Dermal cell damage induced by topical application of non-steroidal anti-inflammatory drugs is suppressed by trehalose co-lyophilization in ex vivo analysis

Abstract

Topical administration of non-steroidal anti-inflammatory drugs (NSAIDs) is generally considered safer than oral administration, although the former can occasionally induce cutaneous irritation. We hypothesized that the cutaneous irritation by topical NSAIDs might be suppressed by trehalose, which has protective effects on biological membranes. Using the three-dimensional cultured human skin model, Living Skin Equivalent-high, we found that cutaneous damage due to NSAIDs was reduced by concomitant use of trehalose and that this effect of trehalose was reinforced by co-lyophilization of NSAIDs with trehalose. The anti-inflammatory effect of co-lyophilized NSAIDs with trehalose was comparable to that seen with NSAIDs alone in a rat model. Our results suggest that co-lyophilization of NSAIDs with trehalose might be a novel procedure that can help prevent NSAIDs-induced skin irritation.

Fig. 1.

Effects of co-lyophilization with trehalose on cytotoxicity induced by NSAIDs in LSE-high. LSE-high was treated with hydrophilic ointment containing saline, trehalose, a single NSAID an NSAID mixed with trehalose or an NSAID co-lyophilized with trehalose. The NSAIDs were: 1% (w/w) indomethacin (Ind); 1% (w/w) diclofenac (Dic); 3% (w/w) ibuprofen (Ibu); and 3% (w/w) piroxicam (Pir). Cell viability was evaluated by measuring the absorbance at 570 nm of extracts from drug- and saline-treated LSE-high. Data are presented as the mean ± SD; n=4 in each group. *P<0.05, **P<0.01, ***P<0.005, *****P<0.0005 and ******P<0.0001 compared with the vehicle group (ANOVA); †††P<0.005, ††††P<0.001, †††††P<0.0005 and ††††††P<0.0001 compared with the NSAID group (ANOVA); and ^§§§P<0.005 compared with the mixed NSAID/trehalose group (ANOVA).

Fig. 2.

Comparison of the anti-inflammatory effects of co-lyophilized NSAID/trehalose and NSAID in topical applications using a carrageenan-induced paw edema model. Hydrophilic ointments containing diclofenac or co-lyophilized diclofenac/trehalose were topically applied to the footpads of carrageenan-treated rats. The inhibition rate of paw edema was calculated from an increase in paw volume in the drug-treated groups and compared with that in the vehicle group. n=6 in the vehicle group. n=6 in the diclofenac group. n=7 in the co-lyophilized diclofenac/trehalose group. Data are presented as the mean ± SD.