title: Physicochemical study on microencapsulation of hydroxypropyl-beta-cyclodextrin in dermal preparations.
abstract: OBJECTIVE
  To investigate the effect of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) concentration on the physicochemical properties of the sunscreen agents, namely oxybenzone (Oxy), octocrylene (Oct), and ethylhexyl-methoxy-cinnamate (Cin), in aqueous solution and cream formulations.
  
  
  METHODS
  The inclusion complexes of sunscreen agents with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) in aqueous solution and solid phase were studied by UV-vis spectrophotmetery, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and 13C-NMR techniques. The photodegradation reaction of the sunscreen agents' molecules in lotion was explored using UV-vis spectrophotometry and high-performance liquid chromatography (HPLC).
  
  
  RESULTS
  The formation of the inclusion complexes was confirmed experimentally using DSC, SEM, and 13C-NMR. The results of spectrophotometric and HPLC studies have shown that the inclusion complexation with HP-beta-CD has the potential to enhance the photostability of the selected sunscreen agents in lotion. HPLC results indicated that HP-beta-CD has approximately increases the photostability of Oct by six- to eightfold. Moreover, the presence of HP-beta-CD in lotion controlled the isomerization process of Cin to a certain degree, which was found to be a function of the amount of HP-beta-CD added.
  
  
  CONCLUSIONS
  It has been demonstrated that the photostability of the tested sunscreen agents has been enhanced upon forming inclusion complexes with HP-beta-CD in lotion. The results of this study demonstrate that HP-beta-CD can be utilized as photostabilizer additive for enhancing the photostability of the sunscreen agents' molecules.
authors.affiliation: Department of Applied Chemical Sciences, Jordan University of Science and Technology, Irbid, Jordan. nathir@just.edu.jo
authors.forename: Nathir A F
authors.initials: NA
authors.lastname: Al-Rawashdeh
authors.forename: Khaled S
authors.initials: KS
authors.lastname: Al-Sadeh
authors.forename: Mohammad-Bassam
authors.initials: MB
authors.lastname: Al-Bitar
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D000279:Administration, Cutaneous; D055598:Chemical Phenomena; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D004339:Drug Compounding / Q000379:methods; D013473:Sunscreening Agents / Q000008:administration & dosage / Q000138:chemical synthesis*; D047392:beta-Cyclodextrins / Q000008:administration & dosage / Q000138:chemical synthesis*
chemical_list: D013473:Sunscreening Agents; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin