Improved tretinoin photostability in a topical nanomedicine replacing original liquid suspension with spray-dried powder with no loss of effectiveness.
OBJECTIVE
The use of spray-dried powders containing tretinoin-loaded nanocapsules instead of the original liquid suspension, aimed at the preparation of dermatological nanomedicines with improved photostability, was investigated.


METHODS
Powders were prepared using lactose as a drying adjuvant. Hydrogels were prepared using two approaches: dispersing Carbopol Ultrez 10 in an aqueous redispersion of the powder or incorporating the powder in previously formed hydrogels.


CONCLUSIONS
The photodegradation of tretinoin in hydrogels prepared with the powders showed similar half-life times (around 19.5 h) compared to preparations with the original liquid nanocapsules (20.7 ± 1.4 h), regardless of the preparation approach. In addition, the topical nanomedicines prepared with the spray-dried powders presented a significant improvement in tretinoin photostability compared to the formulation containing the non-encapsulated drug.


CONCLUSIONS
This study verified that the addition of the spray-dried powders containing tretinoin-loaded lipid-core nanocapsules to hydrogels did not influence the photoprotection of the drug compared with the preparation procedure using the original liquid suspension.
Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil.
M C L
MC
Marchiori
R H
RH
Rascovetzki
A F
AF
Ourique
L A
LA
Rigo
C B
CB
Silva
R C R
RC
Beck
D000287:Administration, Topical; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000737:chemistry / Q000528:radiation effects; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D003890:Desiccation; D004337:Drug Carriers; D004339:Drug Compounding / Q000379:methods*; D004355:Drug Stability; D006207:Half-Life; D050997:Nanomedicine; D054118:Nanospheres / Q000737:chemistry*; D010316:Particle Size; D010782:Photolysis; D011108:Polymers; D011208:Powders; D013535:Suspensions; D013678:Technology, Pharmaceutical / Q000379:methods; D014212:Tretinoin / Q000008:administration & dosage* / Q000737:chemistry / Q000528:radiation effects; D014466:Ultraviolet Rays
D000970:Antineoplastic Agents; D004337:Drug Carriers; D011108:Polymers; D011208:Powders; D013535:Suspensions; D014212:Tretinoin