Percutaneous penetration of felbinac after application of transdermal patches: relationship with pharmacological effects in rats.

We have evaluated the percutaneous penetration of felbinac following application of topical patches using a microdialysis technique, and have examined correlations with pharmacological effects. A linear microdialysis probe with a 20-mm dialysis fibre was inserted into the skin of anaesthetized rats. Probe perfusion was started at 2.0 microL min(-1) with physiological saline and after a 60-min baseline sampling of dialysate, 0.1 mL croton oil was applied to the skin surface at a concentration of 8%, v/v. A felbinac patch was then applied to the same point 60 min thereafter and dialysate was sampled at 60-min intervals up to 300 min after patch application, for determination of concentrations of felbinac and prostaglandin (PG) E2. Analgesic effects of felbinac patches in an iodoacetateinduced osteoarthritis model and an incisional pain model were evaluated using the weight bearing method. After application of patches, felbinac penetration into the skin was rapid, maximum concentrations in the dialysates with 0.07, 0.5 and 3.5% w/w felbinac patches being 0.046+/-0.02, 0.104+/-0.06 and 0.244+/-0.2 microg mL(-1), respectively. Dermal administration of croton oil caused an increment in PGE2 levels, which was significantly decreased by 0.5 and 3.5% felbinac patches 2-5 h after application. In pharmacological studies, 3.5% felbinac patches suppressed pain-associated behaviour induced by iodoacetate injection and plantar incision. These results suggested that the transdermal patch containing 3.5% felbinac may become a useful formulation.

Molecular response to phototoxic stress of UVB-irradiated ketoprofen through arresting cell cycle in G2/M phase and inducing apoptosis.

The phototoxicity of ketoprofen (KP), a non-steroidal anti-inflammatory drug, has recently attracted considerable attention, because it is photolabile and undergoes degradation when irradiated by sunlight to induce various skin diseases. The present study shows that combination of UVB irradiation with KP induced the cytotoxicity and suppressed DNA synthesis in HaCaT cells in a concentration-dependent manner. UVB-irradiated KP inhibited the cell growth and induced G2/M cell cycle arrest by modulating the levels of cdc2, cyclin B1, Chk1, Tyr15-phosphorylated cdc2 and p21. It also provoked a striking accumulation of cyclin B1-cdc2-p21 complexes, concomitantly with an increase in the levels of Tyr15-phosphorylated cdc2 and p21 protein. The presence of KP accentuated the apoptotic response to UVB radiation in HaCaT cells as evidenced by DAPI staining. The apoptotic process was associated with activation of caspase-9, caspase-3 and cleavage of PARP, and this activation could be prevented by a specific caspase-3 inhibitor. Taken together, our results suggest that KP-photoinduced apoptosis may be a useful approach to reduce or prevent skin carcinogenesis.

Microdialysis assessment of percutaneous penetration of ketoprofen after transdermal administration to hairless rats and domestic pigs.

The study was performed to evaluate the percutaneous penetration of ketoprofen after transdermal administration using a microdialysis technique in pigs, in comparison with rats. Ketoprofen release from patches was determined by analysis of the remaining drug content after application to hairless rats and pigs. Skin and knee joint penetration of ketoprofen was tested by microdialysis, and recovery was determined by retrodialysis. Residual rates in hairless rats and pigs were 68.1 ± 1.6% and 81.7 ± 4.4%, respectively, at 10h. The average recoveries of ketoprofen over 480 min in the skin and knee joint cases were 72.0 ± 3.4% and 9.8 ± 6.2% in rats and 72.3 ± 2.5% and 57.6 ± 3.1% in pigs, respectively. In rats, ketoprofen was rapidly absorbed with transdermal administration, with C(max) values of 191.7 ± 76.2 and 35.5 ± 21.7 ng/mL and AUC(0-8h) values of 918.2 ± 577.5 and 195.9 ± 137.1 ngh/mL, respectively, for the skin and knee joint. The C(max) values for the pig were 20.9 ± 18.5 and 3.7 ± 3.0 ng/mL, with AUC(0-8h) values of 73.1 ± 69.2 and 16.1 ± 16.1 ngh/mL. Ketoprofen concentrations within skin and knee joint of non-application sites in rats and pigs were less than 0.8 ng/mL. Transdermal administration of ketoprofen significantly reduced prostaglandin E2 levels in the skin of the application site and showed a tendency for inhibition in the knee joint. We thus demonstrated that topical patches containing ketoprofen can deliver the drug through the skin and knee joint of pigs and rats via direct diffusion, and microdialysis data with the pig may be useful for the prediction of human tissue penetration of drugs with transdermal administration.

Photoinflammatory responses to UV-irradiated ketoprofen mediated by the induction of ROS generation, enhancement of cyclooxygenase-2 expression, and regulation of multiple signaling pathways.

Ketoprofen (KP) is photolabile and undergoes degradation when irradiated by sunlight, causing the development of various skin diseases. In this study, we found that UVB-irradiated KP can lead to inflammatory responses mediated by the induction of COX-2 and production of PGE(2). The ability of cells to repair UVB-induced cyclobutane pyrimidine dimers was impaired by UVB-irradiated KP, which consequently facilitated UVB-induced DNA damage to keratinocytes. The reactive oxygen species (ROS) generated by the photodegradation of KP facilitate UVB-induced inflammation and apoptosis in HaCaT cells. Elevation of the COX-2 levels was inhibited by an NADPH oxidase inhibitor and an NF-kappaB inhibitor but was largely enhanced after glutathione depletion by buthionine sulfoximine. Inhibition of ERK1/2, p38, and PI3K signaling attenuated the induction of COX-2, whereas inhibition of JNK signaling by SP600125 had very little effect. UVB-irradiated KP provoked an appreciable accumulation of pSer(15)-p53/COX-2 complexes, but this nuclear association of complexes was partially inhibited by PD98059. Silencing of COX-2 with siRNA was associated with reduced p53 phosphorylation and enhanced KP-photoinduced loss of mitochondrial membrane potential and cleavage of caspase 3 and PARP. This induction of apoptosis was prevented by N-acetylcysteine. In conclusion, this study highlights the particular inflammatory response to a photooxidative drug and suggests that KP-photoinduced inflammatory responses are predominantly attributable to induction of ROS generation and directly impair DNA repair.

Intra-articular penetration of ketoprofen and analgesic effects after topical patch application in rats.

The purpose of this study was to evaluate percutaneous penetration and pharmacological effects of ketoprofen after transdermal administration, compared to the oral route. Skin and knee joint penetration of ketoprofen was tested by a microdialysis technique in rats and in vivo recovery was determined by retrodialysis. After oral and transdermal administration of ketoprofen, dialysate was sampled at 60 min intervals up to 360 min, for determination of concentrations of ketoprofen and prostaglandin E2. Analgesic effects of ketoprofen in iodoacetate and adjuvant-induced arthritis models were evaluated using the weight bearing method. The average recoveries of ketoprofen over 360 min in the skin and knee joint were 60.2+/-3 and 15.8+/-9%, respectively. Cmax values for ketoprofen absorbed within the skin after oral and transdermal administration were 20.1+/-5 and 297.5+/-478 ng/mL, respectively, and within the knee joint, 4.4+/-0.4 and 2.7+/-0.9 ng/mL. The Cmax value for the plasma concentration of ketoprofen after oral administration was approximately 80 times higher than with the transdermal route. Both transdermal and oral administration of ketoprofen significantly decreased PGE2 production in the skin and knee joint and improved weight bearing after exposure to iodoacetate and adjuvant. These results indicate that the transdermal ketoprofen patch is a useful formulation that can deliver the drug in sufficient amounts to inhibit prostaglandin E2 production in the skin and knee joint.