In vitro study on the transfer of volatile oil components.

The following volatile oils were tested in vitro: chamomile (Matricaria recutica L.), peppermint (Mentha piperita L.) and sage (Salvia officinalis L.) to obtain information on which components of volatile oils or minerals are able to pass through the membranes under different conditions. The transfer of chamomile and peppermint oil from aqueous volatile oil to the stomach (pH=1.1) and then to the plasma (pH=7.5) was studied, and the transfer of sage oil through the skin (from pH=5.5 to pH=7.5) was examined. The transfer of some components was more favorable than that of others. The transfer of chamomile oil was faster to buffer pH=1.1 than from buffer pH=1.1 to buffer pH=7.5 and most of the components, except for chamazulene, passed through the membranes. In the case of peppermint the components went through the membranes in the first 15 min although the main components mostly remained in the initial solution. The sage oil transferred showed the same characteristics as the starting oil. A small amount of metal present in the volatile oils also passed through the membranes. The transfer of metals varied, depending on the time, type of the oil, metal quality and the conditions applied.