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SHIN-ETSU AQOAT® (HPMCAS)Hypromellose Acetate Succinate USP/NF, JPE
AQOAT is an enteric coating material which was first approved in Japan in 1987. Subsequently the product was approved in Korea, Europe and USA.
Hypromellose acetate succinate is manufactured from highly purified pulp and involves introduction of acetyl and succinoyl groups into the hydroxyl backbone of Hypromellose. Various grades of AQOAT are available which differ in the particle size and chemical substitution levels.
The polymer, Hypromellose acetate succinate, lends itself to use in different coating techniques - aqueous, solvent based, ammonia neutralization and dry / deposition coating. It can also be recommended in solid dispersions to enhance the bioavailability of poorly soluble drugs as well as in the design of controlled release dosage forms for targeting drug release to specific gastrointestinal sites.
| Grade | Description | Mean particle size
| Application
| | Dissolving pH* | Acetyl (%) /
Succinoyl (%) | Aqoat AS-LF | ≥ 5.5 | 8 / 15
| 5 μm | Micronized grades or aqueous and dry coating. | | Aqoat AS-MF | ≥ 6.0 | 9 / 11
| | Aqoat AS-HF | ≥ 6.5
| 12 / 7
| | Aqoat AS-LG | ≥ 5.5
| 8 / 15
| 1 mm
| Granular grades for solvent-based coating.
| | Aqoat AS-MG | ≥ 6.0 | 9 / 11
| | Aqoat AS-HG | ≥ 6.5
| 12 / 7
| * In Mcllvaine's buffer (citric acid‐Na2HPO4) and USP Phosphate Buffer (NaOH‐KH2PO4)
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