Narrow poly- and mono-dispersed anoinic oligomers, and their uses, formulations and process

A process for the preparation of narrow polydispersed anionic oligomers, having a polydispersity ratio of 1.0 to 1.3, which are water-soluble oligomers comprising 3 to 50 recurring units coupled by carbonyl linking moieties, said oligomer having anionic groups and predominantly linear geometry such that regular spacing between anionic groups exists in an aqueous medium, and which are represented by any one of the following formulae:

• A) polyureas of the formula:
• ##STR31## wherein:
• R represents hydrogen, C.sub.1-20 alkyl, phenyl, or phenyl substituted with from 1 to 2 --SO.sub.3 R.sup.2 moieties and up to 3 substituents independently selected from chloro, bromo or C.sub.1-4 alkyl;
• R.sup.2 represents hydrogen or a pharmaceutically acceptable cation;
• m is 0 or 1, with the proviso that when m is 0, R is hydrogen;
• X represents:
• ##STR32## n is 3-50;
• and R.sup.3 represents --R or --X--NH.sub.2 where R and X are defined as before;
• B) polycarbonates of the formula:
• ##STR33## wherein:
• X and n are defined as in Formula I above;
• X.sup.1 represents HO--X--, wherein X is defined as in Formula I above, C.sub.1-20 alkyl, phenyl or phenyl substituted with from 1 to 2 --SO.sub.3 R.sup.2 moities and up to 3 substituents independently selected from chloro, bromo or C.sub.1-20 alkyl;
• and
• X.sup.2 represents hydrogen or --CO.sub.2 X.sup.1, wherein X.sup.1 is defined as above;
• C) polyesters of the formula:
• ##STR34## wherein:
• X and n are defined as in Formula 1 above;
• R.sup.4 represents --R.sup.2, as defined above in Formula 1, or --X.sup.1, as defined above in Formula II;
• R.sup.5 represents:
• ##STR35## wherein R.sup.4 is defined above as in Formula III above, or --R.sup.2 as defined in above Formula I;
• X.sup.3 represents:
• ##STR36## D) polyamides of the formula:
• ##STR37## wherein:
• X and n are defined as above in Formula I;
• X.sup.3 is defined as above in Formula III;
• R.sup.6 represents H.sub.2 N--X--NH--, R.sup.2 O--, RNH-- or R--C(O)--NH--X--NH--, where R, R.sup.2 and X are defined above as in Formula I;
• R.sup.7 represents hydrogen, ##STR38## wherein R and R.sup.2 are defined as above in Formula I, and X.sup.3 is defined above as in Formula III,
• which comprises the steps of:
• 1) restricting a crude polydispersed anionic oligomer mixture, having a polydispersity ratio>1.3, containing oligomers of one of Formulas I-IV to a narrow polydispersed anionic oligomer mixture, wherein the manner of restricting is chosen from a group consisting of gel filtration, membrane permeation and reverse phase chromatography;
• optionally followed by;
• 2) isolating a monodispersed anionic oligomer mixture;
• and
• 3) optionally converting the narrow polydispersed or monodispersed anionic oligomer mixtures from step 1) or 2) into a desired pharmaceutically-acceptable salt.