Starch tableting properties

Manudhane KS, Contractor AM, Kim HY, Shangraw RE Tableting properties of a directly compressible starch. / Pharm Set 1969 58 616-620. 

Afolabi, A.T. Olu-Owolabi, B. Kayode, O. Adebowale, O.K. Lawal, S.O. Akintayo, O.C. Functional and tableting properties of acetylated and oxidised finger millet (Eleusine coracana) starch. Starch/ Starke 2012, 64 (4), 326-337. 

Bouckaert et al. [42] tested buccal tablets of miconazole based on modified starch-polyacrylic acid mixtures. Although these tablets showed different mucoadhe-sion properties in vitro, no significant differences in the salivary content of miconazole could be observed in human volrmteers. 

Matsumara [23] noticed that starch particles exhibit slight exothermie properties during wetting, whieh was thought to cause localized stress resulting from the expansion of air retained in the tablet matrix. Unfortunately, this explanation, if valid, would be limited to a few substances such as aluminium silicate and kaolinite. List and... 

Te Wierik, G. H. P, Bergsma, J., Arends, A. W., Boersma, T., Eissens, A. C., Lerk, C. F. (1996). A new generation of starch products as excipient in pharmaceutical tablets. I. Preparation and binding properties of high surface area potato starch products. Int. J. Pharm., 134,27-36. 

Starch is extensively used due to its adsorbing properties. In dissolved form, it is used as a skin emollient and as an antidote for iodine poisoning. Other applications include the use as a tablet filler and binder and disintegrant. Sterilized starch is used as a lubricant for surgeon gloves. Unlike talc, it is completely adsorbed by body tissues. Soluble starch is prepared by treating commercial potato starch with dilute hydrochloric acid until it forms an almost clear solution in hot water. 

Starch is widely used in the food industry, and finds considerable applications in medicine. Its absorbent properties make it ideal for dusting powders, and its ability to swell in water makes it a valuable formulation aid, being the basis for tablet disintegrants. Soluble starch is obtained by partial acid hydrolysis, and is completely soluble in hot water. 

Sawayanagi et al. [301] reported the fluidity and compressibility of combined powders, viz., lactose/chitin, lactose/chitosan, potato starch/chitin, potato starch/chitosan as well as the disintegration properties of tablets made from these powders in comparison with those of combined powders of lactose/MCC and potato starch/MCC. This was done in order to develop direct compression dilutents as a part of their studies on pharmaceutical applications of chitin and chitosan. 

Like lubricants, glidants are fine powders and may be required for tablet compression at high production speeds to improve the flow properties of the material into the die or during initial compression stages. They are added in the dry state immediately prior to compression and, by virtue of their low adhesive potential, reduce the friction between particles. Colloidal silica is popular, as are starches and talc. 

Tablet diluent Inert substance used as filler to create desired bulk, flow properties, and compression characteristics in preparation of tablets Dibasic calcium phosphate, kaolin, lactose, mannitol, microcrystalline cellulose, powdered cellulose, precipitated calcim carbonate, sorbitol, starch...

Tablet glidant Agent used in tablet and capsule formulations to improve flow properties of powder mixture Colloidal silica, corn starch, talc...

The third class of lubricant activity is the antiadherent. Some materials have adhesive properties and can adhere to the punch surfaces during compression. This will induce tablet disorders sticking, with a film forming on the surface of the tablets, or picking, where solid particles from the tablet stick to the punch surface. Most die wall lubricants also have antiadherent actions, and in many formulations, the addition of a specific antiadherent will not be required separately. The antiadherent includes talc, maize starch, and microcrystalline cellulose. 

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