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38 March 2015 Tablets & Capsules The physical properties of the resulting silica vary depending on the exact conditions under which the precipitation reaction takes place. Changes in temperature, pH, con- centration of the solutions used, ratio of the ingredients, and rate of mixing can be used to alter the silica particles' physical properties. Manufacturers manipulate these conditions to obtain specific properties, such as particle size, shape, and porosity. Table 2 lists some of the common pharmaceutical grades of precipitated silica. Suppliers include Evonik In - dustries, W.R. Grace, and Huber En - gineered Materials. These and other companies also offer precipitated sil- ica in nutraceutical, food, cosmetic, and technical grades. Both fumed silica and precipitated silica are essentially non-toxic and non-irritating. Inhalation of the dust particles may cause respiratory irrita- tion and, when handled in large quan tities, these silicas irritate the eyes and skin. Unlike crystalline sil- ica, synthetic amorphous silica does not cause silicosis from dust inhala- tion. However, gloves, eye protection, a res-pirator or dust mask, and pro- tective clothing should be used when handling. These materials are GRAS- listed and included in the FDA's Inactive Ingredient Database for use in oral solid dosage forms, suspen- sions, transdermals, suppositories, and vaginal preparations. Hydrophobic silica Hydrophobic silica (CAS# 68611- 44-9) is also known as silica dimethyl silylate, hydrophobic colloidal silica USP/NF, hydrophobic colloidal an - hydrous silica BP, and silica, hy dro - phobic colloidal Ph.Eur. This synthe - tic material is prepared by hy dro gen oxygen flame hydrolysis of silicon tetrachloride at 1,800°C, after which it is treated with dichlorodimethyl si - lane. The resulting dimeth yl silyl groups on the silica's surface render it hydrophobic. The presence of di - methyl silyl groups does not, however, alter the primary particle size or sur- face area of the silica. Hy drophobic fumed silica is thus water-repellent and will not disperse in water like the TABLE 1 Properties of some pharmaceutical grades of fumed silica Property Aerosil 200 Cab-O-Sil Aerosil 200 Aeroperl 300 Pharma a M-5P b VV Pharma a 300 Pharma c Particle size 0.012 primary 0.250 aggregate 0.012 primary 30 granulated (microns) Tap density 0.05 0.04 0.12 0.28 (g/cc) Specific surface area 200 200 200 300 (m 2 /cc) Oil adsorption NA 3.5 NA 1.5 (mL/g) pH 3.5-5.5 3.5-4.5 3.5-5.5 3.5-5.5 Pore volume 0.29 NA 0.31 2.55 (ml/g) Application Glidant Glidant Glidant Tableting aid Tableting aid Tableting aid Liquid carrier Anticaking agent Anticaking agent Anticaking agent Moisture-activated Tablet coating Liquid carrier Tablet coating dry granulation Drug carrier Tablet coating Drug carrier Drug carrier Disintegrant Drug carrier Disintegrant Adsorbent Adsorbent Disintegrant Adsorbent Spray drying agent Adsorbent Notes: a Aerosil is a trademark of Evonik Industries b Cab-O-Sil is a trademark of Cabot Corp. c Aeroperl is a trademark of Evonik Industries Silicified Microcrystalline Cellulose The Original Silicified MCC For free samples and a complete product listing, visit www.highfunctionalityexcipients.com 1-800-431-2457 VISIT US: 2015 ExcipientFest Americas BOOTH #08 April 28-29, 2015 Ritz Carlton San Juan, Puerto Rico Op Op Op Op Op Op O ti ti ti ti timi mi mi mize ze ze ze ze tab ab ab ab able le le le let t t t de de de de de deve ve ve ve ve velo lo lo lo lopm pm pm pm pm p en en en en ent t t an an an an and ma ma ma ma manu nu nu nu nufa fa fa fa fact ct ct ct ct ctur ur ur ur ur ure: e: e: e: e: e: e Op Op Op Op Op Op Op Op Op Op Op Op Op Opti ti ti ti ti ti ti ti ti ti timi mi mi mi mi mi mi mi mi mi m ze ze ze ze ze ze ze ze ze ze ze tab ab ab ab ab ab ab ab ab ab able le le le le le le le le le le le let de de de de de de de de de de de de deve ve ve ve ve ve ve ve ve ve ve ve v lo lo lo lo lo lo lo lo lo lo lo lopm pm pm pm pm pm pm pm pm pm pm p en en en en en en en en en en en en e t an an an an an an an an an an and ma ma ma ma ma ma ma ma ma manu nu nu nu nu nu nu nu nu nu nufa fa fa fa fa fa fa fa fa fa fact ct ct ct ct ct ct ct ct ct ct ct c ur ur ur ur ur ur ur ur ur ur ure: e: e: e: e: e: e: e: e: e • • • • • • Optimize tablet development and manufacture: • Excellent compactibility • High intrinsic flow • Enhanced lubrication efficiency • Improved blending properties • Greater production yields • Improved content uniformity