Excipient starches

An antidepressant in 10,20, and 40 mg doses Active ingredient Fluoxethine hydrochloride Excipients Starch, gelatin, silicone, titanium dioxide, iron oxide, etc. 

Shiftan, D., Ravanelle, F., Alexandre Mateescu, M., Marchessault, R. El. (2000). Change in V/B polymorphratioand T1 relaxation of epichlorohydrin cross-liked high amylose starch excipient. Starch, 52, 186-195. 

Excipients starch, gelatin, silicone, titanium dioxide, iron oxide etc. 

It is worth remarking that residual humidity can favor microbiological growth especially in some natural products used as excipients (starch, gelatine, etc.). From a physico-chemical point of view, residual humidity may have an impact on the hardness of the tablets as shown by Chowhan, Down and McMullen. ... 

The analysis of a pharmaceutical tablet (6) requires sample preparation that is little more complex as most tablets contain excipients (a solid diluent) that may be starch, chalk, silica gel, cellulose or some other physiologically inert material. This sample preparation procedure depends on the insolubility of the excipient in methanol. As the components of interest are both acidic and neutral, the separation was achieved by exploiting both the ionic interactions between the organic acids and the adsorbed ion exchanger and the dispersive interactions with the remaining exposed reverse phase. 

Normally, the lubricants present in the tableting mass also act as antiadherents, but in the worst cases it may be necessary to add more starch or even talc to overcome the defect. So by judicious choice of a combination of excipients, all of these undesirable effects of the tableting process can be minimized. 

The sorption of water by excipients derived from cellulose and starch has been considered by numerous workers, with at least three thermodynamic states having been identified [82]. Water may be directly and tightly bound at a 1 1 stoichiometry per anhydroglucose unit, unrestricted water having properties almost equivalent to bulk water, or water having properties intermediate between these two extremes. The water sorption characteristics of potato starch and microcrystalline cellulose have been determined, and comparison of these is found in Fig. 11. While starch freely adsorbs water at essentially all relative humidity values, microcrystalline cellulose only does so at elevated humidity values. These trends have been interpreted in terms of the degree of available cellulosic hydroxy groups on the surfaces, and as a function of the amount of amorphous material present [83]. 

Diffuse reflectance spectroscopy was used to screen the possible interactions between a large number of adjuvants and several dyes [23]. It was concluded that supposedly inert excipients (such as starch or lactose) were capable of undergoing significant reactions with the dyes investigated (Red No. 3, Blue No. 1, and Yellow No. 5). For adjuvants containing metal ions (zinc oxide, or calcium, magnesium, and aluminum hydroxides), the degree of interaction could be considerable. It was concluded from these studies that dye-excipient interactions could also be responsible for the lack of color stability in certain tablet formulations. 

Surface area and moisture uptake have been related to the disintegration properties of excipients such as crosspovidone, starch, and alginic acid [17]. The surface areas of the three materials were measured, and a linear correlation was found between the maximum moisture sorption and specific surface area for the three disintegrants. The greater the surface area of the material, the more numerous were the sites for capillary attraction of water to its surface. It was postulated that the capillary action appears to be responsible for the disintegration properties of the materials. 

The range of application of shear cell testing methodology is seen in Tables 2-6. Table 3 relates the flow properties of mixtures of spray-dried lactose and bolted lactose. These mixtures, in combination with the excipients tested, cover a broad range of flow. Tables 4 and 5, for example, show lot to lot variations in the flow properties of several materials, and Table 6 shows the variation in flow properties of bolted starch, sucrose, and phenacetin at different relative humidities (RH). Figure 8 presents the yield loci of sucrose at four different consolidation loads. Also shown in the figure are the shear indices determined at each consolidation load. 

Native starches are used as disintegrants, diluents, and wet binders. However, their poor flow and high lubricant sensitivity make them less favorable in direct compression. Different chemical, mechanical, and physical modifications of native starches have been used to improve both their direct compression and controlled-release properties (Sanghvi, 1993 van Aerde and Remon, 1988). Schinzinger and Schmidt (2005) used potato starch as an excipient and compared its granulating behavior with a-lactose-monohydrate and di-calcium phosphate anhydrous in a laboratory fluidized bed granulator using statistical methods. 

Korhonen, O., Raatikainen, R, Harjunen, R, Nakari, J., Suihko, E., Peltonen, S., Vidgren, M., Raronen, R. (2000). Starch acetates—multifunctional direct compression excipients. Pharm.lRes., 77(9), 1138-1143. 

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. 

Sanghvi, P. R, Collins, C. C., Shukla, A. J. (1993). Evaluation of Preflo modified starches as new direct compression excipients 1. Tabletting characteristics. Pharm. Res., 10, 1597-1603. 

The batch size ranged from 3.75 up to 60 kg. To obtain precise scale-up measurements, the excipients which were used belonged to identical lots of primary material [10% (W/W) corn starch, 4% (W/W) polyvinylpyrrolidone as binder, and 86% (W/W) lactose]. As can be seen from Figure 4, the amount of granulating liquid is linearly dependent on the batch size. During the scale-up exercise, the rate of addition of the granulation liquid was enhanced in proportion to the larger batch size. Thus the power profile, which was plotted... 

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