Salt form wettability

Because a balance between different salt properties needs to be taken into consideration in assessing the correct salt form to progress into drug development, some decision-making models have been developed to aid in the selection of an appropriate salt form. Gould described a salt selection process based on melting point, solubility, stability, wettability, etc. of various salt forms. However, in the absence of clear go/no go decisions at any particular stage of the salt selection process, this approach would lead to the... 

The factors described earlier that affect the solubility of a lead compound when choosing a particular salt form—a polymorphic form—a specific crystalline form directly affects the most critical parameter that determines the drug activity, which is the dissolution rate in the biological milieu. The first step in the commencement of dissolution is the wettability of solid particles—there is a direct correlation between wettability and bioavailability. As the milieu of drug administration sites is mostly aqueous in nature, low wettability makes the particles less hygroscopic. 

Dithane [Rohm Haas], TM for agricultural fungicides based on salts of ethylene bisdithio-carbamate. Supplied in zinc, manganese, and sodium forms as wettable powder or liquid concentration. 

Mancozeb is a polymeric mixture of a zinc salt and maneb containing 20% of manganese and 2.55% of zinc (HSDB 1999). Its chemical name is manganese ethylenebis(dithiocarbamate) (polymeric) complex with zinc salt. It may be in the form of a wettable or dustable powder, a suspension concentrate, or dry seed treatment. 

The solubility of a compound is a barrier that limits its concentration in a solution and therefore the amovmt of material available for absorption. A compovmd s crystal type (polymorph), its particle size, wettability, and the use of solubilizing agents in formulations can all influence solubility. Also, the formation of salts, esters, and complexes with a compovmd can improve its solubility. Solubility is a key parameter for determining the dissolution rate of compovmds, a more informative measure that takes into accovmt the form and particle size distribution in a particular medium. 

The first study of PTh and PPy wettability was reported in 1984 [27]. Derivatives of thiophene and pyrrole were polymerized in a classical electrolytic medium, i.e. acetonitrile and tetrabutylammonium tetrafluoroborate as the electrolytic salt. The thickness of the film was approximatively 0.5 pm and the water contact angles reported (86° for PTh and 62° for PPy) indicate their hydrophilicity. These electropolymerized films have the advantage to show exceptional stability for several months. In the oxidized form, the films are ionic composites. Electrochemically... 

The recovery of naturally acidic oils by alkaline flooding fits into the phase alteration category. The recovery mechanisms of these floods are varied since the surface active salts, which are formed by the in situ acid-base reaction, can adsorb onto the oil-water interface to promote emulsification or can absorb onto the rock surface to alter wettability. The exact recovery mechanism, recently reviewed by Johnson (3) depends on the pH and salinity of the aqueous phase, acidity of the organic phase and wettability of the rock surface (4,5). In this study an additional alkaline recovery mechanism is explored. This mechanism. Emulsification and Coalescence, depends on the valency of the electrolyte as well as the pH and salinity of the aqueous phase. The Emulsification and Coalescence mechanism for the recovery of acidic oils is similar to the Spontaneous Emulsification mechanism suggested by Schechter et al. (6) for the recovery of nonacidic oils with petroleum sulfonate solutions. 

Blending of fibers based on i-PP, a polar group material (e.g. ethylene eopolymer, aerylie aeid or maleic anhydride), a hydrophilie modifier (0.1 2% monoglyceride), and a salt of a linear alkyl phosphate, either in the form of nonionie, anionie or eationic, highly wettable, spinnable fibers are provided. 

Sizes are additives that decrease the wettability of the paper for certain applications (printing with aqueous inks, manufacturing of milk cartons and paper cups). - Rosin (gum rosin, wood rosin or tall oil rosin) in the form of its sodium or potassium salt or as free acid are used as powder, solution or dispersion. They are excellent sizes, which are used together with alum to develop lull sizing power. Reaction products of rosin with maleic anhydride or fu-maric acid (fortified sizes) are more effective. They are saponified and used as pastes or dispersions. Free rosin emulsions are the newest and most effective sizes. For ordinary rosin 15-20 kg are necessary per mt of paper, fortified rosin requires 5-8 kg/mt and free rosin emulsion only 2-4 kg/mt to get the same effect. 

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