title: Clinical study of a retinoic acid-loaded microneedle patch for seborrheic keratosis or senile lentigo.
abstract: OBJECTIVE
  Pigmented lesions such as of seborrheic keratosis and senile lentigo, which are commonly seen on skin of people>50years of age, are considered unattractive and disfiguring because of their negative psychological impact. Drug therapy using all-trans retinoic acid (ATRA) is an attractive option for self-treatment at home. We have developed an ATRA-loaded microneedle patch (ATRA-MN) and confirmed the pharmacological effects of ATRA-MN application in mice. Here, we describe a clinical study to evaluate the safety and efficacy of ATRA-MN in subjects with seborrheic keratosis or senile lentigo.
  
  
  METHODS
  ATRA-MN was applied to the lesion site of each subject for 6h once per week for 4weeks. The skin irritation reaction was scored to assess adverse reactions and blood tests were performed to evaluate the presence of systemic adverse reactions. To assess the treatment effect using ATRA-MN, the desquamation and whitening ability of the investigational skin was observed.
  
  
  RESULTS
  Desquamation of the stratum corneum was observed following four ATRA-MN applications at 1-week intervals, but ATRA-MN applications did not induce severe local or systemic adverse effects.
  
  
  CONCLUSIONS
  These results showed that ATRA-MN treatment is promising as a safe and effective therapy for seborrheic keratosis and senile lentigo.
authors.affiliation: Laboratory of Biotechnology and Therapeutics, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Hirobe
authors.affiliation: Laboratory of Biotechnology and Therapeutics, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Risa
authors.initials: R
authors.lastname: Otsuka
authors.affiliation: Department of Dermatology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8522, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Iioka
authors.affiliation: CosMED Pharmaceutical Co. Ltd., 32 Higashikujokawanishi-cho, Minami-ku, Kyoto 601-8014, Japan.
authors.forename: Ying-Shu
authors.initials: YS
authors.lastname: Quan
authors.affiliation: CosMED Pharmaceutical Co. Ltd., 32 Higashikujokawanishi-cho, Minami-ku, Kyoto 601-8014, Japan.
authors.forename: Fumio
authors.initials: F
authors.lastname: Kamiyama
authors.affiliation: Department of Dermatology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8522, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Asada
authors.affiliation: Laboratory of Biotechnology and Therapeutics, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan. Electronic address: okada@phs.osaka-u.ac.jp.
authors.forename: Naoki
authors.initials: N
authors.lastname: Okada
authors.affiliation: Laboratory of Biotechnology and Therapeutics, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan. Electronic address: nakagawa@phs.osaka-u.ac.jp.
authors.forename: Shinsaku
authors.initials: S
authors.lastname: Nakagawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007641:Keratolytic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D017492:Keratosis, Seborrheic / Q000188:drug therapy* / Q000473:pathology; D007911:Lentigo / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009339:Needles; D012867:Skin / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D057968:Transdermal Patch / Q000009:adverse effects; D014212:Tretinoin / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D007641:Keratolytic Agents; D014212:Tretinoin
keywords: All-trans retinoic acid; Clinical study; Microneedle; Seborrheic keratosis; Senile lentigo