Microcrystalline cellulose

• BPMicrocrystalline Cellulose
• JPMicrocrystalline Cellulose
• Ph. Eur.Cellulose, Microcrystalline
• USP–NFMicrocrystalline Cellulose

Avicel PH; Celex; cellulose gel; Emcocel; Ethispheres; Fibrocel; Pharmacel; Tabulose; Vivapur; E460(i)

Cellulose · [9004-34-6]

(C6H10O5)n, n ≈ 220 · ≈ 36 000

Diluent (filler), Binder, Disintegrant

Typical concentrations: 20–90% diluent/binder · 5–15% disintegrant · Dosage forms: Solid

Microcrystalline cellulose is one of the most widely used tablet and capsule diluents, in both wet granulation and direct compression. Besides acting as a filler and dry binder it has some lubricant and disintegrant properties, which makes it especially useful in direct compression. Typical concentrations: tablet binder/diluent 20–90%; capsule binder/diluent 20–90%; adsorbent 20–90%; antiadherent 5–20%; tablet disintegrant 5–15%. It is also used in cosmetics and foods.

A purified, partially depolymerised cellulose. White, odourless, tasteless, crystalline powder made up of porous particles. Commercial grades differ in particle size and moisture content, which govern their properties and uses.

Particle size (nominal mean)

≈ 50 µm (Avicel PH-101); ≈ 100 µm (PH-102); ≈ 180 µm (PH-200)

Density

bulk ≈ 0.32 g/cm³ and tapped ≈ 0.45 g/cm³ (PH-101); true 1.512–1.668 g/cm³

Moisture content

typically below 5% w/w; low-moisture grades below 1.5%

Melting point

chars at 260–270 °C

pH

5.0–7.5 (supernatant of a 12.5% w/v aqueous dispersion)

Solubility

slightly soluble in 5% w/v sodium hydroxide solution; practically insoluble in water, dilute acids and most organic solvents

Stable, although hygroscopic. Store the bulk material in a well-closed container in a cool, dry place.

Incompatible with strong oxidising agents.

Made by controlled hydrolysis of α-cellulose, obtained as a pulp from fibrous plant material, with dilute mineral acid. The hydrocellulose is purified by filtration and the aqueous slurry is spray-dried to give dry, porous particles of a broad size distribution.

Widely used in oral products and foods and regarded as relatively non-toxic and non-irritant. It is not absorbed systemically after oral administration. Very large quantities may have a laxative effect. Misuse of tablets by injection or inhalation has caused cellulose granulomas.

Observe normal precautions for the quantity handled. The dust may irritate the eyes; gloves, eye protection and a dust mask are recommended.

GRAS listed. Accepted as a food additive in Europe (E460). Included in the FDA Inactive Ingredient Database (inhalation; oral capsules, powders, suspensions, syrups and tablets; topical and vaginal preparations) and in non-parenteral medicines licensed in Europe.

Microcrystalline cellulose and carboxymethylcellulose sodium; powdered cellulose; silicified microcrystalline cellulose.

Choose the grade for the process: fine grades (PH-101) suit wet granulation, coarser grades (PH-102, PH-200) flow better in direct compression, and low-moisture grades (PH-112, PH-113) are used with moisture-sensitive drugs.