Search results for "Polymer ratio"
showing 3 items of 3 documents
SUPRAMOLECULAR ASSOCIATION OF RECOMBINANT HUMAN GROWTH HORMONE WITH HYDROPHOBIZED POLYHYDROXYETHYLASPARTAMIDES
2008
Abstract The protein delivery properties of polymer supramolecular assemblies were investigated by using recombinant human growth hormone (rh-GH) and two polyhydroxyethylaspartamide (PHEA) derivatives: (a) PHEA-C 16 obtained by PHEA random grafting with hexadecylalkylamine; (b) PHEA-PEG 5000 -C 16 obtained by PHEA random co-grafting with hexadecylalkylamine and 5 kDa poly(ethylene glycol). The two polymers possessed similar self-assembling properties: critical micelle concentration (CMC) and particle size. The protein loading (protein/polymer, w/w, %) was 12.1 ± 1.3% and 8.5 ± 0.4% with PHEA-C 16 and PHEA-PEG 5000 -C 16 , respectively. The rh-GH/polymer association constant calculated by Sc…
Preparation and Characterisation of Alendronate-Loaded Chitosan Microparticles Obtained Through the Spray Drying Technique
2009
Microparticles of chitosan (CHT) containing alendronate sodium (AL) were prepared in four drug:polymer ratios (1:1, 1:2, 1:4, 1:6) using the spray drying technique. The efficiency of the method was evaluated by determining production yield (about 70 %) and microencapsulation efficiency, which was almost 100 % in the case of all four of the formulations studied. Particles had a mean size of between 3.6 and 4.6 microm, and a near-spherical shape. The formulations with the highest content of AL (drug:polymer ratio 1:1 and 1:2) showed an asymmetrical distribution of particles, which were larger in size, and had a higher proportion of irregular particles than the other formulations. FT-IR analys…
Relative strength of H-bonding groups on biodegradable polymer-based blends in solution
2006
The intermolecular hydrogen bonding interactions between poly(3-hydroxybutyrate) and poly(styrene-co-vinyl phenol) copolymers with mutual solvent epichlorohydrin were thoroughly investigated by steady-state fluorescence and viscosity techniques. Fluorescence spectroscopy along with viscosity technique was used to asses the intermolecular hydrogen bonding between poly-(3-hydroxybutyrate) and its blends with five copolymer samples of styrene–vinyl phenol, containing different proportions of vinyl phenol but similar average molecular weight and polydispersity index. In the case of very low OH contents (2–4 mol %), as expected, both components of poly(3-hydroxybutyrate) and poly(styrene-co-4-vi…