Poly Orthoesters POEs

In the early 1970s, the ALZA Corporation began its search for polymers suitable for erodible drug delivery systems. The ideal polymer was identified as one undergoing surface erosion in vivo and degrading to non-toxic, low molecular weight products at a rate that could be manipulated over a broad time span. To meet these criteria, a novel family of hydrolyzable polymers was developed, the poly(orthoesters), POEs [285]. The general structure is schematically shown in... 

Poly(orthoesters) (POEs) constitute a class of amorphous, hydrophobic, biodegradable polymers. Different families of POEs have been reported (Figure 2.52). In addition to their surface wearing down mechanism, the rate of degradation of POEs is pH sensitive. They can be easily dissolved in organic solvents together with chloroform, methylene chloride, and dioxane owing to their hydrophobic nature [375]. 

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