Preparation and characterization of nanoparticles based on dextran–drug conjugates

Polymer-Drug Nanoconjugate – An Innovative Nanomedicine: Challenges and Recent Advancements in Rational Formulation Design for Effective Delivery of Poorly Soluble Drugs

“…Further examples of polymer-anticancer nanoconjugates with their particles size and drug-loading efficiency are presented in Table 1. In similar studies Hornig et al, 2009 reported drug loading efficiency of 37 to 71% for a chemically synthesized ibuprofen-dextran (dextran ester) conjugates (206). Also 30% loading efficiency of ibuprofen in polymer-coated SiO 2 particles (226); 10% ibuprofen loading in lipid nanoparticles e.g.…”

“…For example Hornig et al dispersed aqueous solution of ibuprofen-sodium salt or naproxen in DMSO under continuous stirring for 24 h followed by addition of appropriate quantities of dextran and N,Ncarbonyldiimidazole (CDI) with continuous stirring for 24 h at 80 o C to allow reaction between the drug and the polymer. The final product was isolated by precipitation in large volume of water and washed several times followed by vacuum drying (206). This is a simple process however complete removal of the residual amount of organic solvent cannot be assumed.…”

“…The nanosized drugs can also be covalently or non-covalently conjugated to the polymer backbone directly or via biodegradable spacers or linkers as discussed above. For example Hornig et al prepared dextran-drug conjugates by functionalizing water soluble biopolymer dextran with poorly water soluble drugs (ibuprofen and naproxen) through in situ activation of of the carboxylic acid group with N,N-carbonyldiimidazole (CDI) to produce hydrophobic derivative which self-assembled by nanoprecipitation into nanoparticles with 37 -71% drug loading efficiency (206). In this case the degree of substitution (DS) and the preparation technique dictate the particle size, particle size distribution, polydispersity index (PDI) and drug loading efficiency of the resulting nanoparticles.…”

“…For example PS and PSD of the nanoconjugates strongly depend on the solvent used, concentration of the polymer solution as well as the degree and characteristics of the substituents. Hornig et al have shown that nanoconjugates prepared by dialysis or dropping technique do not differ in their structure however PS tend to increase from 102 to 309 nm as degree of substitution increased from 0.5 to 2.08 while polydispersity index increased from 0.065 to 0.2333 suggesting remarkably reduced uniformity in PSD (206). They hypothesized that the hydrophobic ibuprofen molecules are located in interior of the nanoconjugate because it is well documented that dextran nanoparticles exhibit hydrophobic core.…”

Intranasal brain-targeted clonazepam polymeric micelles for immediate control of status epilepticus: in vitro optimization, ex vivo determination of cytotoxicity, in vivo biodistribution and pharmacodynamics studies

“…A higher electric charge on the surface of the nanoparticles will prevent aggregation because of the strong repellent forces among particles giving more stable dispersions (Honary & Zahir, 2013). Generally, ZP values above 20 mV indicate that nanosuspensions are well dispersed with considerable stability (Hornig et al, 2009). Results of ZP are compiled in Table 3, it ranged from À7.12 mV (PM2) to À28 mV (PM15) indicating that some formulae had better stability (higher than 20 mV) than others.…”