caplets, liquids, creams, ointments. They produce the “recipes” for the drugs.
the right dose at the right time so it can do its job.
Targeted drug delivery
medication in some parts of the body and even some cells relative to others.
Largely founded on nanomedicine, which plans to employ nanoparticle-mediated drug delivery
in order to combat the downfalls of conventional drug delivery
We can make nano-sized drug delivery carriers so the drug is trapped within particles that are
100-200 nanometers in dimension.
For wound care, we need lipid-based nanocarriers.
Application: Topical antiseptics
Increased effectiveness of the skin antiseptics should ultimately decrease the use of antibiotics.
Topical antiseptics are preferable to antibiotics because less likely to induce resistance, owing to
their unspecific mode of action and the high concentrations in which they can be used.
Topical antiseptics can prevent biofilm build-up as well as antimicrobial action.
Challenge: unknown depth of penetration and unknown effective concentration
Transdermal delivery routes: 3 pathways
The paracellular path: tortuous route through the membrane
The transcellular path
The transappendageal path: follicular route
encompass only 1% of total skin area, and also varies per individual depending on follicle density
and size. Other factors that affect transport ability of transappendageal pathway are other fill
materials, such as sebum and desquamated cells, in addition to cultural habits and weather
conditions (sweat, deodorant, etc.)
Microorganisms reside both on the skin surface as well as in hair follicles and lower skin depths.
Endogenous infections arise from endoflora from skin, mucous membranes and hollow viscera,
seeding from another infection. Follicles also present a unique microbial niche for
microorganisms within the skin.
When the barrier is breached, commensal microoganisms may therefore persist at the site.
Therefore, effective and rapid permeation of the antimicrobial into the deeper layers of the skin
may prevent infection.
Our goal: Try and increase how much drugs penetrate into the skin and influence where
skin penetration enhancers by
increasing drug partitioning into the skin (solvent effect)
enhancing drug diffusion
reversibly disrupting lipid bilayers
evaporation of terpenes like alcohol
Skin permeation studies are done by putting the formulation to be tested on top of a skin
sample (varying depths) and then measuring below what penetrated at what depth.
It seemingly did not work as well as crude oil for penetration effectiveness, however.
Olive oil, however, did not work as well as eucalyptus oil in permeation studies.
Nanotechnology and targeting
release and preferential targeting.
Unique size dependent properties of lipid nanoparticles offer possibilities for delivery of drug for
both controlled release and site specific drug delivery.
Control of particle size and surface properties determines how delivery system interacts with
Triclosan is difficult to work with. It doesn’t dissolve in water, BUT it does form well into a lipid
nanoparticle. We can get more triclosan into the skin by forming it into nanoparticles.
high shear homogenization > hot pre-emulsion > ultrasonication > hot nanoemulsion > solid lipid
When emulsion particle size is decreased to the nano level, it becomes clear (no longer diffuses
light) and you can get a nice, even particle size distribution.
Much higher percentage of triclosan retained in skin when delivered by nanoparticles.
Also increases skin penetration.
We’ve tried incorporating chlorhexidine into Altrazeal gels in saline – what happens?
Where we are now with this work
Successful formulation of potentially synergistic combination of ingredients into
release of CHG
distributed to any third party by the recipient for commercial purposes without the expressed written consent of EHP
Inc. Furthermore, the recipient may only use these notes for personal and not commercial use. In addition, if the
recipient does distribute these notes to a third party for personal use, the recipient agrees to not alter or in any way
modify this statement of proprietary rights. All recipients of these notes agree to hold EHP Inc., dba IPIP, its
subsidiaries, agents, servants, and employees harmless for any liability arising from the use of said notes.