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Drug Delivery Vehicles (drug + delivery_vehicle)

Distribution by Scientific Domains

Polymers and Materials Science	50%
Chemistry	50%

Selected Abstracts

Photopolymerizable Hydrogels Made from Polymer-Conjugated Albumin for Affinity-Based Drug Delivery,

ADVANCED ENGINEERING MATERIALS, Issue 1-2 2010
Liat Oss-Ronen
As a drug delivery vehicle, biodegradable albumin hydrogels can combine the high binding capacity of albumin with the structural stability of a polymeric hydrogel network to enable controlled release of small molecules based on both binding affinity and physical interactions. In the present study, we report on the development of a hybrid hydrogel composed of albumin conjugated to poly(ethylene glycol) (PEG) for drug delivery applications where controlled release is accomplished using the natural affinity of the drugs to the serum albumin. Bovine serum albumin was conjugated to PEG-diacrylate having a molecular weight of 1.5, 4, or 10,kDa to form a PEGylated albumin macromolecule (mono-PEGylated or multi-PEGylated). Biodegradable hydrogels were formed from the PEGylated albumin using photopolymerization. Two model drugs, Warfarin and Naproxen, were used for equilibrium dialysis and release experiments from the hydrogels, both having relatively low molecular weights and a known high affinity for albumin. Equilibrium dialysis experiments showed that multi-PEGylation of albumin significantly decreased the drug affinity to the protein compared to non-PEGylated controls, irrespective of the PEG molecular weight. However, the results from drug release experiments showed that mono-PEGylation of albumin did not change its natural affinity to the drug. Comparing the release profiles with a Fickian diffusion model provided strong evidence that hydrogels containing mono-PEGylated albumin exhibited sub-diffusive drug release properties based on the affinity of the drug to the tethered protein. [source]

Self-emulsifying O/W formulations of paclitaxel prepared from mixed nonionic surfactants

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 5 2010
Jen-Ting Lo
Abstract Nonionic self-emulsifying oil-in-water (O/W) formulations free of Cremophore® were developed as drug delivery vehicles for paclitaxel. The surfactants used included phosphatidylcholine purified from egg yolk (EPC), Tween, and Span. Oils phases were either pure components or blends from benzyl alcohol, 2-phenylethanol benzyl benzoate, and tributyrin. Among these surfactants, mixtures of EPC and Tween-80 gave really stable emulsions in proper sizes ranging from 70 to 200,nm, mainly depends on the ratio of EPC to Tween-80 and amount of oils. Paclitaxel could be well preserved without any loss in oily stocks, namely mixtures of oils and paclitaxel as well as surfactants, stored at 4°C for more than 8 months. Only gentle mixing on oily stocks with aqueous diluents is enough to make paclitaxel-contained emulsions. The optimum formulation contains oils from 1 to 3 wt%, Tween-80 and EPC from 0.4 to 1.2 wt%, respectively. Consequently, near 500,ppm of paclitaxel can be contained in emulsions. Moreover, these paclitaxel-containing emulsions are compatible with commonly used injection fluids. No precipitation is observed upon preparation of emulsion from dilution of oily stocks. Negligible cytotoxicity on these emulsions assessed with NIH/3T3 cells implied their good biocompatibility and promising applications as drug delivery carriers. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99: 2320,2332, 2010 [source]

Interpenetrating polymeric network hydrogels for potential gastrointestinal drug release

POLYMER INTERNATIONAL, Issue 11 2007
Sema Ekici
Abstract New interpenetrating polymeric network (IPN) hydrogels based on chitosan (C), poly(N -vinyl pyrrolidone) (PVP) and poly(acrylic acid) (PAAc), crosslinked with glutaraldehyde (G) and N,N,-methylenebisacrylamide (MBA), were prepared and investigated for potential gastrointestinal drug delivery vehicles utilizing a model drug, amoxicillin. IPN hydrogels were synthesized by simultaneous polymerization/crosslinking of acrylic acid monomer in the presence of another polymer (C) and crosslinker (G, MBA). Three different concentrations of glutaraldehyde were used (0.5, 1.0 and 2.0 w/w) to control the overall porosity of the hydrogels, named C-P-AAc/0.5, C-P-AAc/1.0 and C-P-AAc/2.0, respectively. Spectroscopic and thermal analyses such as Fourier transform infrared spectroscopy, thermogravimetric analysis and thermomechanical analysis were performed for IPN characterization. Equilibrium swelling studies were conducted for pH and temperature response behavior. Swelling studies were also carried out in simulated gastric fluid of pH = 1.1 and simulated intestinal fluid of pH = 7.4 to investigate possible site-specific drug delivery. It was found that the release behavior of the drug from these IPN hydrogels was dependent on the pH of the medium and the proportion of crosslinker in the IPN. It was observed that amoxicillin release at pH = 7.4 was higher than at pH = 1.1. The analysis of the drug release showed that amoxicillin was released from these hydrogels through a non-Fickian diffusion mechanism. Copyright © 2007 Society of Chemical Industry [source]

HER-2-Targeted Nanoparticle,Affibody Bioconjugates for Cancer Therapy

CHEMMEDCHEM, Issue 12 2008
Frank Alexis Dr.
Affibodies are a class of polypeptide ligand that are potential candidates for tissue-specific targeting of drug-encapsulated controlled release polymeric nanoparticles (NPs). We developed drug delivery vehicles composed of polymeric NPs surface modified with affibody ligands that bind the extracellular domain of the human epidermal growth factor receptor,2 (HER-2) for targeted delivery to cells that overexpress the HER-2 antigen. [source]