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Duac na pryszcze - Skuteczne rozwiązanie dla piękniejszej skóry
Duac - Clinical Pharmacology
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12.1 Mechanism of Action
Clindamycin is a lincosamide antibacterial [see Clinical Pharmacology (12.4)].
Benzoyl peroxide is an oxidizing agent with bacteriocidal and keratolytic effects, but the precise mechanism of action is unknown.
12.3 Pharmacokinetics
A comparative trial of the pharmacokinetics of DUAC Gel and 1% clindamycin solution alone in 78 subjects indicated that mean plasma clindamycin levels during the 4-week dosing period were less than 0.5 ng per mL for both treatment groups.
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.
12.4 Microbiology
Clindamycin binds to the 50S ribosomal subunits of susceptible bacteria and prevents elongation of peptide chains by interfering with peptidyl transfer, thereby suppressing protein synthesis.
In Vivo Activity
No microbiology studies were conducted in the clinical trials with this product.
In Vitro Activity
The clindamycin and benzoyl peroxide components individually have been shown to have in vitro activity against Propionibacterium acnes , an organism which has been associated with acne vulgaris, however, the clinical significance of this in vitro activity is not known.
There are reports of an increase of P. acnes resistance to clindamycin in the treatment of acne. In patients with P. acnes resistant to clindamycin, the clindamycin component may provide no additional benefit beyond benzoyl peroxide alone.
Drug Interactions
7.1 Erythromycin
Avoid using DUAC Gel in combination with erythromycin-containing products due to its clindamycin component. In vitro studies have shown antagonism between erythromycin and clindamycin. The clinical significance of this in vitro antagonism is not known.
7.2 Concomitant Topical Medications
Concomitant topical acne therapies should be used with caution since a possible cumulative irritancy effect may occur, especially with the use of peeling, desquamating, or abrasive agents. If irritancy or dermatitis occurs, reduce frequency of application or temporarily interrupt treatment and resume once the irritation subsides. Treatment should be discontinued if the irritation persists.
7.3 Neuromuscular Blocking Agents
Clindamycin has been shown to have neuromuscular blocking properties that may enhance the action of other neuromuscular blocking agents. DUAC Gel should be used with caution in patients receiving such agents.
7.4 Topical Sulfone Products
Use of topical benzoyl-peroxide-containing preparations with topical sulfone products may cause skin and facial hair to temporarily change color (yellow/orange).
Duac gel sastav
Kada je u pitanju potpuna lista sastojaka bitno je videti šta sve sadrži. U pitanju je lek i nakon nanošenja, naša koža ga apsorbuje.
Pored aktivnih sastojaka a to su klindamicin i benzoil peroksid, celokupna lista sastojaka izgleda ovako:
Karbomer, Dimetikon, Dinatrijum-laurilsulfosukcinat, Dinatrijum-edetat, Glicerol, Silicijum-dioksid, Poloksamer 182, Voda, Natrijum-hidroksid.
Iz ove liste izdvajamo dobre sastojke, a to su:
- Glicerol – tj. glicerin je dobar sastojak jer je u pitanju ovlaživač pa kožu hidrira.
- Silicijum-dioksid – koristi se za skupljanje masnoće i viška sebuma sa kože.
- Poloksamer 182 – ovaj sastojak daje koži mekan i gladak izgled.
- Natrijum-hidroksid – još jedan siguran sastojak koji se u kozmetici koristi za regulisanje PH vrednosti između proizvoda i kože.
Sastojci koji nisu poželjni su sledeći:
- Dimetikon – silikon koji se nalazi u Duac gelu. Silikoni nisu poželjni sastojak u proizvodima za negu.
- Dinatrijum-laurilsulfosukcinat – surfikant koji se u kozmetici koristi za čišćenje kože, ali može da izazove iritacije očiju i sluzokože.
Duac Description
DUAC (clindamycin phosphate and benzoyl peroxide) Gel, 1.2%/5% is a fixed combination product with two active ingredients in a white to slightly yellow, opaque, aqueous gel formulation.
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.
Clindamycin phosphate is C 18 H 34 ClN 2 O 8 PS. The structural formula for clindamycin phosphate 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 -α-D- galacto -octopyranoside 2-(dihydrogen phosphate).
Benzoyl peroxide is C 14 H 10 O 4 . It has the following structural formula:
Benzoyl peroxide has a molecular weight of 242.23.
Each gram of DUAC Gel contains 10 mg (1%) clindamycin, as clindamycin phosphate, and 50 mg (5%) benzoyl peroxide in a base consisting of carbomer homopolymer (type C), dimethicone, disodium lauryl sulfosuccinate, edetate disodium, glycerin, methylparaben, poloxamer 182, purified water, silicon dioxide, and sodium hydroxide.
