Controlled Release of Model Drug from Biodegradable Segmented Polyurethane Ureas: Morphological and Structural Features

Abstract

Summary: Segmented polyurethane ureas (SPUUs), which are being used in implant devices, were evaluated as drug delivery matrices using theophylline as a model drug without much sacrificing the mechanical properties of films after drug doping. SPUUs were synthesized from aliphatic diisocyanate (lysine methyl ester diisocyante (LDI)), poly(caprolactone) diol with molecular weights 530, 1250 and 2000 and 1,4-butanediamine. Three series of segmented SPUUs were prepared with various soft segment lengths and were characterized by Fourier transform infrared spectroscopy, dynamic viscoelastic measurements and tensile testing. A single tand peak was observed in dynamic viscoelastic measurements, which revealed phase mixing of hard and soft segments. Low elongation at break was observed in case of PCL 2000 based SPUUs, may be due to partial cystallization of PCL segment. The degradation of SPUUs in alkaline solution and in vitro drug release of theophylline in pH 7.4 buffer were also investigated. The drug release behavior from these films were analyzed by the exponent relation M t /M 1 ¼ kt n , where k and n are constants and M t /M 1 is the fraction of drug released until time, t. The constant n was found to be close to 0.5 in all samples, which suggests the release of drug from these polymers can be explained by the Fickian diffusion model.

Thermosensitive Transparent Semi-Interpenetrating Polymer Networks for Wound Dressing and Cell Adhesion Control

“…The maximum in the loss modulus (E′′) at low frequencies is, however, very close to T g . From Figure 2, the temperature corresponding to E′′, very close to T g as obtained from DSC reported elsewhere, 18 was found to be ∼-19°C for the parent polymer. In the semi-IPN systems, the effect of PNiPAAm content on the PCL(530)(50)LDI-BDA network is observed as variation of T g compared to the parent system.…”

Polyurethane for biomedical applications: A review of recent developments

“…Reddy et al (2006) found that the release of drugs from those synthesized polyurethanes can be explained by the Fickian diffusion model.…”

Nanoengineered Drug Delivery Systems for Enhancing Antibiotic Therapy

“…They have a prolific effect on microbicidal and biofilm inhibition activity, biocompatibility, and drug targeting . Hyperbranched polyurethane (HBPU) is a well‐known wound healing material and potent drug carrier . Its application, along with Fe 3 O 4 –MWCNT NH to form Fe 3 O 4 –MWCNT NH/HBPU nanocomposites (NNCs), has been explored in the development of effective wound healing material.…”