High-performance liquid chromatographic determination of some of the hydrolytic decomposition products of poly(alpha-hydroxyacid)s.
An HPLC procedure is described for the separation and identification of some hydrosoluble by-products resulting from the hydrolytic degradation of poly(alpha-hydroxyacid)s having biomedical interest: poly(L-lactide), poly(DL-lactide), poly-(glycolide) and poly(lactide-co-glycolide). Peak identification was performed by comparing the respective retention times with those of pure standards. It was observed that optimum shape and separation of peaks are considerably affected by the composition of the mobile phase, consisting of acetonitrile (A) and a 0.006 M K2HPO4 buffer (B), and, in particular, its pH and A:B ratio, which had to be adjusted to around 5.8 and 75:25 (v/v), respectively. Under the investigated experimental conditions (aqueous suspension, 100 degrees C for 12 h under stirring), poly(L-lactide) is quite stable, poly(glycolide) degrades easily to glycolic acid, whereas poly(DL-lactide) and poly(DL-lactide-co-glycolide) exhibit intermediate behaviour. Upon hydrolytic decomposition, these poly(alpha-hydroxyacid)s yield not only the corresponding acids, but also their linear dimers and, possibly, trimers, tetramers and higher oligomers.
Marcato
B
B
Montell Polyolefins, Centro Ricerche G. Natta, Ferrara, Italy.
Paganetto
G
G
Ferrara
G
G
Cecchin
G
G
D002851:Chromatography, High Pressure Liquid; D019281:Dimerization; D006016:Glycolates / Q000737:chemistry; D006358:Hot Temperature; D006868:Hydrolysis; D006880:Hydroxy Acids / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D011091:Polyesters / Q000032:analysis* / Q000737:chemistry*; D011098:Polyglactin 910 / Q000032:analysis / Q000737:chemistry; D011100:Polyglycolic Acid / Q000032:analysis / Q000737:chemistry; D011108:Polymers / Q000032:analysis* / Q000737:chemistry*; D013237:Stereoisomerism; D013997:Time Factors
D006016:Glycolates; D006880:Hydroxy Acids; D011091:Polyesters; D011108:Polymers; C031149:glycolic acid; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011098:Polyglactin 910; C033616:poly(lactide)