عبد الرحمن، عبد المجيدPregelatinised Starch Nonproprietary Names : 1. BP: Pregelatinised Starch 2. PhEur: Starch, Pregelatinised 3. USP-NF: Pregelatinized Starch Synonyms : Amylum pregelificatum; compressible starch; C*PharmGel; Instastarch; Lycatab C; Lycatab PGS; Merigel; National 78-1551; Pharma-Gel; Prejel; Sepistab ST200; Spress B820; Starch 1500 G;Tablitz; Unipure LD; Unipure WG220. Empirical Formula and Molecular Weight : (C6H10O5)n where n = 300–1000. Pregelatinized starch is a starch that has been chemically and/or mechanically processed to rupture all or part of the starch granules. Both fully and partially pregelatinized grades are commercially available. Partial pregelatinization renders the starch flowable and directly compressible. Full pregelatinization produces a cold-water soluble starch that can be used as a wet granulation binder. Typically, pregelatinized starch contains 5% of free amylose, 15% of free amylopectin, and 80% unmodified starch , Normally the fully pregelatinized starch contains 20–30% amylase and the rest amylopectin, which is about the same ratio (1 : 3) as for the partially pregelatinized form. There are ways to increase the amylose portion Structural Formula : See Starch. Functional Category : 1. Tablet and capsule diluents 2. tablet and capsule disintegrant 3. tablet binder. Although magnesium stearate 0. عبد الرحمن، عبد المجيد Applications in Pharmaceutical Formulation or Technology : Partially pregelatinized starch is a modified starch used in oral capsule and tablet formulations as a binder. pregelatinized starch is self-lubricating. diluent. Both partially and fully pregelatinized starch may also be used in wet granulation processes Fully pregelatinized starches can be used to make soft capsules. when it is used with other excipients it may be necessary to add a lubricant to a formulation. white to off-white colored powder. and disintegrant. and coatings as well as binders in tablets.25% w/w is commonly used for this purpose. stearic acid is generally the preferred lubricant with pregelatinized starch. Uses of pregelatinized starch Use Diluent (hard gelatin capsules) Tablet binder (direct compression) Tablet binder (wet granulation) Tablet disintegrant Concentration (%) 5–75 5–20 5–10 5–10 Description : Pregelatinized starch occurs as a moderately coarse to fine. . concentrations greater than this may have adverse effects on tablet strength and dissolution. It is odorless and has a slight characteristic taste. In comparison to starch. Therefore. However. shells. Partially pregelatinized starch is used in oral dry powder hard capsule formulations. In such processes. partially pregelatinized starch may be produced with enhanced flow and compression characteristics such that the pregelatinized material may be used as a tablet binder in dry-compression or direct compression processes. roll-dried. Pastes can be prepared by sifting the pregelatinized starch into stirred. Stability and Storage Conditions : Pregelatinized starch is a stable but hygroscopic material. median diameter 52 mm. Slightly soluble to soluble in cold water. Pharmaceutical grades of fully pregelatinized starch use no additives and are prepared by spreading an aqueous suspension of ungelatinized starch on hot drums where gelatinization and subsequent drying take place. In the last case. 5.516 g/cm3 Solubility : Practically insoluble in organic solvents. The resultant material is ground and the moisture content is adjusted to specifications. depending upon the degree of pregelatinization. عبد الرحمن، عبد المجيد Pharmacopeial Specifications : 1. theslurry may be spray-dried. . cold water. Partially pregelatinized starch is produced by subjecting moistened starch to mechanical pressure. Incompatibilities : _ Method of Manufacture : Food-grade pregelatinized starches are prepared by heating an aqueous slurry containing up to 42% w/w of starch at 62–728C. 2. 9. Flowability 18–23% Density (tapped) 0.6% Moisture content Pregelatinized maize starch is hygroscopic Particle size distribution 30–150 mm. dry place. 7. extruded. 4. pH : 4. which should be stored in a well-closed container in a cool. 8. After heating. 3. added to control rehydration or minimize stickiness during drying.5–7.0% Sulfated ash > 0. the dried material may be processed to produce a desired particle size range. Chemical additives that may be included in the slurry are gelatinization aids (salts or bases) and surfactants.0 Loss on drying > 15. 6. Cold-water-soluble matter for partially pregelatinized starch is 10–20%.879 g/cm3 Density (true) 1. or drum-dried. oral consumption of large amounts of pregelatinized starch may be harmful. . However. عبد الرحمن، عبد المجيد Safety : Pregelatinized starch and starch are widely used in oral solid-dosage formulations. See Starch for further information. Pregelatinized starch is generally regarded as a nontoxic and nonirritant excipient.