Physicochemical study on microencapsulation of hydroxypropyl-beta-cyclodextrin in dermal preparations.
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.
Al-Rawashdeh
Nathir A F
NA
Department of Applied Chemical Sciences, Jordan University of Science and Technology, Irbid, Jordan. nathir@just.edu.jo
Al-Sadeh
Khaled S
KS
Al-Bitar
Mohammad-Bassam
MB
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*
D013473:Sunscreening Agents; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin