On 17 Jan 2005 06:44:54 -0800, (jannis) wrote:

Hi everybody,

I am new to this forum. I would like to ask you if you know of any
plant or herb extract that has the power to dilate the pores of the
human skin, thus making the epidermis more permeable (by topical
application that is). Thanks in advance.

Jannis

Your skin has evolved to be very effective at stopping whatever it is
you are proposing to do, so this is a big deal in transdermal drug
delivery research, where products that can do this are called
penetration enhancers.

The stratum corneum, which is the exposed layer of dead skin cells, is
the main barrier. There are three ways to cross this barrier:
transcellular (through the s.c. cells), intercellular (through the
space between s.c. cells), and follicular (through hair follicles and
pores).

Transcellular penetration is not very effective, because anything you
are trying to get across the skin must pass through several layers of
cells.

Follicular penetration enhancers, which it sounds like you are
interested in, are actually not much used, because the surface area
that can be made available is really very small, something like 1/1000
of the skin area.

Intercellular penetration enhancers are the most common and best
researched. Water, or any product that enhances skin hydration, is at
least as good as anything else (unless you're trying to move something
that isn't water-soluble). Any botanical containing alpha-hydroxy
acids, essential fatty acids, or menthol and its relatives is worth
considering as a penetration enhancer, and there is much current
interest in approaches to screening these for effectiveness and
toxicity.

--
Chris Green