Friday, March 11, 2016

PolyVivo AK109: Thermogelling PLCL-PEG-PLCL for long-term delivery

PolySciTech division of Akina, Inc. (www.polyscitech.com) provides a wide array of biodegradable block copolymers including thermogelling PLCL-PEG-PLCL AK109. This polymer has a similar LCST property to its PLGA based counter-parts but, unlike PLGA, a much slower degradation time due to slow-degrading PLCL blocks.  Since a 20% w/v aqueous solution of this polymer is liquid it can easily be combined with microparticles or API directly. Then the solution can be injected where body heat solidifies the gel trapping the pharmaceutical so that it elutes out slowly for long term controlled release. You can learn more about in-situ thermogels and their usage in drug delivery in a well-written review article here: He, Chaoliang, Sung Wan Kim, and Doo Sung Lee. "In situ gelling stimuli-sensitive block copolymer hydrogels for drug delivery." Journal of controlled release 127, no. 3 (2008): 189-207. http://www.sciencedirect.com/science/article/pii/S0168365908000436

“Abstract: Stimuli-sensitive block copolymer hydrogels, which are reversible polymer networks formed by physical interactions and exhibit a sol–gel phase-transition in response to external stimuli, have great potential in biomedical and pharmaceutical applications, especially in site-specific controlled drug-delivery systems. The drug may be mixed with a polymer solution in vitro and the drug-loaded hydrogel can form in situ after the in vivo administration, such as injection; therefore, stimuli-sensitive block copolymer hydrogels have many advantages, such as simple drug formulation and administration procedures, no organic solvent, site-specificity, a sustained drug release behavior, less systemic toxicity and ability to deliver both hydrophilic and hydrophobic drugs. Among the stimuli in the biomedical applications, temperature and pH are the most popular physical and chemical stimuli, respectively. The temperature- and/or pH-sensitive block copolymer hydrogels for biomedical applications have been extensively developed in the past decade. This review focuses on recent development of the preparation and application for drug delivery of the block copolymer hydrogels that respond to temperature, pH or both stimuli, including poly(N-substituted acrylamide)-based block copolymers, poloxamers and their derivatives, poly(ethylene glycol)-polyester block copolymers, polyelectrolyte-based block copolymers and the polyelectrolyte-modified thermo-sensitive block copolymers. In addition, the hydrogels based on other stimuli-sensitive block copolymers are discussed. Keywords: Stimuli sensitive; Hydrogel; Block copolymer; Drug delivery; Response”


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