Disintegrants classification

It is classification by contacting method that provides the two principal categories into which leaching equipment is divided (I) that in which the leaching is accomphshed oy percolation and (2) that in which particulate solids are dispersed into a hquid and subsequently separated from it. Each includes batch and continuous units. Materials which disintegrate during leaching are treated in equipment of the second class. 

The method used for grinding pressed cakes depends upon the nature of the cake, its purity, residual oil, and moisture content. If the whole cake is to be pulverized without removal of fibrous particles, it may be ground in a hammer mill with or without air classification. A 15-kW (20-hp) hammer mill with an air classifier, grinding pressed cake, had a capacity of 136 kg/h (300 Ib/h), 90 percent through No. 200 sieve a 15-kW (20-lm) screen-hammer mill grinding to 0.16-cm (Vi6-in) screen producea 453 kg/h (1000 Ib/h). In many cases the hammer mill is used merely as a preliminaiy disintegrator, followed by an attrition mill. Typical performance of the attrition mill is given in Table 20-25. A finer product may be obtained in a hammer mill in closed circuit with an external screen or classifier. 

The pore structure of a solid can contribute to the disintegration, dissolution, adsorption, and diffusion of a drug material [26,27]. Because of this, porosity and pore size distribution measurements have been used extensively to study tablets [28-30], granules [31,32], and excipients [33]. The following classification system of pore sizes has been developed based on the average pore radii [6] ... 

Protein content of field peas is negatively correlated with lipid, cell wall material (CWM), sugar, and ash content and positively correlated with starch separation efficiency and protein separation efficiency in air classification of pea flour. The lower separation efficiency of low protein peas may be due to their high lipid and CWM content which makes disintegration of seeds and separation into protein and starch particles by pin milling difficult. It is suggested that peas with a specific protein content should be used in order to control the protein and starch fraction contents (18). 

TABLE 1 Classification of Super Disintegrants (Partial Listing)... 

Excipients are sub-divided into various functional classifications, depending on the role that they are intended to play in the resultant formulation, for example, fillers, disintegrants, binders, lubricants and glidants. An added complexity is the fact that certain excipients can have different functional roles in different formulation types. Thus, lactose is widely used as a filler or diluent in solid oral dosage forms, for example, tablets and capsules [2] and as a carrier for inhalation products [3]. 

The quantity of barley starch produced around the world is very little when compared to starch production from corn, wheat, rice, potato or tapioca. There are only a few processing plants around the world that produce starch concentrate or purified starch from barley. Barley starch concentrates containing up to —78% (dry basis) starch are now produced in North America by milling and air-classification of barley grains. Milling disintegrates the grain into fine particles and air-classification separates them on the basis of differences in density, mass and projected area in the direction of air... 

Table 1 Classification of super disintegrants (partial listing)...

The Committee decided that in cases where the disintegration time is less than 10 minutes (non-rifampicin-containing products), a dissolution test would normally not be necessary depending on the biopharmaceutics classification system (BCS) category. 

With regard to their formation process and size, aerosol particles can be divided into two distinct groups fine and coarse particles (Whitby, 1978). Fine particles with radius smaller than 0.5-1.0 /im are formed by condensation and coagulation (see Subsection 4.2.2), while coarse particles arise mostly from surface disintegration (see Subsection 4.2.1). Since this classification provides an explanation of the form of the particle size distribution, we will discuss Whitby s ideas in more detail in Subsection 4.3.2. 

In some doublet reactions the same products may be obtained from the same reactants but in different ways. Such reactions were referred to as olistomeric and the structural conditions of their appearance were determined on the basis of the multiplet theory (348). Thus, theoretically two cases of bond fission can take place in esterification, HO—COR + H—OR and H—OCOR HO—R. The tracer method shows that the first case is realized as a rule. The half-doublet scheme expresses such experiments. The doublet indexes for the reactions in solutions disintegrate into such schemes see Balandin (37). A complete system of doublet reactions for C, H, N, 0, S, and Cl (without their isotopes) has been obtained by the author (345). It is much more detailed than Table VII and amounts to 1500 types. It was obtained by exhaustive variation of atoms and bonds in the index by means of a specially developed method based on matrix algebra and combinatorial analysis. The significance of the obtained classification for organic catalysis is similar to that of the complete system of forms in crystallography, which was derived from the groups of symmetry by Fedorov and covers all possible forms (349). 

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