湖北快三走势:AquaSolve? hypromellose acetate succinate (hydroxypropylmethylcellulose acetate succinate or HPMCAS)
Chemistry: CellulosicsSDS Link >
北京快三开奖结果彩票控 www.8hib.cn AquaSolve™ HPMCAS for pharmaceutical applications is a cellulosic polymer with four substituents randomly substituted on the available hydroxyl groups with the following mass content: methoxyl, 12–18 wt%; hydroxypropoxy, 4–23 wt%; acetyl, 2–16 wt% and succinoyl, 4–28 wt%. It is white to off-white in color and has a faint acetic acid-like odor and a barely detectable taste.
AquaSolve HPMCAS is available in several grades for pharmaceutical applications varying in extent of substitution of acetyl and succinoyl groups, and in two particle sizes (fine or granular). AquaSolve HPMCAS is used as a polymeric carrier in solid dispersions for solubility enhancement of poorly soluble drugs. The amphiphilic nature, high glass transition temperature (Tg) and low viscosity in various solvents of this polymer are some of the unique properties that make it ideal for use in spray-dried dispersion formulations.
In oral pharmaceutical formulations, AquaSolve HPMCAS is commonly used as an enteric film coating for tablets, capsules or granules. For aqueous film-coating purposes, a dispersion of HPMCAS fine powder and a plasticizer (such as triethyl citrate) in water is commonly used. Organic solvents are also vehicles for applying this polymer as a film coating. HPMCAS can form films without the addition of water or solvents.
Other pharmaceutical applications include its use alone or in combination with other soluble or insoluble binders in the preparation of granules with sustained drug-release properties, where the release rate is pH-dependent.
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