Ampicillin-Ester Bonded Branched Polymers: Characterization, Cyto-, Genotoxicity and Controlled Drug-Release Behaviour

Abstract

Abstract:The development and characterization of novel macromolecular conjugates of ampicillin using branched biodegradable polymers has been described in this study. The conjugates have been prepared coupling the β-lactam antibiotic with branched polymer matrices based on the natural oligopeptide core. The cyto-and genotoxicity of the synthesized polymers were evaluated with a bacterial luminescence test, two protozoan assays and Salmonella typhimurium TA1535. The presence of a newly formed covalent bond between the drug and the polymer matrices was confirmed by 1 H-NMR and FTIR studies. A drug content (15.6 and 10.2 mole %) in the macromolecular conjugates has been determined. The obtained macromolecular products have been subjected to further in vitro release studies. The total percentage of ampicillin released after 21 days of incubation was nearly 60% and 14% and this resulted from the different physicochemical properties of the polymeric matrices. This is the first report on the application of branched biodegradable polymeric matrices for the covalent conjugation of ampicillin. The obtained results showed that the synthesized macromolecular drug-conjugates might slowly release the active drug molecule and improve the pharmacokinetics of ampicillin.

Electrospun fibers of poly(l‐lactic acid) containing lovastatin with potential applications in drug delivery

“…In order to investigate the drug release characteristics from ES fibers containing lovastatin, experiments were carried out using a 1.0% PBS solution as the release medium, at a controlled temperature of 37 °C. A magnetic stirrer rotating at 50 rpm was added to simulate human body conditions . The amount of drug released at various times was determined by UV absorbance at a wavelength of 248 nm, A 248 , with the aid of the following calibration curve of lovastatin determined in the same release medium: where C is the lovastatin concentration in μg mL −1 .…”

“…A magnetic stirrer rotating at 50 rpm was added to simulate human body conditions. 21 The amount of drug released at various times was determined by UV absorbance at a wavelength of 248 nm, A 248 , with the aid of the following calibration curve of lovastatin determined in the same release medium 20 :…”

“…where C is the lovastatin concentration in lg mL 21 . The cumulative percentage of drug released, RC, was calculated as a function of total embedded lovastatin, C total , using:…”

“…Nanotechnology provides a novel method for many biomedical applications especially for controlling drug delivery. Use of polymeric hosts for drug delivery allows improvements in therapeutic efficiency, with reduction of toxicity, and enhanced absorption rate. However, some issues still need to be overcome: drugs need to be spatially targeted and need to be released over a period of time.…”

“…However, some issues still need to be overcome: drugs need to be spatially targeted and need to be released over a period of time. Recent investigations have been focused both on preparing biocompatible polymer nanocomposites (nanoparticles in a polymer host) for controlled release applications, and on different methods for creating the delivery system. These include electrospinning (ES) of non‐woven membranes, microextrusion, blend or copolymer phase separation and self‐assembly, and incorporation into micelles …”