Enhancing effects of myristyl lactate and lauryl lactate on percutaneous absorption of indomethacin in rats

The enhancing effects of myristyl lactate (ML) and lauryl lactate (LL) on the percutaneous absorption of indomethacin (ID) from test solutions in propylene glycol (PG) were investigated in rats. ID absorption was observed to be markedly enhanced by the addition of ML or LL to PG as compared with the control (PG alone). The marked enhancing effects were observed at concentrations greater than 3% ML and 3% LL in PG. In particular, the maximal enhancement of percutaneous absorption of ID was achieved at 5% ML and LL. To elucidate the mode of action of ML as an enhancer, the percutaneous absorption of ID through the skin pretreated with ML alone was investigated. It was suggested that ML acts on the stratum corneum to produce its effect.