A New Formulation Containing Sunscreen (SPF-15) And 1% Metronidazole (ROSASOL Cream) In The Treatment Of Rosacea

J. K. L. Tan, MD FRCPC
Acne Research and Treatment Center, Windsor, Ontario

ABSTRACT
ROSASOL Cream is a novel topical formulation of 1% metronidazole in a vehicle containing sunscreens (SPF 15). This product has demonstrated efficacy in the treatment of inflammatory lesions, erythema, and telangiectasiae associated with rosacea.

Key Words:
metronidazole, sunscreens, inflammatory lesions, erythema, telangiectasia, rosacea

ROSASOL Cream (Stiefel Canada) was issued a Notice of Compliance by TPP – Canada in October 2000, for the treatment of inflammatory lesions (papules and pustules), erythema, and telangiectasia associated with rosacea. This new formulation combines 1% metronidazole in a cream vehicle containing the sunscreens Parsol 1789 and MCX, as well as cyclomethicone and phenyl trimethicone. The latter ingredients have been shown to reduce potential irritation associated with the use of sunscreens in rosacea patients.¹ The sunscreens were formulated to provide SPF 15.

Development was based on the importance of sun protection in the management of rosacea,^2,3 and the demonstrated efficacy of topical metronidazole (see Table 1).

Table 1: Randomized placebo-controlled trials of topical metronidazole in treatment of rosacea.
*Indicates statistical significance at 0.05 level
**A reduction in inflammatory lesions and a significant decrease in telangiectasiae were seen by week 4.
There was a significant decrease in erythema by week 8.

Mechanism of Action

Current evidence suggests that the mechanism of action of metronidazole in rosacea is via inhibition of release of neutrophil-induced inflammatory mediators such as reactive oxygen species.⁹ Parsol 1789 and MCX are broad-spectrum sunscreens that are effective in both UVB and UVA wavelengths.

Table 2: Dosage and Cost (CDN) of drugs used to treat rosacea, and of SPF 15 sunscreen. Formulary prices are from La Regie de l’assurance maladie (2001 Apr) and the Ontario Drug Benefit Formulary (2001 Mar).

Pivotal Clinical Trial

A Canadian multi-center double-blind randomized trial of 120 patients against sunscreen vehicle demonstrated that ROSASOL Cream applied twice daily was significantly more effective in the treatment of rosacea.⁴ At the end of 12 weeks of treatment, mean reductions for ROSASOL Cream (in comparison to placebo) were:

• inflammatory lesions by 70% (placebo: 23%, P = 0.005)
• erythema scores by 41% (placebo: 27%, P = 0.021)
• telangiectasia scores by 17% (placebo: 4%, P = 0.043).

ROSASOL Cream was well tolerated with the majority of patients noting a reduction in itching, dryness and stinging over the course of the 12-week study.

Adverse Effects

The 37 adverse events attributed to ROSASOL Cream in the Canadian double-blind study occurred at the site of application and consisted of stinging (13 cases), erythema (8 cases), itching (5 cases) and dryness (4 cases). All patients recovered completely without sequelae.⁴

Conclusion

ROSASOL Cream, a topical product containing 1% metronidazole with sunscreens, is efficacious and well-tolerated in treatment of rosacea. In addition to improving the inflammatory and vascular clinical manifestations of this condition, it also provides the additional benefit of photoprotection in this combined product.

References

1. Nichols K, Desai N, Lebwohl MG. Effective sunscreen ingredients and cutaneous irritation in patients with rosacea. Cutis 61(6):344–6 (1998 Jun).
2. Greaves MW. Flushing and flushing syndromes, rosacea and perioral dermatitis. In: Champion RH, Burton JL, Burns DA, Breathnach, eds. Rook/Wilkinson/Ebling Textbook of Dermatology, 6th Edition. Oxford: Blackwell Science ch 46 (1998).
3. Plewig G, Kligman AM. Acne and Rosacea. Berlin, Springer-Verlag p 433 and 439 (1993).
4. Tan JKL, Girard C, Krol A, et al. Metronidazole 1% cream with sunscreen SPF 15 in treatment of rosacea. Data on file Stiefel Canada (1999). In preparation for publication.
5. Bitar A, Bourgouin J, Dore N, et al. A Double-blind randomized study of Metronidazole (Flagyl) 1% cream in the Treatment of Acne Rosacea: A placebocontrolled study. Drug Invest 2(4):242–8 (1990).
6. Bjerke JR, Nyfors A, Austad J, et al. Metronidazole (Elyzol) 1% cream v. placebo cream in the treatment of rosacea. Clin Trials J 26(3): 187–94 (1989).
7. Bleicher PA, Charles JH, Sober AJ. Topical metronidazole therapy for rosacea. Arch Dermatol 123(5):609–14 (1987 May).
8. Gamborg Nielsen P. Treatment of rosacea with 1% metronidazole cream. A double–blind study. Br J Dermatol 108(3):327–32 (1983 Mar).
9. McLellan KJ, Noble S. Topical metronidazole: A review of its use in rosacea. Amer J Clin Dermatol 1(3):191–9 (2000 May–June).
10. Jorizzo JL, Lebwohl M, Tobey RE. The efficacy of metronidazole 1% cream once

A review of the American Academy of Dermatology’s (AAD) National Skin Cancer Screening Program indicates that middle-aged and older men are not detecting melanoma in its early stages when it is most curable because they are the least likely to perform monthly skin self-examinations or visit a dermatologist regularly.

Melanomas are characterized by the uncontrolled growth of pigment-producing cells. They may suddenly appear without warning, but can also develop from or near a mole. They can occur anywhere on the body, but are found most frequently on the upper backs of men and women, or on the calves of women.

The study included 242,374 screenings conducted between 1992 and 1994, as part of the AAD’s National Skin Cancer Screening Program*. Overall, 3,476 individuals were given a presumptive diagnosis of melanoma or possible melanoma. However, melanoma was more than three times as common among middleaged and older men than among all those screened. This group of men comprised more than 44% of patients