Name: Cellulose, Powdered
CAS No: Cellulose [9004-34-6]
BP: Powdered Cellulose JP: Powdered Cellulose PhEur: Cellulose, Powdered USP-NF: Powdered Cellulose
Alpha-cellulose; Arbocel; cellulosi pulvis; E460; Elcema; KC Flock; Microcel 3E-150; Sanacel; Sanacel Pharma; Sancel-W; Solka-Floc.
Cellulose [9004-34-6]
(C6H10O5)n 243 000 where n 500. Since cellulose is derived from a natural polymer, it has variable chain length and thus variable molecular weight.
Powdered cellulose is used as a tablet diluent and filler in two-piece hard capsules; see Table I. In both contexts it acts as a bulking agent to increase the physical size of the dosage form for formulations containing a small amount of active substance. Powdered cellulose has acceptable compression properties, although the flow properties of most brands are poor. However, low-crystallinity powdered cellulose has exhibited properties that are different from standard powdered cellulose materials, and has shown potential as a direct-compression excipient.(1) In soft gelatin capsules, powdered cellulose may be used to reduce the sedimentation rate of oily suspension fills. It is also used as the powder base material of powder dosage forms, and as a suspending agent in aqueous suspensions for peroral delivery. It may also be used to reduce sedimentation during the manufacture of suppositories. Powdered cellulose has been investigated as an alternative to microcrystalline cellulose as an agent to assist the manufacture of pellets by extrusion/spheronization.(2,3) However, powdered cellulose alone requires too much water and due to water movement during extrusion cannot be used as an extrusion/spheronization aid on its own.(4) Powdered cellulose is also used widely in cosmetics and food products as an adsorbent and thickening agent.
Powdered cellulose occurs as a white or almost white, odorless and tasteless powder of various particle sizes, ranging from a freeflowing fine or granular dense powder, to a coarse, fluffy, nonflowing material.
See Table II.
Angle of repose <628 for Arbocel M80; <498 for Arbocel P 290; <368 for Arbocel A 300. Density (bulk) 0.15–0.39 g/cm3 , depending on the source and grade. Density (tapped) 0.21–0.48 g/cm3 , depending on the source and grade. Density (true) 1.47–1.51 g/cm3 (5) depending on source and grade; 1.27–1.61 g/cm3 (6) depending on source and grade. Moisture content Powdered cellulose is slightly hygroscopic;(7) NIR spectra see Figure 3. Particle size distribution Powdered cellulose is commercially available in several different particle sizes; see Table III. Solubility Practically insoluble in water, dilute acids, and most organic solvents, although it disperses in most liquids. Slightly soluble in 5% w/v sodium hydroxide solution. Powdered cellulose does not swell in water, but does so in dilute sodium hypochlorite (bleach).
Powdered cellulose is a stable, slightly hygroscopic material.(7) The bulk material should be stored in a well-closed container in a cool, dry place.
Incompatible with strong oxidizing agents, bromine pentafluoride, sodium nitrite and fluorine.(6)
Powdered cellulose is manufactured by the purification and mechanical size reduction of a-cellulose obtained as a pulp from fibrous plant materials.
Powdered cellulose is widely used in oral pharmaceutical formulations and food products and is regarded as a nontoxic and nonirritant material. However, allergic reactions when inhaled, ingested or in contact with the skin are possible.(6) Powdered cellulose is not absorbed systemically following peroral administration and thus has little toxic potential. Consumption of large quantities of cellulose may, however, have a laxative effect, although this is unlikely to be a problem when cellulose is used as an excipient in pharmaceutical formulations. Deliberate abuse of formulations containing cellulose, either by inhalation or by injection, has resulted in the formation of cellulose granulomas.(8) LD50 (rat, oral): >5 g/kg (6) LD50 (rat, inhalation): 5.8 g/m3 /4 h (6) LD50 (rabbit, skin): >2 g/kg (6)
Observe normal precautions appropriate to the circumstances and quantity of material handled. Powdered cellulose may be an irritant to the eyes. The material emits toxic fumes under fire conditions and when heated to decomposition.(6) Gloves, eye protection, and a dust mask (NIOSH approved), and engineering controls such as exhaust ventilation are recommended. In the UK, the workplace exposure limits for cellulose have been set at 10 mg/m3 long-term (8-hour TWA) for total inhalable dust and 4 mg/m3 for respirable dust; the short-term limit for total inhalable dust has been set at 20 mg/m3 . (9) In the USA, the TWA exposure values are defined by NIOSH as 5 mg/m3 (respirable fraction) and 10 mg/m3 (total dust).(6)
GRAS listed. Accepted for use as a food additive in Europe (except for infant food in the UK). Included in nonparenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.
Cellulose, microcrystalline.
Powdered cellulose is one of the materials that have been selected for harmonization by the Pharmacopeial Discussion Group. For further information see the General Information Chapter <1196> in the USP32–NF27, the General Chapter 5.8 in PhEur 6.0, along with the ‘State of Work’ document on the PhEur EDQM website, and also the General Information Chapter 8 in the JP XV. When powdered cellulose was used as a tablet disintegrant, tablets could be stored up to 78% RH without losing their rapid disintegration properties.(10) Tablets disintegrating rapidly in the oral cavity were also successfully prepared with powdered cellulose.(11) Coprocessing of powdered cellulose with magnesium carbonate by roller compaction has resulted in a promising excipient for direct tableting.(12) Highly porous matrices from powdered cellulose may be suitable for stabilization and handling of liquid drug substances.(13) A specification for powdered cellulose is contained in the Food Chemicals Codex (FCC).(14) The EINECS number for powdered cellulose is 232-674-9.