Chemistry of excipients derived from natural products

• What are some examples of excipients used in pharmaceuticals?

  Diluents/fillers, disintegrants, solvents, surfactants/emulsifiers, lubricants/glidants, preservatives, coatings, flavourings, and colouring
• What are the ideal features of excipients in pharmaceuticals?

  • Cheap
  • Biologically inert (no physiological effect)
  • Chemically inert (no reaction to API)
  • Able to provide a range of physico-chemical properties
• What is lactose and how is it formed?

  Lactose is a disaccharide formed via condensation of galactose and glucose
• What percentage of oral permeation in pharmaceuticals contains lactose?

  Approximately 60-70%
• What are the primary uses of lactose in pharmaceuticals?

  Lactose is mainly used as a filler and/or binder
• What is a disadvantage of lactose as an excipient?

  It is quite a poor lubricant
• What is cellulose and how is it structured?

  Cellulose is a long linear polymer of β-1,4-linked β-glucan units
• How can cellulose be modified?

  Cellulose can be modified to create a wide range of physico-chemical properties
• How is microcrystalline cellulose prepared?

  It is prepared by treating cellulose with 2.5M HCl at 105° for several hours
• What is the physical form of microcrystalline cellulose?

  It is a non-porous, free-flowing powder
• What is a key property of microcrystalline cellulose?

  It has high compressibility and gives a strong compact
• What are the types of cellulose ethers and their properties?

  • Methylcellulose: Swells in cold water, forms a clear viscous solution, acts as a bulk-forming laxative.
  • Ethyl cellulose: Insoluble in water, soluble in organic solvents, used as a tablet binder.
  • Hydroxyethyl cellulose: Soluble in water, forms a clear viscous solution, used as thickeners and suspending agents.
• What is the use of methylcellulose in pharmaceuticals?

  Methylcellulose is useful as a thickener and acts as a bulk-forming laxative in large doses
• What is ethyl cellulose and its solubility characteristics?

  Ethyl cellulose is insoluble in water but soluble in THF, methyl acetate, chloroform, and numerous alcohol mixtures
• What is the primary use of ethyl cellulose in pharmaceuticals?

  It is used as a tablet binder where an organic soluble binder is required
• What is hydroxyethyl cellulose's solubility in water and organic solvents?

  It is soluble in water to give a clear viscous solution and insoluble in most organic solvents
• What is cellulose acetate phthalate and its solubility characteristics?

  Cellulose acetate phthalate is insoluble in water and ethanol but soluble in acetone and dioxane
• What is the use of cellulose acetate phthalate in pharmaceuticals?

  It is used as an enteric coating
• What is cellulose acetate and its solubility characteristics?

  Cellulose acetate is highly flammable and insoluble in water, but soluble in some organic solvents
• What are the components of starch and their proportions?

  Starch is composed of approximately 20% amylose and 80% amylopectin
• What is alginic acid and where is it obtained from?

  Alginic acid is obtained from brown seaweeds
• What is the use of sodium alginate in pharmaceuticals?

  Sodium alginate is used as a stabilizer in emulsions
• What form can calcium alginate take and its application?

  Calcium alginate can be formed as fibers and woven into fabric for absorbable haemostatic dressing