Suspending agents gelatin

Common suspending agents are poly(vinyl alcohols) of various molecular weights and degrees of hydrolysis, starches, gelatin, calcium phosphate (especially freshly precipitated calcium phosphate dispersed in water to be used in the preparation), salts of poly(acrylic acid), gum arabic, gum tragacanth, etc. 

EDTA is also used to sequester polyvalent cations which may cause the cross linking of some suspending agents, thus leading to increased viscosity of gelatin [6],... 

Suspending agents carboxymethylcellulose, methylcellulose, gelatin, sorbitol. 

Purified gelatin Base, stabilizer, suspending agent, vehicle iv, im, sc... 

In soft gelatin capsules, powdered cellulose may be used to teduce the sedimentation rate of oily suspension fills. It is also used as the powder base material of powder dosage forms, and as a suspending agent in aqueous suspensions for peroral delivery. It may also be used to reduce sedimentation during the manufacture of suppositories. 

Typical suspending agents for the vinyl acetate polymerization are poly(vinyl alcohol) [particularly a grade represented as approximately 88% hydrolyzed poly(vinyl acetate)], gum arabic, hydroxyethyl cellulose, methyl cellulose, starches, sodium polyacrylate or sodium polymethacrylate, gelatin, and an equimolar copolymer of styrene and maleic anhydride neutralized with either sodium hydroxide or aqueous ammonia. Water-insoluble dispersing agents or... 

An efficient suspen.sion also requires a. suspending agent, normally a protective hydrophilic colloid, used in low concentration to avoid significant viscosity increases in the suspension, as compared to that on water. Very viscous vehicles provoke painful injections the same can be said about suspensions formed by too large particles. The most frequently used colloidal protectors are sodium car-boxymethylcellulose, potyvinylpyrrolidine. polyvinyl alcohol, or gelatin. These are all first choice when a new formulation is designed however, for very insoluble panicles like hydrocortisone butyl acetate or prednisolone butyl acetate, sorbitol has proven useful. 

Chem. Descrip. PEG-6 NF, FCC CAS 25322-68-3 EINECS/ELINCS 220-045-1 Uses Pharmaceuticals (carrier tor ointments for antiseptics and other medicaments, plasticizer in tablet coatings, base for suppositories, carrier, solvent, suspending agent in liq. preps., vehicle in gelatin capsules) thickener defoamer in fermentation and foal processing Properties Clear vise, liq. sol. in water m.w. 300 sp.gr. 1.125 dens. 9.36 Ib/gal f.p. -IOC vise. 69cSt flash pt. (PMCC) >400 F ref. index 1.463 sp. heat 0.508 cal/g/°C... 

Hypromellose or hydroxypropylmethylcellulose (HPMC) is a semisynthetic, inert, viscoelastic polymer, which is used as an ophthalmic lubricant, an excipient and controlled delivery component in oral medicaments and is found in a variety of commercial products [111]. Hypromellose is used as an alternative to animal gelatin and as an emulsifier, thickener, and suspending agent. 

The most commonly used suspending agents are cellulose derivatives, poly-aciylate salts, starch, poly(vinyl alcohol), gelatin, talc, and clay derivatives (95). The important function these agents must serve is to prevent the coalescence of monomer droplets during the course of the polymerization (114). Thickeners can also be added to improve suspension quality (95). Other additives such as lauryl alcohol, stearyl acid or cetyl alcohol lubricants and di- or trivinyl benzene, dial-lyl esters of dibasic acids, and glycol dimethacrylates cross-linkers are used to improve bead imiformity and bead performance properties. 

Besides sodium poly (aery late), other suggested suspending agents are sodium isopropylnaphthalene sulfonate, talc, gelatin, gum tragacant, water-soluble starches, barium sulfate, and other inorganic colloids or powders. 

The use of poly(vinyl alcohol) or gelatin as the suspending agent is said to lead to resins with rather low absorption capacity for plasticizer [89]. 

Use of triethylboron and methyl ethyl ketone peroxide, gelatin, and a nonionic suspending agent in the suspension polymerization of VCM [251]. 

The development of this technique was based on early experiences with the use of injection techniques. As a result of a perceived putative efficacy, attention was directed to the identification of inert, biocompatible substances that might safely function as bulking agents at the LES. An early report in 2001 by Feretis described a technique of endoscopic submucosal injection of polymethylmethacrylate microspheres suspended in gelatin into the LES of ten patients. At 7 months follow-up, there was a significant fall in 24-hour acid exposure (24.5% to 7.2%) that was, in addition, supported by a comparable improvement in symptom scores. 

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