Liquid disintegration

There may be many other types of periodical vibrations for liquid disintegration or dispersion in various applications. The features, operation parameters, performance and applications of various experimental and commercially available ultrasonic and acoustic atomizers have been described and compared by Topp and EisenklamJ129 ... 

Fig. 1 illustrates the two mechanisms proposed for the processes of liquid disintegration and aerosol generation within ultrasonic nebulizers. The capillary-wave theory relates to the production of capillary waves in the bulk liquid. These waves constructively interfere to form peaks and a central geyser. When the amplitude of the applied energy is sufficiently high, the crests of the capillary waves break off, and droplets are formed. The rate of generation of capillary waves is dependent on both the physicochemical properties of the nebulized fluid and the intensity of the ultrasonic vibration. Mercer used Eq. (1) to calculate the threshold amplitude for the generation of capillary waves ... 

The fundamental principle of liquid disintegration lies in the balance between disruptive and cohesive forces. The common disruptive forces in atomizer systems include kinetic energy, turbulent fluctuation, pressure fluctuation, interface shearing, friction, and gravity. The cohesive forces within the liquid are molecular bonding, viscosity, and surface tension. 

Gunther, A., Lampa, A., Fritsching, U., Schroder, J., Kleinhans, A., Gaukel, V., et al. (2015). Benchmarking of gas-assisted atomization systems for liquid disintegration. Chemical Engineering Science, 39(4), 699-707. 

Bubbles in a liquid originate from one of three general sources (1) They may be formed by desupersaturation of a solution of the gas or by the decomposition of a component in the liqiiid (2) They may be introduced directly into the liquid by a bubbler or sparger or by mechanical entrainment and (3) They may result from the disintegration of larger bubbles already in the liquid. 

Methods of Gas Dispersion The problem of dispersing a gas in a liqmd may be attacked in several ways (1) The gas nubbles of the desired size or which grow to the desired size may be introduced directly into the liqmd (2) a volatile hquid may be vaporized by either decreasing the system pressure or increasing its temperature (3) a chemical reaction may produce a gas or (4) a massive bubble or stream of gas is disintegrated by fluid shear and/or turbulence in the liquid. 

The filter aid should be chemically inert to the liquid phase of the suspension and not decompose or disintegrate in it. 

A liquid scintillation counter. This instrument is used to detect radiation and measure disintegrations per minute quickly and accurately. 

Note that olanzapine is available as a tablet to swallow or as an orally disintegrating tablet. When using the orally disintegrating tablet, peel back the foil on the blister. Using dry hands, remove the tablet and place the entire tablet in the mouth. The tablet will disintegrate with or without liquid. 

Sodium alcohol sulfates are also used in the formulation of synthetic soaps and paste hand cleaners, commonly together with other surfactants and as tablet disintegrators in the case of sodium dodecyl sulfate. Sodium, but preferably ammonium and alkanolamine salts, is also used in liquid soaps. 

The stress acting on particles is of high importance for many technical processes. As well as dispersion processes in two-phase systems (liquid/liquid or gas/Hquid), where the disintegration of particles is desirable, there are also a number of processes that may be adversely affected by particle disintegration. These include precipitation, agglomeration, crystalHsation processes, and also bio conversion with immobilised enzymes and the fermentation of sensitive microorganisms and animal and plant cells. 

Savignac, J. R., Fairhurst, C. W. Ryge, G. (1965). Strength, solubility and disintegration of zinc phosphate cement with clinically determined powder/liquid ratio. Angle Orthodontics, 35, 126-30. 

Gas or air may be dispersed into a liquid by mechanical means (beaters) or by introducing bubbles of desired size directly by disintegrating massive streams or bubbles of gas. Bubbles are introduced either by sprayers (simple bubbling) or by porous dispensers (diffusers). 

Difficulty swallowing tablets/capsules Risperidone or aripiprazole liquid, orally-disintegrating tablets (risperidone, olanzapine, clozapine) Long-acting risperidone... 

For most tablets, it is necessary to overcome the cohesive strength introduced into the mass by compression. It is therefore common practice to incorporate an excipient, called a disintegrant, which induces this process. Several types, acting by different mechanisms, may be distinguished (a) those that enhance the action of capillary forces in producing a rapid uptake of aqueous liquids, (b) those that swell on contact with water, (c) those that release gases to disrupt the tablet... 

The rate at which selected liquids penetrate into tablets can be used to study their pore structure. A knowledge of the rate of liquid penetration should also provide information on the disintegration/dissolution behavior of a tablet on administration. Such investigations are capable of forming a valuable link between physico-mechanical characteristics and in vivo performance. 

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