PART 2 (MODULE 2)

• Topical semisolid dosage forms - are normally presented in the form of creams, gels, ointments, or pastes.
• topical semisolid dosage form - hey contain one or more active ingredients dissolved or uniformly dispersed in a suitable base and any suitable excipients such as emulsifiers, viscosity increasing agents, anti microbial agents, antioxidants’, or stabilizing agents.
• Semisolid dosage forms - contain very limited quantities of a liquid or aqueous phase.
• Semi-solid dosage form - its surface pH should be tested during manufacturing for monitoring batch-to-batch uniformity and quality control of dosage forms
• Surface pH - can be measured by using a simple pH meter or by using a probe-type pH meter.
• Semisolid dosage forms - are plastic in behavior hence they retain their shape on application of outside force.
• Semi solid dosage form - has a wide range of raw materials that are available for the preparation
• semisolid dosage forms - are generally complex formulations having complex structural elements.
• Semi solid dosage form - they are composed of two phases (oil and water), one of which is a continuous (external e.g. suppositories and pessaries) phase, and the other of which is a dispersed (internal e.g. cream, ointment, paste) phase.
• dosage form - its physical properties will depend upon various factors, including the size of the dispersed particles, the interfacial tension between the phases, the partition coefficient of the active ingredient between the phases, and the product rheology. These factors combine to determine the release characteristics of the drug, as well as other characteristics, such as viscosity.
• Advantage of semi-solid dosage form:

  • It is used externally

  • Probability of side effect can be reduce

  • Local action

  • First pass gut and hepatic metabolism is avoided.

  • Patient compliance is increased, the drug termination is problematic cases is facilitated as compared with other routes of drug

  • administration.
• Disadvantages of semi-solid dosage form:

  There is no dosage accuracy in this type of dosage form

  The base which is used in the semi-solid dosage form can be easily oxidized.

  If we go out after using semi-solid dosage form problems can occur
• Ointments - are homogenous, semi-solid preparations intended for external application to the skin or mucous membrane.
• Ointments - are used as emollients or for the application of active ingredients to the skin for protective, therapeutic, or prophylactic purpose and

  where a degree of occlusion is desired.
• Ointments - are semisolid preparations for external application to skin or mucous membranes. Their composition softens but does not melt upon application to the skin.
• ointments - its therapeutically function as skin protectives and emollients, but they are used primarily as vehicles for the topical application of drug substances.
• Different type of semi-solid:

  1. Hydrophobic ointments
  2. Water-emulsifying ointments
  3. Hydrophilic ointments
  4. Creams
  5. Gels
  6. Hydrophobic gels (oleogen)
  7. Hydrophilic gels (hydrogel)
• Pastes - are homogeneous, semi-solid preparations containing high concentrations of insoluble powdered substances (usually not less than 20%) dispersed in a suitable base.
• Hydrophilic gels (hydrogel) - bases usually consist of water, glycerol, or propylene glycol gelled with suitable agents such as tragacanth, starch, cellulose derivatives, carboxyvinyl polymers, and magnesium aluminium silicates.
• Hydrophobic gel (oleogel) bases usually consist of liquid paraffin with polyethylene or fatty oils gelled with colloidal silica or aluminium or zinc soaps.
• Gels are usually homogeneous, clear, semi-solid preparation consisting of a liquid phase within a three-dimensional polymeric matrix with physical or sometimes chemical cross linkage by means of suitable gelling agents.
• Gels - are semisolid systems that consist of either suspensions of small inorganic particles or large organic molecules interpenetrated by a liquid.
• Creams - are homogeneous, semi-solid preparations consisting of opaque emulsion systems.
• Creams - Their consistency and rheological properties depend on the type of emulsion, either water-in-oil (w/o) or oil-in –water (o/w), and on the nature of the solids in the internal phase.
• Creams - are intended for the application to the skin or certain mucous membranes for protective, therapeutic, or prophylactic purposes, especially where an occlusive effect is not necessary.
• Hydrophilic ointment bases are miscible with water. The bases are usually mixture of liquid and solid polyethylene glycols (macrogols).
• Water-emulsifying ointments can absorb large amounts of water.
• Water-emulsifying ointments:They typically consist of a hydrophobic fatty base in which a w/o agent, such as wool fat, wool alcohols, sorbitan esters, mono glycerides, or fatty alcohols can be incorporated to render them hydrophilic.
• Water-emulsifying ointments - They may also be w/o emulsions that allow additional quantities of aqueous solutions to be incorporated. Such ointments are used especially when formulating aqueous liquids or solutions.
• Hydrophobic (lipophilic) ointments are usually anhydrous and can absorb only small amounts of water.
• Hydrophobic ointments - these typical bases used for their formulation are water-insoluble hydrocarbons such as hard, soft and liquid paraffin, vegetable oil, animal fats, waxes,

  synthetic glycerides and polyalkyl siloxanes.
• pastes - are usually less greasy, more absorptive, and stiffer in consistency than ointments because of the large quantity of powdered ingredients present.
• pastes - consist of a single phase, such as hydrated pectin, and others consist of a thick, rigid material that does not flow at body temperature.
• pastes - should adhere well to the skin. In many cases they form a protective film that controls the evaporation of water.
• Pastes - are semisolid dosage forms that contain one or more drug substances incorporated in a base with large proportions of finely dispersed solids.
• poultices - is an ancient form of topical medication also known as a cataplasma.
• Poultices - It is a soft mass of vegetable constituents or clay, usually heated before application.
• Kaolin poultice BP - is prepared by mixing and heating dried, heavy kaolin and boric acid with glycerine.
• part 1: classification of dosage forms: ROA = dosage form (uses, physical state, site of application)

  Route of administration:

  oral:

  1. powders
  2. tablets
  3. capsules
  4. suspensions
  5. solutions
  6. emulsions
  7. elixirs
  8. syrups
  9. magmas
  10. cachets
  11. gels
  12. pills

  parenteral:

  1. solutions
  2. suspensions
  3. emulsions

  transdermal:

  1. ointments
  2. powders
  3. creams
  4. lotions
  5. pastes
  6. plasters

  intro ocular:

  1. solutions
  2. suspensions
  3. ointments
• Part 2: classification of dosage forms: ROA = dosage form (uses, physical state, site of application)

  concjuntival

  1. ointments

  vaginal

  1. suppositories
  2. tablets
  3. ointments
  4. creams
  5. douches

  sublingual

  1. tablets
  2. lozenges

  intra nasal

  1. solutions
  2. sprays
  3. inhalations

  rectal

  1. suppositories
  2. enemas
  3. ointments

  intra respiratory

  1. aerosols

  urethral

  1. suppositories