Synthesis and characterization of polymeric matrices based on 2-hydroxyalkyl acrylate and itaconic acid for controlled release of oxaprozin

Abstract

In order to improve the efficiency of pharmacotherapy by development of the sophisticated drug delivery systems, two series of hydrogels were synthesized in this study. Hydrogels were synthesized by the free-radical crosslinking polymerization at 50 °C for 24 h. In the first series the polymeric hydrogels are based on 2-hydroxyethyl acrylate and itaconic acid, whereas in the second series the samples are based on 2-hydroxypropyl acrylate and itaconic acid. In order to investigate the influence of the hydrogel composition on its properties in both series of the hydrogels amount of the itaconic acid was varied (0.0; 2.0; 3.5; 5.0 and 7.0 mol %). The started monomers were selected as structural analogs of 2-hydroxyethyl methacrylate which is thoroughly investigated and widely used monomer especially in biomedical and pharmaceutical applications. In order to improve the hydrophilicity and pH-sensitivity of the synthesized copolymers itaconic acid was used. The hydrophobic drug - oxaprozin was successfully synthesized and incorporated into the hydrogels by diffusion method. For evaluation of synthesized hydrogels as polymeric matrices for drug delivery complexes of oxaprozin with transition metal (Ni(II) and Zn(II)) as potential antiproliferative agents were used also. In order to investigate the influence of the chemical composition and of the presence of drug on the properties of synthesized hydrogels, chemical structure, morphology, thermal properties, swelling and „intelligent’’ behavior of synthesized hydrogels were examined. The entrapment efficiency of drug into synthesized hydrogels and their application in controlled drug delivery systems were investigated. The therapeutic benefits of the oxaprozin are accompanied with several serious side effects in upper gastrointestinal tract. The goal of this study was to design the polymeric matrices which can prevent the release of oxaprozin in the acidic environment of the stomach and reduce its side effects in upper part of the gastrointestinal tract. Therefore, the study of drug release from investigated hydrogels...

U cilju unapređenja efikasnosti farmakoterapije razvojem sofisticiranih sistema za kontrolisano otpuštanje aktivnih supstanci u ovom radu su sintetisane dve serije hidrogelova reakcijom polimerizacije preko slobodnih radikala, na 50 °C u toku 24 h. Prvu seriju hidrogelova čine hidrogelovi na bazi 2-hidroksietil akrilata i itakonske kiseline (P(HEA/IK)), dok drugu seriju čine hidrogelovi na bazi 2-hidroksipropil akrilata i itakonske kiseline (P(HPA/IK)). U obe serije hidrogelova variran je molski udeo itakonske kiseline (0,0; 2,0; 3,5; 5,0 i 7,0 mol % IK) kako bi se ispitao uticaj sastava hidrogela na njegova svojstva kao matrice za kontrolisano otpuštanje aktivnih supstanci. Polazni monomeri, 2-hidroksietil akrilat i 2-hidroksipropil akrilat, su odabrani kao strukturni analozi temeljno ispitanog i opsežno primenjivanog (naročito u biomedicini i farmaciji) monomer - 2-hidroksietil metakrilat-a. U reakcijama kopolimerizacije je korišćena itakonska kiselina zbog njenog značajnog doprinosa hidrofilnosti i pH-osetljivosti sintetisanih kopolimera. Hidrofobna aktivna supstanca - oksaprozin je uspešno sintetisana i ugrađena u ispitivane hidrogelove metodom difuzije. Pored aktivne supstance oksaprozin, u cilju određivanja podobnosti sintetisanih hidrogelova kao polimernih matrica za kontrolisano otpuštanje aktivnih supstanci, korišćeni su i derivati oksaprozina (Ni(II) i Zn(II) kompleks sa oksaprozinom), kao potencijalno biološki aktivne supstance sa antiproliferativnim efektom. U cilju ispitivanja uticaja hemijskog sastava kao i prisustva aktivne supstance na svojstva sintetisanih hidrogelova, izvršena je analiza hemijske strukture, morfologije, termičkih svojstava, bubrenja i „inteligentnog“ ponašanja sintetisanih hidrogelova, pre i nakon ugradnje aktivne supstance. Pored toga, ispitana je efikasnost ugradnje aktivne supstance u sintetisane hidrogelove, kao i mogućnost njihove primene u vidu polimernih matrica za kontrolisano otpuštanje aktivnih supstanci. S obzirom da terapija oksaprozinom podrazumeva uglavnom njegovu dugoročnu oralnu upotrebu i neretko je praćena ozbiljnim neželjenim efektima posebno izraženim...