Insulin-like growth factor 1 - Wikipedia, the free encyclopedia
Molecular weight: 7964 Daltons.
Too big for transdermal absorption (which is how buccal administration works). You'd need a microneedle array or some other assist to get it through the skin.
4 Myths About Transdermal Drug Delivery | Articles/Archives | Drug Delivery Technology
"With the active and micropore-creating transdermal technologies, molecular size is not a limiting factor."
"A rich area of research over the past 10 to 15 years has been focused on developing transdermal technologies that utilize mechanical energy to increase the drug flux across the skin by either altering the skin barrier (primarily the stratum corneum) or increasing the energy of the drug molecules. These so-called "active" transdermal technologies include iontophoresis (which uses low voltage electrical current to drive charged drugs through the skin), electroporation (which uses short electrical pulses of high voltage to create transient aqueous pores in the skin), sonophoresis (which uses low frequency ultrasonic energy to disrupt the stratum corneum), and thermal energy (which uses heat to make the skin more permeable and to increase the energy of drug molecules).7-13 Even magnetic energy, coined magnetophoresis, has been investigated as a means to increase drug flux across the skin.14 Of these technologies, only iontophoresis has been successfully developed into a marketable product, albeit for local pain relief.
Several other iontophoretic systems are in late-stage clinical development and FDA review for systemic delivery of drugs. Sonophoretic devices and thermal patch systems are in developmental stages.
A new area of intense transdermal research and development is the development of devices that create micropores in the stratum corneum, the topmost layer of the skin that serves as the greatest barrier to drug diffusion. Such devices include microstructured arrays, sometimes called microneedles, that, when applied to the skin, painlessly create micropores in the stratum corneum without causing bleeding. These micropores offer lower resistance to drug diffusion than normal skin without micropores.15 Several companies are developing this technology and are in preclinical or early stage clinical development. Laser systems are also being developed to ablate the stratum corneum from the epidermal layer.16 As with microneedles, the ablated regions offer lower resistance to drug diffusion than non-ablated skin. One company has recently received FDA approval to market this device with a lidocaine cream."
