Colloidal microcrystalline cellulose

An aqueous base is the least expensive vehicle and poses no toxicity problems. A solution of the drug in water or water and cosolvent is made. Glycerin, glycols, natural and synthetic gums, and/or polymers are used to increase viscosity, cohesiveness, and plasticity. To overcome syneresis, or water separation in the gel, a common problem with aqueous bases, one can use absorbing materials such as microcrystalline cellulose, kaolin, colloidal silicon dioxide, starch, etc. 

Prosolv SMCC —silicified microcrystalline cellulose consisting of microcrystalline cellulose and colloidal silicon dioxide. 

Silicified microcrystalline cellulose is a synergistic, intimate physical mixture of two components microcrystalline cellulose and colloidal silicon dioxide (for further information see Cellulose, Microcrystalline and Colloidal Silicon Dioxide). Silicified microcrystalline cellulose contains 2% w/w colloidal silicon dioxide. 

Cellulose Microcrystalline PC Colloidal water-miscible type differentiated from nondispersible form by size... 

The concept of stabilizing emulsions by solid particles (mechanical stabilization) was described (Oza and Frank, 1986) tor colloidal microcrystalline cellulose (CMCC) that is adsorbed in a solid form onto oil droplets at the interface of a W/O emulsion with improved stability. Khopade and Jain repeated use of a similar process and managed to stabilize W/OAV emulsions by using MCC (microcrystalline colloidal cellulose) particles at both interfaces (Khopade and Jain, 1998). The droplets were small, and the yield of the multiple emulsion was fairly good. The increasing concentration of MCC in either internal or external phase increased droplet sizes. These systems showed promise in tuberculosis therapy. 

For suspensions primarily stabilized by a polymeric material, it is important to carefully consider the optimal pH value of the product since certain polymer properties, especially the rheological behavior, can strongly depend on the pH of the system. For example, the viscosity of hydrophilic colloids, such as xanthan gums and colloidal microcrystalline cellulose, is known to be somewhat pH- dependent. Most disperse systems are stable over a pH range of 4-10 but may flocculate under extreme pH conditions. Therefore, each dispersion should be examined for pH stability over an adequate storage period. Any... 

Shotton et al. [38] Van Kamp et al. [39] Sulfadiazine (D) Povidone (B) No filler Prednisone (D) Maize starch Na calcium alginate Alginic acid Microcrystalline cellulose Colloidal aluminum silicate Extra > intra Extragranular incorporation yielded fastest disintegration, but intragranular incorporation yielded finer particles. Equal distribution of disintegrants is recommended. 

Indeed, recently SEDDS themselves have been delivered as liquids absorbed onto powders such as colloidal silicon dioxide or microcrystalline cellulose (Nazzal et al., 2002). Selection of the absorbent was obviously critical to the performance of the system but, as an aside, it seems that this approach negates the rapid release properties of a SEDDS. It will be interesting to follow the future of this technology. 

Avicel RC and CL are water-dispersible, colloidal, microcrystalline cellulose products made for use in liquid preparations. Avicel RC and CL are coprocessed mixtures of microcrystalline cellulose and sodium carboxymethylcellulose. The amount of NaCMC can be determined using the IC method. About 10 g of Nasonex and about 25 mg of NaCMC NF are separately refluxed with 30 mL of glacial acetic acid for 2 h. The refluxed mixture is transferred to a 100-mL volumetric flask and diluted to volume with purified water, and mixed. The ion chromatograph (IC) was equipped with a suppressed conductivity detector, a 4-mm CSRS suppressor, current at 50 mA, a 250 mm x 4-mm Ion CS 12A column and a 50 mm x 4 mm Ion CG 12A guard column. The mobile phase is 0.13% methanesulfonic acid in water with a flow rate of 1 mL/min. Equal... 

Each 5 mL of VANTIN oral suspension contains cefpodoxime proxetil equivalent to 50 mg or 100 mg of cefpodoxime activity after constitution and the following inactive ingredients artificial flavorings, butylated hydroxy anisole, carboxymethylcellulose sodium, microcrystalline cellulose, carrageenan, citric acid, colloidal silicon dioxide, croscarmellose sodium, hydroxypropylcellulose, lactose, maltodextrin, natural flavorings, propylene glycol... 

Microcrystalline cellulose (MCC) is obtained by a controlled acid treatment intended to destroy the molecular bonding in the amorphous zones of cellulose. Usually HC1 or H2SO4 are used at 110°C for 15 min over native cellulose or regenerated cellulose. Colloidal gels are thus obtained showing thixotropy. MCC is used in the preparation of pharmaceutical compressed tablets due to its binding and disintegration properties. 

In natural cellulose, the microcrystals are packed tightly in the fiber direction in a compact structure resembling bundles of wooden match sticks placed side by side. Unhinging the interconnecting chains by acid treatment does not destroy this structure. However, the unhinged crystals are now free to be dispersed by mechanical disintegration.. . . We immediately set out to explore this new avenue, developing uses for colloidal dispersions of microcrystalline celluloses, known commercially as Avicel. 

Durasolv (CIMA Labs Inc.) Zomig ZMT Zolmitriptan (2.5mg), mannitol, microcrystalline cellulose, crospovidone, aspartame, sodium bicarbonate, citric acid, anhydrous, colloidal silicon dioxide, magnesium stearate, orange flavor Compression... 

Physical interactions between drug and excipient also can compromise quality. Adsorption of drug by microcrystalline cellulose resulted in drug dissolution being less than complete. Interaction between chloramphenicol stearate and colloidal silica during grinding led to polymorphic transformation. 

Suspending agent systems such as a pseudoplastic (sodium carboxymethylcellulose) in combination with a clay (hydrated colloidal magnesium aluminum silicate) or blends and coprecipitates of sodium carboxymethylcellulose and microcrystalline cellulose exhibit some thixotropic flow characteristics. Other pseudoplastics such as hydroxyethylcellulose or hydroxy-propyl methyl cellulose may be required to overcome possible in compatibilities with sodium carboxymethylcellulose. 

Silicified microcrystalline cellulose is a coprocessed mixture of microcrystalline cellulose and 2% colloidal silicon dioxide, which has improved flow and binding properties compared to microcrystalline cellulose itself. ... 

The colloidal silicon dioxide appears physically bound onto the surface and inside the silicified microcrystalline cellulose particles. Extensive studies using different spectroscopic methods have failed to show any form of chemical inter-action.<" ")... 

Since the colloidal silicon dioxide is physically bound to the microcrystalline cellulose the general recommendations of gloves, eye protection, and a dust mask should be followed when handling silicified microcrystalline cellulose. 

Silicified microcrystalline cellulose—co-processed microcrystalline cellulose that has been silicified with colloidal silicon dioxide... 

Polymeric thickeners Gums Acacia Alginates Carageenan Chitosan Collagen Tragacanth Xantham Celluloses Sodium carboxymethyl Hydroxyethyl Hydroxypropyl Hyd roxypro pyl m ethyl Acrylic acids Carbomers Polycarbophil Colloidal solids Silica Clays Microcrystalline cellulose Hydrogels Polyvinyl alcohol Polyvinylpyrrolidone Thermoreversible polymers Poloxamers... 

Colloidal, aqueous dispersions of microcrystalline cellulose can be prepared by boiling cotton linters for 15 minutes with 2.5 N hydrochloric acid, followed by subjecting the resulting (level-off D.P.) cellulose to vigorous mechanical agitation. The microcrystals ( Avicel ), which are thereby freed from their fibrous packed structure, have been put to a variety of uses in the production of food gels and structural materials. ... 

The preparation of microcrystalline cellulose by acid hydrolysis of native and regenerated fibers has been studied extensively (3) and developed into a commercial process by Battista et ah (4). The resulting products are used as aqueous gels with high water-bonding capacity, inert food and drug additives, viscosity regulators, and stabilizers in colloidal... 

Therefore, if when carrying out a preformulation study we wished to compare the effects of 4 diluents (e.g. lactose, calcium phosphate, microcrystalline cellulose, and mannitol), 3 disintegrants, 2 binders, 2 lubricants, and a glidant (e.g. presence or absence of colloidal silica), it is easy to verify that the model contains 14 coefficients (including the constant term), but only 9 of these are independent. 

Chloramphenicol stearate Milling in a Pulverisette 5 grinder (Fritsch) (agate mortar and balls) with colloidal silica or microcrystalline cellulose [102,103]... 

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