Disintegrants crospovidone

Tablets were prepared either with an insoluble (dicalcium phosphate dihydrate), a soluble (6-lactose) or a moderately soluble filler-binder (a-lactose monohydrate). As a disintegrant four different starches (com, rice, potato and tapioca) were used. As a comparison the effect of two super-disintegrants (crospovidone and sodium starch glycolate) was studied. The disintegrants were added at two concentration levels. The compression load was adjusted in order to obtain tablets with comparable initial cmshing strengths.

The crospovidones are easily compressed when anhydrous but readily regain their form upon exposure to moisture. This is an ideal situation for use in pharmaceutical tablet disintegration and they have found commercial appHcation in this technology. PVP strongly interacts with polyphenols, the crospovidones can readily remove them from beer, preventing subsequent interaction with beer proteins and the resulting formation of haze. The resin can be recovered and regenerated with dilute caustic. 

The ability of a disintegrant to draw water into the porous network of a tablet is essential for effective disintegration. For crospovidone, water wieking has been thought to be the main meehanism of disintegration. Komblum and Stoopak [5] ob-... 

No filler Crospovidone Equal > intra > extra fastest disintegration and dissolution. 

Hartauer et al. [58] reported that peroxide residues in povidone (binder) and crospovidone (disintegrant) were attributable to the formation of the A-oxide oxidation product of raloxifene. The authors correlated residual levels of peroxide in the excipients with A-oxide formation and thereby gained understanding of the degradation mechanism. A radical-initiated oxidation mechanism would be expected to show a typical S -shaped autocatalytic curve, whereas these curves showed fickian kinetics that is, rapid initial formation of the A-oxide followed by a plateauing of the rate, with consumption of the peroxides, leading to a slowing of the reaction rate. 

The four starches used in this study have been proven to be suitable tablet ingredients [19]. Both used super-disintegrants, Primojel (sodium starch glycolate) and Polyplasdone XL (crospovidone), are commonly used as a disintegrant in tablets prepared by direct compression. 

The initial disintegration times of the tablets prepared with a-lactose were excellent all tablets disintegrated within 2 minutes. The 6-lactose tablets showed longer, but still adequate disintegration times. The difference between the effectiveness of sodium starch glycolate and crospovidone in 6-lactose tablets was previously studied by Van Kamp et al. [24] and ascribed to the higher capillary action of crospovidone. 

Irrespective of the filler-binder used, in tablets prepared with crospovidone as a disintegrant, all three adjustable factors influenced the SIR of crushing strength. Also the interaction between the concentration and the relative humidity was significant (y0i3,siR(s) 0)-... 

Each combination behaves differently after storage. In all cases there was an effect of the starch concentration (y i sir(d) is significant). In most cases the relative humidity as well as the interaction between the relative humidity and the disintegrant concentration plays a role in the disintegration time of tablets prepared with either lactose. The dicalcium phosphate dihydrate/rice starch combination is influenced very strongly by the three factors studied. This combination is not suitable for use in tropical countries. Neither is the combination of B-lactose and crospovidone. 

From the SIR of disintegration time calculations no general conclusions can be drawn. It is merely possible to detect which specific combination is influenced strongly by the storage conditions. In this respect the dicalcium phosphate dihydrate/rice starch and the B-lactose/crospovidone combinations were conspicuous. These combinations should be avoided in formulations for use in tropical countries. 

Crospovidone Tablet disintegrant Sodium chloride Osmotic agent... 

Sodium starch glycolate, crospovidone, Disintegrant Hydration capacity, water uptake... 

Crospovidone, which is slightly cross-linked with bifunctional monomers (e.g., l-vinyl-3-ethylidenepyrrolidone, ethylene-bis-3-(N-vinyl-pyrrolidone), is obtained by popcorn polymerization. It has been used as a disintegration agent for tablets. 

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