Topical Azithromycin same as Clarithromycin

Written by on December 7, 2005 in macrolides with 1 Comment

A topical azithromycin preparation for the treatment of acne vulgaris and rosacea.

Journal of Dermatological Treatment
, Volume 15, Number 5 / September 2004, Pages 295 – 302

McHugh RC, Rice A, Sangha ND, et al.

BACKGROUND: Erythromycin is a common therapy for acne and rosacea. A newer macrolide, azithromycin, offers superior tissue distribution and cellular concentration and is an effective oral anti-acne agent. Topical formulations such as erythromycin have been a major clinical therapy for acne. To date, no topical solution of azithromycin is available for the treatment of acne.

OBJECTIVE: To prepare a stable topical 2% azithromycin formulation that could be used in an acne clinical trial to determine the efficacy of topical azithromycin in treating subjects with acne vulgaris and acne rosacea.

METHODS: The study was divided into two phases. In phase I, azithromycin was prepared over a range of ethanol/water concentrations to determine solubility. The stability of a 2% azithromycin in 60% ethanol/water preparation was assessed by high-pressure liquid chromatography. The temperature, light, and pH dependence of the stability was also assessed. In phase II, a single center, randomized, double-blind, treatment-controlled study compared once-nightly application of topical 2% azithromycin versus 2% erythromycin. A total of 20 subjects with moderate inflammatory acne and 20 with rosacea were examined clinically at 0, 2, 4, 8, and 12 weeks for a 12-week period. Efficacy was evaluated with the Physician’s Visual Analog Scale evaluation (PVAS), the papulopustule count, and acne severity rating (in subjects with acne).

RESULTS: In phase I, azithromycin was soluble in 60% ethanol/water. A 2% azithromycin in 60% ethanol/water solution maintained stability at room temperature for up to 26 weeks but at 37°C there was some decay (16%) at 26 weeks. The stability was greatest at pH 6.8 and was unaffected by ambient light exposure. In phase II, the number of inflammatory lesions decreased in both acne and rosacea subjects treated with 2% erythromycin (7.56, p=0.03 and 4.4, p=0.01, respectively). Azithromycin was not as effective for the treatment of rosacea. Both azithromycin (p=0.01) and erythromycin (p=0.03) treatment significantly reduced the inflammatory lesion count in acne vulgaris. No significant adverse events were identified in the acne group. In patients with rosacea, transient irritation occurred in five patients.

CONCLUSIONS: A 2% azithromycin in 60% ethanol/water solution can be prepared and is stable for at least 6 months at room temperature. The methodology and power of the study were adequate to identify improvement in acne vulgaris and rosacea. Though it appears the formulation of topical azithromycin was at least comparable with topical erythromycin, larger studies would be needed to determine whether topical azithromycin has any significant advantage over topical erythromycin.

Keywords: Acne Vulgaris, Azithromycin, Erythromycin, Randomized Trial, Rosacea, Topical Antibiotics

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About the Author: David Pascoe started the Rosacea Support Group in October 1998. .

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1 Reader Comment

  1. David Hahn says:


    Alot of en someone gets acne, an infection etc….. it may be a various
    assortment of gram + (or-) becteria, fungus, mildew, acne and hundreds of other germs or viruses.
    THE COMBINATION IS CURRENTLY UNKNOWN, (HOWEVER), it seems that the following (in some sort of partially soluble mixture, may be:

    Hydrogen Peroxide (3%) EXCESS SOLUTE AS NORMAL H2O2 (WATER)
    Ethanol alcohal (2-30%)
    Vinegar(Acetic acid 5%) (REQUIRED BORAX / MINUTE AMOUNTS!
    Salicylic acid (.2% to 1%)
    Dissolved Erythromycin and or Azithromycin (small amounts).

    This combination (UNKNOWN PERCENTAGES) should kill most acne, mold,
    mildew, fungus, , bacteria (gram+ and gram -), infections,


    Mr. Hahn Former USN/USMC (RET.), EAGLE SCOUT/ Time Travel Institute Member/
    associates of applied science/ associates of communication (P.A. / M.C.C. College)

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