Macromolecular prodrugs. XIII. Hydrosoluble conjugates of 17β-estradiol and estradiol-17β-valerate with polyaspartamide polymer.
ACTA PHARMACEUTICA 2011;
61:465-72. [PMID:
22202205 DOI:
10.2478/v10007-011-0039-x]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Two hydrosoluble conjugates of 17β-estradiol (ED) and estradiol-17β-valerate (EV) with polyaspartamide polymer were prepared and characterized. ED and EV were first chemically modified and bound to poly[α,β-(N-2-hydroxyethyl-DL-aspartamide)]-poly[α,β-(N-2-aminoethyl-DL-aspartamide)] (PAHA), a hydrosoluble polyaspartamide-type copolymer bearing both hydroxyl and amino groups. ED was first converted to 17-hemisuccinate (EDS) and then bound to PAHA. In the resulting conjugate PAHA-EDS, the estradiol moiety was linked to the polymer through a 2-aminoethylhemisuccinamide spacer. On the other hand, EV was first converted to estradiol-17β-valerate-3-(benzotriazole-1-carboxylate), which readily reacted with amino groups in PAHA affording the polymer-drug conjugate PAHA-EV. In the prepared conjugate PAHA-EV, the estradiol moiety was covalently bound to the polyaspartamide backbone by carbamate linkage, through an ethylenediamine spacer. The polymer-drug conjugates were designed and prepared with the aim to increase water-solubility, bioavailability and to improve drug delivery of the lipophilic estrogen hormone.
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