Biomaterial Database

Some relations between dissolution rates and physical parameters of a drug in aqueous micellar solutions of a non-ionic surfactant. 1975

J H Collett, and J A Rees

Dissolution rates of salicylic acid from a constant surface area into a series of aqueous micellar polysorbate 20 solutions at pH 1-0 to 4-0 have been measured using two different methods; a stirred beaker and a rotating disc technique. The micellar molecular weight of polysorbate 20 has been obtained from light scattering and differential refractometry data and used with other independently determined physical data to calculate diffusion coefficients of the diffusing species. Linear multiple regression analysis was used to assess the dependence of drug dissolution rate on the diffusion coefficient and the viscosity of the dissolution medium.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008823	Micelles	Particles consisting of aggregates of molecules held loosely together by secondary bonds. The surface of micelles are usually comprised of amphiphatic compounds that are oriented in a way that minimizes the energy of interaction between the micelle and its environment. Liquids that contain large numbers of suspended micelles are referred to as EMULSIONS.	Micelle
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D011136	Polysorbates	Sorbitan mono-9-octadecanoate poly(oxy-1,2-ethanediyl) derivatives; complex mixtures of polyoxyethylene ethers used as emulsifiers or dispersing agents in pharmaceuticals.	Polysorbate,Polysorbate 20,Polysorbate 80,Sorbitan Derivatives,Tween,Tweens,PSML,Polyoxyethylene Sorbitan Monolaurate,Tween 20,Tween 60,Tween 80,Tween 81,Tween 85,20s, Polysorbate,20s, Tween,60s, Tween,80s, Polysorbate,80s, Tween,81s, Tween,85s, Tween,Derivative, Sorbitan,Derivatives, Sorbitan,Monolaurate, Polyoxyethylene Sorbitan,Monolaurates, Polyoxyethylene Sorbitan,PSMLs,Polyoxyethylene Sorbitan Monolaurates,Polysorbate 20s,Polysorbate 80s,Sorbitan Derivative,Sorbitan Monolaurate, Polyoxyethylene,Sorbitan Monolaurates, Polyoxyethylene,Tween 20s,Tween 60s,Tween 80s,Tween 81s,Tween 85s
D012044	Regression Analysis	Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.	Regression Diagnostics,Statistical Regression,Analysis, Regression,Analyses, Regression,Diagnostics, Regression,Regression Analyses,Regression, Statistical,Regressions, Statistical,Statistical Regressions
D003102	Colloids	Two-phase systems in which one is uniformly dispersed in another as particles small enough so they cannot be filtered or will not settle out. The dispersing or continuous phase or medium envelops the particles of the discontinuous phase. All three states of matter can form colloids among each other.	Hydrocolloids,Colloid,Hydrocolloid
D004058	Diffusion	The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.	Diffusions
D004364	Pharmaceutical Preparations	Drugs intended for human or veterinary use, presented in their finished dosage form. Included here are materials used in the preparation and/or formulation of the finished dosage form.	Drug,Drugs,Pharmaceutical,Pharmaceutical Preparation,Pharmaceutical Product,Pharmaceutic Preparations,Pharmaceutical Products,Pharmaceuticals,Preparations, Pharmaceutical,Preparation, Pharmaceutical,Preparations, Pharmaceutic,Product, Pharmaceutical,Products, Pharmaceutical
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D012459	Salicylates	The salts or esters of salicylic acids, or salicylate esters of an organic acid. Some of these have analgesic, antipyretic, and anti-inflammatory activities by inhibiting prostaglandin synthesis.	Salicylate,Salicylic Acids,Acids, Salicylic