Suspending agents methylcellulose

Cellulose (Figure 8.19) may be extracted from wood pulp, and is usually partially hydrolysed with acid to give microcrystalline cellulose. These materials are used as tablet diluents. Semi-synthetic derivatives of cellulose, e.g. methylcellulose, hydroxymethylcellulose, and carboxymethylcellulose, are used as emulsifying and suspending agents. Cellulose acetate phthalate is cellulose with about half the hydroxyl groups acetylated, and the remainder esterified with phthalic acid. It is used as an acid-resistant enteric coating for tablets and capsules. 

Suspending agents carboxymethylcellulose, methylcellulose, gelatin, sorbitol. 

Methylcellulose (stabilizer/suspending agent) Intestinal upset [7]... 

Nevertheless, simpler suspending and flavouring agents can also be prepared at the dispensary (e.g. methylcellulose 1%, or other celluloses such as hypromellose, microcrystalline cellulose, sodium carboxy-methylcellulose at 1-2%, xanthan gels, pharmacopoeial syrups, or mixtures of the above). In some formulations suspending agents may not be required, for example, when it is known that the drug is soluble... 

Methylcellulose solution was chosen as the suspending agent and was used exclusively throughout the study. 

Gantrez AN-119 Hydroxypropyl methylcellulose phthalate Kelzan XC Kelzan Klucel E Klucel G, H, J, M Klucel L Luviskol K12 Luviskol K17 Luviskol K30 Luviskol K60 Luviskol K80 Luviskol K90 Polyacrylamide PVP K-15 Solution PVP K-15 PVP K-30 PVP K-60 PVP K-90 Solution PVP K-90 PVP K-120 TIC Pretested Colloid 488T Powder TIC Pretested Colloid 602 Powder suspending agent, adhesives/seal-ants... 

Hypromellose is also used as a suspending and thickening agent in topical formulations. Compared with methylcellulose, hypromellose produces aqueous solutions of greater clarity, with fewer undispersed fibers present, and is therefore preferred in formulations for ophthalmic use. Hypromellose at concentrations between 0.45-1.0% w/w may be added as a thickening agent to vehicles for eye drops and artificial tear solutions. 

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