) | 1 (<1%) |
Peeling | 9 (2%) | - |
Erythema | 6 (1%) | 1 (<1%) |
Sunburn | 5 (1%) | - |
The actual incidence of dry skin might have been greater were it not for the use of a moisturizer in these studies.
Anaphylaxis, as well as allergic reactions leading to hospitalization, have been reported
during postmarketing use of clindamycin/benzoyl peroxide products. Because these reactions
are reported voluntarily from a population of uncertain size, it is not always possible to
reliably estimate their frequency or establish a causal relationship to drug exposure.
BenzaClin® Topical Gel contains clindamycin phosphate (7(S)-chloro-7-deoxylincomycin-2-phosphate). Clindamycin phosphate is a water soluble ester of the semi-synthetic antibiotic produced by a 7(S)-chloro-substitution of the 7(R)-hydroxyl group of the parent antibiotic lincomycin.
Chemically clindamycin phosphate is C18H34CIN2O8PS. The structural formula for clindamycin is represented below:
Clindamycin phosphate has a molecular weight of 504.97 and its chemical name is Methyl 7-chloro-6,7,8-trideoxy-6-(1-methyl-trans-4-propyl-L-2-pyrrolidinecarboxamido)-1-thio-L-threo-alpha-D-galacto-octopyranoside 2-(dihydrogen phosphate).
BenzaClin Topical Gel also contains benzoyl peroxide for topical use.
Chemically benzoyl peroxide is C14H10O4. It has the following structural formula:
Benzoyl peroxide has a molecular weight of 242.23.
Each gram of BenzaClin Topical Gel contains, as dispensed, 10 mg (1%) clindamycin as phosphate and 50 mg (5%) benzoyl peroxide in a base of carbomer, sodium hydroxide, dioctyl sodium sulfosuccinate, and purified water.
An
Benzoyl peroxide has been shown to be absorbed by the skin where it is converted to benzoic acid. Less than 2% of the dose enters systemic circulation as benzoic acid. It is suggested that the lipophilic nature of benzoyl peroxide acts to concentrate the compound into the lipid-rich sebaceous follicle.
Topical Gel was studied in male and female patients (n=13) with acne vulgaris. BenzaClin
Topical Gel (~2 g) was applied topically to the face and back twice daily for four and a half
(4.5) days. Quantifiable (>LOQ=1 ng/mL) clindamycin plasma concentrations were obtained
in six of thirteen subjects (46.2%) on Day 1 and twelve of thirteen subjects (92.3%) on Day 5.
Peak plasma concentrations (Cmax) of clindamycin ranged from 1.47 ng/mL to 2.77 ng/mL on Day 1 and 1.43 ng/mL to 7.18 ng/mL on Day 5. The AUC(0-12 h) ranged from 2.74 ng.h/mL to
12.86 ng.h/mL on Day 1 and 11.4 ng.h/mL to 69.7 ng.h/mL on Day 5.
The amount of clindamycin excreted in the urine during the 12-hour dosing interval increased
from a mean (SD) of 5745 (3130) ng on Day 1 to 12069 (7660) ng on Day 5. The mean % (SD) of
the administered dose that was excreted in the urine ranged from 0.03% (0.02) to 0.08% (0.04).
A comparison of the single (Day 1) and multiple (Day 5) dose plasma and urinary
concentrations of clindamycin indicates that there is accumulation of clindamycin following
multiple dosing of BenzaClin Topical Gel. The degree of accumulation calculated from the
plasma and urinary excretion data was ~ 2-fold.