Emerging botulinum toxins enter the cosmetic market

Key Points

Wailea, Hawaii - For the most part, it is the dose and dilution of a given botulinum toxin that differentiates it from others, according to an expert who spoke at MauiDerm 2011 in February.

Ever since Botox Cosmetic (onabotulinumtoxinA, Allergan) hit the market, it has gained enormous popularity in both the cosmetic and medical fields, and many other pharmaceutical and aesthetic companies have tried to produce additional botulinum toxins. Though Botox and Dysport (abobotulinumtoxinA, Medicis) remain the most popular, others are surfacing.

"Botulinum toxins are produced and marketed by several different companies," says Michael H. Gold, M.D., a cosmetic and dermatologic surgeon and director of Gold Skin Care Center, Tennessee Clinical Research Center and The Laser and Rejuvenation Center. He is also clinical assistant professor of dermatology, Vanderbilt University School of Medicine and School of Nursing, Nashville, Tenn. "However, the comparator is always Botox. The onset of action, the time to maximum take and the longevity of the product are all parameters that apparently differentiate toxins. However, it is all a matter of dose and dilution."

According to Dr. Gold, many physicians presume that Dysport acts faster, having an onset of action about 24 hours faster than Botox. It remains unclear, however, as to which product has a more rapid maximum take of full effect.

As for longevity of effect, most trials suggest that Botox and Dysport last about the same time, Dr. Gold says, although there are varying reports on the longevity, as one may last several weeks longer than the other, depending on the study. "I think the results of all the studies I've looked at in total are reflecting what the initial clinical trials showed; namely, Dysport works a day or so faster, they are both in full effect by day seven and they both last on average for four months."

Diffusion

The diffusion of botulinum toxin has been a long-standing issue regarding which product diffuses more than the other. A study performed by Mark Nestor, M.D., and colleagues (Nestor MS, Ablon G, Poster presented at: IMCAS; Jan. 6-9, 2011; Paris) showed there were no adverse effects of diffusion when comparing Dysport to Botox, meaning there was no diffusion effect. Hexsel et al showed there is no real massive diffusion effect with either of the products (Hexsel C, Hexsel D, Porto MD, et al. Dermatol Ther. 2011;24(1):54-61).

According to Dr. Gold, the dose and dilution of botulinum toxin is key in maximizing results while keeping adverse events to a minimum. Many physicians now are using a dilution of 2.5 units Dysport:1.0 unit Botox as the most appropriate dilution.