Absorbable suture anhydride

In the 1930 s, Carothers prepared a series of aliphatic poly(anhydride)s for potential use as fibers in the textile industry (1). However, the hydrolytic stability of these materials was very poor. By the mid-1950 s, Conix was able to synthesize aromatic poly(anhydride)s with improved film and fiber forming properties (2). Despite these properties, the polyanhydrides poor thermal and hydrolytic stability resulted in their limited use, and no conunercial applications were found. By the late 1960 s, however, hydrolytic instability became an important factor for polymers utilized in the manufacture of medical devices such as absorbable sutures and drug delivery systems. 

Polymers used in medicine fall into two main categories those that are sufficiently inert to fulfill a long-term structural function as biomaterials or membranes, and those that are sufficiently hydrolytically unstable to function as bioeradible materials, either in the form of sutures or as absorbable matrices for the controlled release of drugs. For the synthetic organic polymers widely used in biomedicine this often translates to a distinction between polymers that have a completely hydrocarbon backbone and those that have sites in the backbone that are hydrolytically sensitive. Ester, anhydride, amide, or urethane linkages in the backbone usually serve this function. 

Groftflns Interest in synthetic, absorbable copolymers and their use in the production of fibers, including sutures, and drug delivery systems has been addressed in the patent and technical literature over the past fifteen yearsHowever, most investigators have focused their attention on copolymers which are derived primarily from -hydroxy acids anhydrides ... 

Poly(glycolide), with the monomeric unit - CO—CH2—O, is available through polymerization of the cyclic dimer (glycolide) or the 0-carboxylic acid anhydride of the acid glycol. Surgical suturing thread can be made from this polymer, since it is absorbed by the body instead of being encapsulated and does not cause inflammation. 

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