Modified Release Tablet Coatings:
• Preparations which have been designed in such a way that the rate or place at which the active pharmaceutical ingredients are released has been modified (BP).
• Coating can be applied directly to the tablet or indirectly by coating small pellets before compression.
Enteric Coating:
• Enteric coating uses materials with solubility profiles dependent upon.
• Reasons for Enteric coating:
– to protect the tablet from the acidity of the stomach.
– to protect the stomach from an irritant effect of some drugs e.g. Aspirin.
– to specifically target drug absorption in the GI Tract “downstream” of the stomach.
• Enteric Sugar coating.
– the sealant includes an enteric polymer, other steps remain the same
• Enteric Film Coating.
– an enteric polymer is incorporated into the suspension.
– weight of suspension applied is more critical (and greater) than standard film coating.
• Enteric polymers include cellulose acetate phthalate, polyvinyl acetate phthalate and acrylates.
Related: Tablet Coating Problems and their Solutions in Pharmaceuticals
Related: Tablet Coating Problems and their Solutions in Pharmaceuticals
Controlled / Sustained
• Coating includes specialist materials which are insoluble but allow water to enter and the drug in solution to diffuse out.
• Designed to give uniform and sustained drug release at a rate determined directly by the coating thickness.
• Examples are modified ethylcelluloses.
No comments:
Post a Comment
Please don't spam. Comments having links would not be published.