Abstract: Among other aspects, provided herein is a mixed-acid salt of a water-soluble polymer-drug conjugate, along with related methods of making and using the same. The mixed-salt acid salt is stably formed, and appears to be more resistant to hydrolytic degradation than the corresponding predominantly pure acid salt or free base forms of the polymer-drug conjugate. The mixed acid salt is reproducibly prepared and recovered, and provides surprising advantages over non-mixed acid salt forms of the water-soluble polymer drug conjugate.

Abstract: Among other aspects, provided herein is a mixed-acid salt of a water-soluble polymer-drug conjugate, along with related methods of making and using the same. The mixed-salt acid salt is stably formed, and appears to be more resistant to hydrolytic degradation than the corresponding predominantly pure acid salt or free base forms of the polymer-drug conjugate. The mixed acid salt is reproducibly prepared and recovered, and provides surprising advantages over non-mixed acid salt forms of the water-soluble polymer drug conjugate.

Abstract: Among other aspects, provided herein is a mixed-acid salt of a water-soluble polymer-drug conjugate, along with related methods of making and using the same. The mixed-salt acid salt is stably formed, and appears to be more resistant to hydrolytic degradation than the corresponding predominantly pure acid salt or free base forms of the polymer-drug conjugate. The mixed acid salt is reproducibly prepared and recovered, and provides surprising advantages over non-mixed acid salt forms of the water-soluble polymer drug conjugate.

Abstract: Among other aspects, provided herein is a hydrohalide salt of a multi-arm water-soluble polyethylene glycol-drug conjugate, along with related methods of making and using the same. The hydrohalide salt is stably formed, and appears to be more resistant to hydrolytic degradation than the corresponding free base form of the conjugate.

Abstract: Among other aspects, provided herein is a mixed-acid salt of a water-soluble polymer-drug conjugate, along with related methods of making and using the same. The mixed-salt acid salt is stably formed, and appears to be more resistant to hydrolytic degradation than the corresponding predominantly pure acid salt or free base forms of the polymer-drug conjugate. The mixed acid salt is reproducibly prepared and recovered, and provides surprising advantages over non-mixed acid salt forms of the water-soluble polymer drug conjugate.

Abstract: Among other aspects, provided herein is a hydrohalide salt of a multi-arm water-soluble polyethylene glycol-drug conjugate, along with related methods of making and using the same. The hydrohalide salt is stably formed, and appears to be more resistant to hydrolytic degradation than the corresponding free base form of the conjugate.

Abstract: Among other aspects, provided herein is a mixed-acid salt of a water-soluble polymer-drug conjugate, along with related methods of making and using the same. The mixed-salt acid salt is stably formed, and appears to be more resistant to hydrolytic degradation than the corresponding predominantly pure acid salt or free base forms of the polymer-drug conjugate. The mixed acid salt is reproducibly prepared and recovered, and provides surprising advantages over non-mixed acid salt forms of the water-soluble polymer drug conjugate.

Abstract: The present invention relates generally to methods for preparing polyethylene glycol maleimide (“PEG-Mal”). More specifically, the present invention relates to methods for synthesizing desired molecular weight PEG-Mal by direct ethoxylation of N-(2-hydroxyethyl)maleimide under specific reaction conditions.

Abstract: Methods for preparing polymeric reagents bearing a maleimide are provided. Also provided are related compositions.

Abstract: Improvements are shown in the successive preparations of N,N-bis(2-hydroxyethyl)benzylamine starting with benzyl chloride, its conversion to the corresponding N,N-bis(2-chloroethyl)benzylamine in substantially quantitative yield in toluene solution and using the latter by reaction with phenylacetonitrile in the presence of aqueous sodium hydroxide solution and a tetra-n-butylammonium salt, preferably the hydrogen sulfate, to produce improved over-all yields of up to over 75% (based on benzyl chloride) of 1-benzyl-4-cyano-4-phenylpiperidine hydrochloride, an intermediate for preparing meperidine.