OK the title is a bit of a stretch as currently there is no such product as Metrofoam, but keep reading to see where I’m coming from.
Last year a patent surfaced, owned by Galderma, claiming rights to a “stable, metronidazole-based oil-in-water emulsion expandable into a topically applicable foam having a firm, creamy and light consistency” and is claimed to have improved release-penetration capacity.
This just published paper further develops the claim of increased efficacy of metronidazole foam.
The researchers claim that the emulsion form of metronidazole was able to result in complete relief of telangiectasia for 38% of patients and 50% from erythema. Metrogel does not typically help telangiectasia and has only minimal benefit for the redness of rosacea.
Only 17% of patients achieved complete relief from papules and pustules though.
The foam version of metronidazole released the active ingredient at a slower rate compared to Metrogel.
Galderma Owns metrofoam.com Domain Name
Galderma have owned the domain name metrofoam.com and trademark since 2004, which currently just redirects to Galderma.com.
Contrarian Research
Past research seems to suggest that it matters little whether you use Metrogel, Metrolotion, Metrocream or Noritate. Further it seems to not matter whether you use these products once or twice per day.
Why Does Foam Work Better ?
The conclusions tells us that “In the present study, it is estimated that metronidazole distributed in the outer oil phase of the system during preparation of the microemulsion easily penetrated the stratum corneum immediately after contact with skin.
The components also had penetration enhancing effects after the microemulsion was applied to the skin. Furthermore, the water droplets could directly enter the stratum corneum (without droplet fusion), thereby transporting metronidazole.”
Published Abstract
Chem Pharm Bull (Tokyo). 2012;60(5):583-92., Tirnaksiz F, Kayiş A, Celebi N, Adişen E, Erel A., Department of Pharmaceutical Technology, Faculty of Pharmacy, Gazi University.
The aim of this study was to prepare a topical water-in-oil type microemulsion containing metronidazole and to compare its effectiveness with a commercial gel product in the treatment of rosacea.
A pseudo-ternary phase diagram (Km=2 : 1) was constructed using lecithin/butanol/isopropyl myristate/water. The microemulsion was chosen from the microemulsion region in the phase diagram.
The formulation was a water-in-oil type microemulsion (droplet size: 11.6 nm, viscosity: 457.3 mPa·s, conductivity: 1.5 µs/cm, turbidity: 6.89 NTU) and the addition of the metronidazole did not alter the properties of the system.
The release experiment showed that the release rate of metronidazole from the commercial gel product was higher than that of the microemulsion.
Stability experiments showed that the metronidazole microemulsion remained stable for at least 6 months; none of the characteristic properties of the microemulsion had changed, the system retained its clarity and there was no sign that crystallization of metronidazole has occurred.
Microemulsion was compared to a gel product in a randomized, double-blind, baseline-controlled, split-face clinical trial for the treatment of patients.
After the 6-week treatment period there was a statistically significant difference in reduction of the main symptoms of rosacea.
Of the patients treated with the microemulsion, 17% experienced complete relief from inflammatory lesions, and 50% from erythema.
The microemulsion resulted in complete relief in 38% of the patients with telangiectasia while the commercial product did not provide any relief of telangiectasia symptoms.
In conclusion, the microemulsion containing metronidazole was found to be more effective in reducing the symptoms of rosacea compared to the commercial gel product.
See also the Full Article PDF.
A part of the study was presented as a poster at the 29th International Symposium of the Controlled Release Society (22–25
July, Seoul, 2002)
