Partially esterified or amidated lactic or glycolic acid oligomers

摘要

The oligomers have a mol. wt. of 500-10,000. The free carboxy gp. of the oligomer is at least partially in the form of an amide gp. with an aminoacid or in the form of an ester gp. with a sterol. The prods. pref. have an acid index of 1.5 or less. Used for prepn. of delayed release forms of pharmacologically active cpds. The olifomers allow a sufficiently long release time for the active cpds. e.g. several weeks, and are appropriate for use with a wide variety of active cpds., such as those soluble in water. The oligomers are easy to manipulate, are less adhesive than polymers having free acid gps. and may be administered in the form of microcapsules (e.g. 10-60 microns) by a syringe, e.g. intramuscularly or sub-cutaneously.