Background: Use of topical or transdermal administration of Celecoxib (Cxb) is an interesting
strategy in cutaneous treatments since it reduces or avoids side effects of the oral route. However,
Cxb´s high lipophilicity and the stratum corneum (SC) barrier impair cutaneous penetration.
Objective: Evaluation of copaiba oil (C.O) as a potential skin penetration enhancer (P.E) for Cxb.
Methods: The chemical composition of C.O was evaluated by GC-MS. Both in-vitro release and permeability
assay of Cxb in Polyethylene glycol 400/ propylene glycol (PEG 400/PG) vehicle associated to
C.O (1-50% w/w) were determined in a modified diffusion cell fitted with a synthetic hydrophobic
membrane and pig ear skin as model, respectively.
Results: GC-MS analysis of C.O showed that it is composed of sesquiterpenes (68.65%) and diterpenes
(22.26%). Formulations containing 25% C.O (F4) and 50% C.O (F5) have shown in-vitro burst release
in the first 2 h, but only F4 released 100% of drug after 24 h. The highest Cxb permeation across skin
was obtained from F4 and the highest skin retentions for F4 and F5 in the stratum corneum and epidermis
Conclusion: The increased Cxb permeability through skin and its retention for an extended time (24h)
at 25% C.O suggest that it could be a promising adjuvant for the development of transdermal formulations