Topical retinoids are very important in acne treatments. Clinical experience has shown that adapalene, a new topical retinoid, has a superior cutaneous safety profile. In the guidelines of care for acne vulgaris management of our country, the combinations with adapalene gel and topical antibiotics (e.g., clindamycin nadifloxacin) are an effective acne treatment, and these combination treatments are ranked as a recommendation A. For the purpose of improvement of compliance, the mixing of ointments and/or creams is common practice. However, many of the admixtures of ointments and/or creams may lack pharmaceutical stability.
To assess the pharmaceutical stability of these mixtures after mixing, we attempted to investigate the change in the appearance and contents of adapalene, clindamycin and nadifloxacin in admixtures. As a result, no lowering of the content of adapalene was noted in any admixtute. After admixtures of adapalene and clindamycin or nadifloxacin, the contents of clindamycin or nadifloxacin were constant.