Biomaterial Database

The "ultra-free" ultrafiltration technique compared with equilibrium dialysis for determination of unbound thiopental concentrations in serum. 1981

D Jung, and M Mayersohn, and D Perrier

We compare a new ultrafiltration technique, involving a unique Millipore membrane, with the classical method of equilibrium dialysis for determining the fraction of thiopental not bound to serum proteins. This fraction, as determined by equilibrium dialysis at 37 degrees C, ranged between 12 and 16% for total concentrations at 50 microgram/L to 10 mg/L of serum. In contrast, ultrafiltration at 37 degrees C yielded a 49% higher value for unbound thiopental: 26.3 (SD 2.6)%. Determined at room temperature (24 degrees C), there was no statistically significant difference for results by the two methods: 14.2 and 15.9%, respectively. The discrepancy between results at 37 degrees C may partly be explained by serum proteins penetrating the Ultra-Free filter. For the routine clinical measurement of unbound drug concentrations, the ultrafiltration membrane at room temperature appears to be sufficiently accurate and less time-consuming than equilibrium dialysis.

UI	MeSH Term	Description	Entries
D008851	Micropore Filters	A membrane or barrier with micrometer sized pores used for separation purification processes.	Millipore Filters,Filter, Micropore,Filter, Millipore,Filters, Micropore,Filters, Millipore,Micropore Filter,Millipore Filter
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D001774	Blood Chemical Analysis	An examination of chemicals in the blood.	Analysis, Blood Chemical,Chemical Analysis, Blood,Analyses, Blood Chemical,Blood Chemical Analyses,Chemical Analyses, Blood
D001798	Blood Proteins	Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.	Blood Protein,Plasma Protein,Plasma Proteins,Serum Protein,Serum Proteins,Protein, Blood,Protein, Plasma,Protein, Serum,Proteins, Blood,Proteins, Plasma,Proteins, Serum
D003956	Dialysis	A process of selective diffusion through a membrane. It is usually used to separate low-molecular-weight solutes which diffuse through the membrane from the colloidal and high-molecular-weight solutes which do not. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Dialyses
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013874	Thiopental	A barbiturate that is administered intravenously for the induction of general anesthesia or for the production of complete anesthesia of short duration.	Penthiobarbital,Thiomebumal,Thiopentobarbital,Bomathal,Nesdonal,Pentothal,Pentothal Sodico,Sodipental,Thionembutal,Thiopental Nycomed,Thiopental Sodium,Thiopentone,Tiobarbital Braun,Trapanal
D014462	Ultrafiltration	The separation of particles from a suspension by passage through a filter with very fine pores. In ultrafiltration the separation is accomplished by convective transport; in DIALYSIS separation relies instead upon differential diffusion. Ultrafiltration occurs naturally and is a laboratory procedure. Artificial ultrafiltration of the blood is referred to as HEMOFILTRATION or HEMODIAFILTRATION (if combined with HEMODIALYSIS).