WavePharma’s WP-chitosan is a new biomaterial. While chitosan-based, the proprietary WP-chitosan differs chemically and physically from untreated chitosan. The new material exhibits novel, useful properties that include longer and stronger bonding of active agents to the skin; complementary release of bonded agents in a controlled and programmed manner; adjustable water retention, viscosity, and pH; availability in liquids, gels, films, shaped structures and nanoparticles; and safety. WP-chitosan’s synthesis employs stable chemistry throughout and uses abundant, sustainable, and relatively low cost materials.
Chitosan is an abundant, naturally-occurring material. In its untreated form, chitosan is widely used in skin care, hair care, and other personal care products.
Untreated chitosan provides a number of useful qualities. It is by nature adhesive, antibacterial/antifungal, hemostatic, humectant and biodegradable.
The personal care products industry exploits these properties in moisturizers, emollients, film formers, hair conditioners, and in many other formulations.
WP-chitosan shares the properties of untreated chitosan, but offers much more.
WP-chitosan formulations have significant advantages over untreated chitosan and other competitive technologies. The adhesive and bonding strengths of the proprietary chitosan are superior.
Drugs, cosmeceuticals, and other active ingredients can be retained on skin, hair, and nails for prolonged periods and then can be released in a controlled, programmed manner. This, in turn, provides improved delivery and bioavailability of the retained actives.
WP-chitosan’s utility can be further enhanced by selectively altering several of its properties. These include its water retention, viscosity, and pH.
Proposed WP-chitosan applications and product innovations include:
- Vehicle for enhanced retention and release of topically applied skin care materials and pharmaceuticals.
- Potent skin moisturizer utilizing WP-chitosan’s humectant properties, its film forming capacity (to limit transdermal moisture loss); its durable bonding to skin; and its facility for chemically attaching additional humectant agents.
- Fragrance extender for use with personal care products including deodorants, soaps, shampoos, lotions, topical drug formulations, etc.
- Prevention of product preservatives’ (e.g. parabens and chloroacetamides) access to the vascular bed beneath the skin.
- Topical film former applied to reduce facial wrinkles.
- Durable, stable, skin filler and bulker.
- Persistent hair moisturizer, conditioner, and scalp treatment.
The “treated” form of WP-chitosan is prepared by… “dialyzing the chitosan against water and various salts and/or anionic solutions. In these embodiments, the treated chitosans have structural conformations that are identifiably and reproducibly altered from untreated chitosan”. WP-chitosan in “modified” state is proprietary treated chitosan that is altered through chemically attaching or associating functional groups to the treated chitosan molecule. A functional group is selected to produce a desired property, including the performance of a specific chemical coupling.
Elevated adhesive strength is a cardinal WP-chitosan quality. Comparative bond shear strengths (g-f/cm2) are revealing. WP-chitosan bond strengths exceed those of competitive technologies and untreated chitosan. In skin-to-skin matchups, WP-chitosan prevails with a measured sheer strength of 516 ± 258 g-f/cm2 vs. 385 ± 119 for the cyanoacrylate and 261 ± 51 for the fibrin adhesive.
The untreated chitosan bond registered a shear strength of 238 ± 92 compared to WP-chitosan’s 1164 ± 546 in cornea-to-cornea testing.
This durable bonding makes possible significantly extended retention of pharmaceutical, cosmeceutical, and other active agents on the skin.
WP-chitosan enables a delivery system of programmed retention and uniform release of pharmaceuticals, neutriceuticals, biocides, and other agents. The release can be timed or in response to a change of hydrolytic, photolytic, or enzymatic state. The bonding-to-release intervals can be scheduled for periods from a few minutes up to several days.
Proof of concept testing demonstrates that the system improves delivery and bioavailability of retained actives. In tests of opthalmalic drugs applied in the eye, the WP-chitosan retention and release system was more effective than the commercial formulations in terms of bioavailable quantities delivered, (i.e. more therapy, less medicine).
Evidence points to a safe and biocompatible WP-chitosan.
Taking into account untreated chitosan’s long history of internal and topical human use, this is expected.
Cell culture assays of rabbit endothelial tissue and in vivo evaluations (corneal pockets) revealed no significant issues of cell death, inflammation, or immune response.
In many cases, WP-chitosan can be used as a safe, strong substitute for commercial adhesives with toxicity issues that are currently used in personal care products.