We focus on small molecules (low molecular weight) with serious side-effects that result from the passage through the gastrointestinal tract.
Based on the existing patch technologies, many small molecules cannot pass the skin and require a different route of administration. At present, there are only some 20 to 30 drug molecules delivered by transdermal patches on the market. These patches are highly inefficient. Up to 50 to 95% of the active ingredient (e.g., steroidal hormones and opiates) remains behind in the patch and does not enter the body.
Moreover, it takes between 6 and 12 hours with existing pharmaceutical patches to observe a clinical effect after application of the patch onto the skin, simply because of the barrier effect of the stratum corneum. Hence an onset (rapid) mode of action is impossible with existing patches.
Microneedles allow to overcome the barrier of the stratum corneum and allow for a much quicker mode of action, if required. Integration of micro-needle technology into patches allows to strongly increase the ratio of delivered vs. undelivered dose and makes it possible to administer certain drugs which cannot be delivered with the existing transdermal patch technologies. By reformulating oral drugs into transdermal (microneedle) administration forms, the first pass effect (liver) is eliminated.