Solubilization and Dissolution

Crison, G. L. Amidon. pH and surfactant-facilitated in vitro solubilization and dissolution of ketoprofen, a class II drug. Implications for waiver of bioavailability and bioequivalence studies (Unpublished). 

Sheng, J. J., N. A. Kasim, R. Chandrasekharan, and G. L. Amidon. 2006. Solubilization and dissolution of insoluble weak acid, ketoprofen Effects of pH combined with surfactSnt. J. Pharm. Sci. 29 306-314. 

Aromatic steroids are virtually insoluble in liquid ammonia and a cosolvent must be added to solubilize them or reduction will not occur. Ether, ethylene glycol dimethyl ether, dioxane and tetrahydrofuran have been used and, of these, tetrahydrofuran is the preferred solvent. Although dioxane is often a better solvent for steroids at room temperature, it freezes at 12° and its solvent effectiveness in ammonia is diminished. Tetrahydrofuran is infinitely miscible with liquid ammonia, but the addition of lithium to a 1 1 mixture causes the separation of two liquid phases, one blue and one colorless, together with the separation of a lithium-ammonia bronze phase. Thus tetrahydrofuran and lithium depress the solubilities of each other in ammonia. A tetrahydrofuran-ammonia mixture containing much over 50 % of tetrahydrofuran does not become blue when lithium is added. In general, a 1 1 ratio of ammonia to organic solvents represents a reasonable compromise between maximum solubility of steroid and dissolution of the metal with ionization. 

Roasted and ground coffee is packed into columns and percolated by the passage of hot water under pressure at about 340°F. The use of pressurized boiling water not only brings about the dissolution of the most readily water-soluble coffee extractables, it also causes the solubilization and possibly the hydrolysis of complex carbohydrates. Water-soluble compounds of a smaller molecular weight are produced. The extent of possible... 

A good deal of attention recently has been directed towards the use of derivatives of cyclodextrin for the solubilization and stabilization of pharmaceuticals [124 126]. One cautionary note—complexation may adversely affect the dissolution an/or permeability characteristics of the drug, thereby possibly decreasing drug bioavailability. 

P Singh, S Desai, D Flanagan, A Simonelli, W Higuchi. Mechanistic study of the influence of micelle solubilization and hydrodynamic factors on the dissolution rate of solid drugs. J Pharm Sci 57 959, 1968. 

Some of the better solvents for pure SWNTs are the amide-containing ones, like DMF or N-methylpyrrolidone, but they still do not permit full dissolution, just dispersion (Boul et al., 1999 Liu et al., 1999). The addition of surfactants to carbon nanotube suspensions can aid in their solubilization, and even permit their complete dispersion in aqueous solution. The hydro-phobic tails of surfactant molecules adsorb onto the surface of the carbon nanotube, while the hydrophilic parts permit interaction with the surrounding polar solvent medium. 

The complete disintegration and dissolution of the mineral material. This method frees the largely intact kerogen. Concentrated hydrofluoric acid is the most widely used reagent in this class (6,7) since it is still the only reagent that can effectively solubilize the silicate mineral (clay and quartz) that is resistant to most chemical treatments. 

It is generally believed that the mechanism of bioavailability enhancement by CD complexation is through solubility and dissolution rate improvement. However, it should be also noted that CDs might also alter the lipid barrier of the absorption site, which may contribute to the enhanced drug absorption. This effect of CDs on the lipid barrier can be attributed to CDs ability to form complexes with membrane components such as cholesterol, phospholipids, and proteins (Nakanishi et al., 1992). Jambhekar et al. (2004) compared the solubilizing effeqte D, HP-ft-CD, and H -CD on IM. 

The components and properties of aqueous Gl L uids to which a dosage form is exposed are important in determining the rate of dissolution and the level of solubilization, and therefore, the pattern... 

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