Frequently occurring skin irritancy and flare-up reactions impede the use of topical tretinoin for acne vulgaris due to poor patient compliance. Liposome encapsulation improves penetration into the skin and local tolerability in animals. We investigated efficacy and local tolerability of liposomal tretinoin in man. In a double-blind study 20 patients with uncomplicated acne vulgaris received liposomal tretinoin (0.01%) on one side of the body and a commercial gel preparation with either 0.025% or 0.05% on the other once daily for 10 weeks. Comedones and papules/pustules were counted every 2 (-4) weeks. Then also redness, scaling, and burning were rated according to a four-point scale. Moreover, the patients noted skin irritancy in a diary on a daily base. With conventional tretinoin the gels were equally efficacious and equally well tolerated. Liposomal tretinoin also appeared equipotent to the reference gels. There may even have been a slightly more rapid clearing of comedones following the liposome preparation. With respect to skin irritancy, however, liposomal tretinoin was superior. As rated by the patients, liposome encapsulated tretinoin induced less burning (mean cumulative score 2.7 +/- 1.2) than the 0.025% gel (16.1 +/- 7.1) and the 0.05% gel (9.7 +/- 4.1) gel and less erythema (1.8 +/- 0.7) than the 0.025% gel (11.4 +/- 3.8; (P < 0.05). Liposomal tretinoin was also better tolerated according to the rating by the investigator. Liposomal encapsulation of tretinoin allows reduction of the concentration of the active agent without a decline in efficacy for acne vulgaris. Since local tolerability is thus increased, liposomal tretinoin should favor the acceptance of this treatment by the patient.

The role of regular skin cleansing with soap or syndet in pre-acne is ill-defined. The intention of this study was to assess the relative value of an acidic syndet bar and a conventional soap bar in the prevention of acne lesions in acne-prone patients. In a randomized, open, comparative trial the three months' application of either an acidic syndet bar or a conventional soap to facial skin for 1 min each in the morning and in the evening was compared in 120 adolescents and young adults with inflammatory acne grade I or II according to the Plewig and Kligman classification. It was a confirmatory trial with the number of inflammatory lesions being the prime parameter of concern. In addition, non-inflammatory acne lesions were analyzed as were parameters of safety such as itching, redness and scaling. While the number of inflammatory acne lesions, i.e., papulopustules, did not differ in the two trial groups composed of 57 evaluable cases each, this was the case from 4 weeks of application onward: in the group using soap the mean number of inflammatory lesions increased from 14.6 (+/- 5.3) to 15.3 (+/- 6.0), while it decreased in the other group from 13.4 (+/- 5.2) to 10.4 (+/- 5.8) (p < 0.0001). Symptoms or signs of irritation were seen in 40.4% of individuals belonging to the former and 1.8% belonging to the latter group. The number of papulopustules characteristic of inflammatory acne thus is clearly lower when a syndet bar of the acidic type is regularly used for cleansing the face as compared to a (necessarily alkaline) soap.(ABSTRACT TRUNCATED AT 250 WORDS)