Disintegrant is the most vital excipient in pharmaceutical formulations. The process by which a solid oral dosages form such as tablet breaks down into small particles is called disintegration. Oral solid dosage form such as tablets, capsule, beads, pellet and, granules need to break down into small particles to a rapid release of the drug so that the drug is readily available to dissolve in gastrointestinal fluid. According to USP-NF, disintegration time must be 15 minutes for core tablets, 30 minutes for film-coated tablets and hard gelatin capsules. Certainly, to maintain proper disintegration time a formulator will be used a disintegrant.
What is disintegrating agents or disintegrators or disintegrants?
Disintegrating agents or disintegrators or disintegrants are the substances which are added to an oral solid dosage form such as tablet, beads, pellet, granule as well as capsule to promote its rapid disintegration or break down into small particles after administration for facilitating rapid dissolution into GI fluid.
Classification of Disintegrants
Disintegrants are classified into two groups:
- Traditional Disintegrants: such as Starch, Microcrystalline Cellulose, and Sodium Alginate etc.
- Super Disintegrants: such as Crospovidone (cross-linked povidone), Croscarmellose Sodium (cross-linked cellulose) and Sodium Starch Glycolate (cross-linked starch) etc. At this time, these 3 super disintegrants are the most widely used disintegrant in pharmaceutical preparations. Most noteworthy , super disintegrants can swell up 10 fold with 30 seconds.
Further, Super disintegrants are two types:
- Natural Super disintegrants.
- Synthetic Super disintegrants
Generally, disintegrating agents are added before or after wet granulation and/or both in many cases. When disintegrating agents come into contact with a fluid/water either they swell up or wicking and then break down, thus facilitating dissolution.Probably, disintegrants acts by the following one or more mechanisms:
- By Swelling
- Due to heat of wetting
- Capillary action (wicking)
- Enzymatic reaction
- Due to the release of gases
- Combination action
- Electrostatic repulsion
- Chemical reaction
List of Disintegrants used in pharmaceutical preparations:
|Name of Disintegrants||Concentration|
|1. Calcium Alginate & Calcium Sodium Alginate||<10%|
|2. Calcium carboxymethylcellulose / calcium cellulose glycolate / carmellosum calcium||1–15%|
|3. Microcrystalline Cellulose||5–15%|
|4. Powdered Cellulose||5–20%|
|5. Chitosan Hydrochloride||—-|
|6. Corn Starch and Pregelatinized Starch||—-|
|7. Crospovidone (commercial name- Kollidon)||2–5%|
|8. Docusate Sodium||≈ 0.5%|
|9. Low-Substituted Hydroxypropyl Cellulose||—-|
|10. Hydroxypropyl Starch||—-|
|11. Magnesium Aluminum Silicate||2-10%|
|13. Sodium Alginate||2.5–10%|
|14. Starch||3–25% w/w|
|15. Pregelatinised Starch||5–10%|
|16. Sodium Starch Glycolate (Commercial name Primogel, Explotab)||2-8%, Optimum concentration is about 4%, although 2% is sufficient in many cases.|
|17. Croscarmellose Sodium (Commercial name Ac-Di-Sol)||10–25% in capsules and 0.5–5.0% in tablets.
Normally, Croscarmellose sodium at concentrations up to 5% w/w may be used as a tablet disintegrant. 2% w/w is used in direct compressed tablets and 3% w/w in wet-granulation processed tablets.
- Rowe, R. C., Sheskey, P. J., Owen, S. C., & American Pharmacists Association. (2006). Handbook of pharmaceutical excipients. London: Pharmaceutical Press.
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