PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 15681089

Adjusting drug diffusivity using miscible polymer blends.

Su-Ping Lyu·Randall Sparer·Christopher Hobot·Kiem Dang
View original source ↗Export metadata ↓

Abstract

Tuning the release rates of drugs was accomplished with miscible polymer blends. Dexamethasone (DX) was formulated in a miscible polymer blend composed of two poly(ether urethane)s, one in which DX diffuses relatively quickly and the other in which DX diffuses relatively slowly. Matrices that provide drug diffusion coefficients from 7 x 10(-13) to 3 x 10(-19) cm2/s were obtained by adjusting the blend ratio. Tunable diffusion coefficients were also achieved with partially miscible blends, such as poly(vinyl acetate) (PVAC)/cellulose acetate butyrate (CAB). However, similar tunable diffusion was not observed with an immiscible polymer blend composed of poly(carbonate urethane) (PCU) and polysulfone (PSF).

Explore related subjects

DiffusionPharmaceutical PreparationsPolymersSolutionsJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Su-Ping Lyu, Randall Sparer, Christopher Hobot, Kiem Dang. 2005-02-16. Adjusting drug diffusivity using miscible polymer blends.. https://doi.org/10.1016/j.jconrel.2004.11.007

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Effect of surface treatment on diffusion and domain formation in supported lipid bilayers.

Supported lipid bilayers are widely used as model systems due to their robustness. Due to the solid support, the properties of supported lipid bilayers are different from those of freestanding bilayers. In this article, we examine whether different surface treatments affect the properties of supported lipid bilayers. It will be shown that depending on the treatment method, the diffusion of the lipids can be adjusted approximately threefold without altering the composition. Additionally, as the bilayer-support interaction decreases, it becomes easier to form coexisting liquid-ordered and liquid-disordered domains. The physical/chemical alterations that result from the different treatment methods will be discussed.

Diffusion↗
PubMed2007

An early example of evidence-based medicine: hypoxemia due to nitrous oxide.

Diffusion anoxia. By Bernard Raymond Fink. Anesthesiology 1955; 16:511-14. In 1955, Dr. Bernard Raymond Fink published his findings that described the mechanism by which hypoxemia occurred when nitrous oxide-oxygen anesthesia was discontinued and room air breathing commenced. Using an ear oximeter and brachial artery blood gases, he measured oxygen saturation in eight healthy patients who had received 75% nitrous oxide-25% oxygen for gynecologic surgery. He showed that oxygen saturation decreased from 5% to 10% and often reached a value below 90% when the patient began room air breathing after the nitrous oxide-oxygen was discontinued. The effect was seen over a 10-min period. He concluded that "anoxia arises because the outward diffusion of nitrous oxide lowers the alveolar partial pressure of oxygen." This phenomenon can become a causative factor of cardiac arrest in patients with impaired pulmonary or cardiac reserves.

Diffusion↗