Oral Dosage Forms Tablet Flashcards
What is the GI Transit of oral dosage
- Oral dosage
- Stomach pH 1.2
- Duodenum pH 4.5
- Jejunum pH 6.8
- Colon pH 7.5
- Elimination feces
Define tablet
1 or more drugs as well as a series of other subtances used in a formulation of a complete preparation
What are the types of tablets
-convensional compress (provide rapid disintegration and dissolve in gastric fluid)
-multiple compress (at least two layers)
-chewable (disintegrate in the mouth and rapid drug effect)
-effervescent (dropped in a glass of water)
-buccal and sublingual (held within oral cavity, fast disintegration and drug release)
-lozenges (dissolves slowly in mouth, released drug dissolved in saliva, slow release
-pastille (medicinal pill made of thick liquid that has been solidified, consumed by chewing)
-sugar coated (water soluble, protects enclosed drugs from environment, provides barrier to objectionable taste or odor)
-extend release (increase release time of drugs cause local irritation in stomach, one dose release for12-24 hours, Controlled release preparations)
-film coating (conventional tablets that have been coated with polymer or a mixture of polymers)
-enteric coating (coated with polymer that doesn’t dissolve under acidic conditions)
-cachets (rarely used in practice today, front rice flour, available in dry or wet seal, dipped with water and swallow whole, packed in cardboard boxes)
Compressed tablets
Manufactured with tablet machines capable of exerting great pressure in compacting the powdered or granulated material
Design of pharmaceutical tablets
-Prepared by compression method
-Shapes are determined
-Moulded tablets prepared on a large scale by ta let machinery or on a small scale by manually forcing dampened powder material into a mold
Formulations of tablet
-tablet is usually compressed
-contains 5-10% of drug (active substances)
-80% fillers, disintegrants, lubricants, glidants, binders
-10% of compounds ensure easy disintegration, disaggregation and dissolution
Characteristics of fillers
-chemically inert
-non-hygroscopic
-biocompatible
-good biopharmaceutical properties
-good technical properties
What is disintegrant
Ensure that the tablet when in contact with the liquid, breaks up into smaller fragments to promote drug dissolution
Steps:
1. Liquid wets solid to penetrate pores of tablet
2. Tablet breaks into fragments
Types:
-facilitate water uptake (facilitate transport of H2O into pores of tablet)
-rupture of tablet (caused by swelling of disintegrant particles during absorption of water)
Binder definition
-adhesive
-to ensure granules and tablets can be formed with required mechanical strength
Glidant define
-improve flowability
-important during tablet production
-added to a granulation before tableting
Definition of lubricant
-ensure tablet formation and ejection can occur with low friction
-important during tablet production
-two mechanisms: fluid lubrication and boundary lubrication
Antiadherent definition
-reduce adhesion between the powder and the punch faces
-prevent particles from sticking to the punch
-many lubricants have also anti-adherent properties
Containers of tablets
-strips, blisters
-amber glass
-plastic with airtight
Preparation of tablets
-Direct compression (reduce time and cost, fast drug dissolution, for soluble drugs and potent drugs)
-Dry granulation (slugging, not widely used, compacting powder into large compacts)
-Wet granulation (agitation of powder by convection in presence of liquid)
Test of tablets
-Dissolution (evaluate potential effect of formulation)
-Disintegration (they pass if all particles of tablets pass through the wire mesh within 30min)
-Total hardness (force required to break tablet)
-Friability (assess ability of tablet withstand abrasion in packaging, handling, transportations)
-Content Uniformity (ensure tablet contain stated amount of medicaments)
-Uniformity in Diameter (ensure tablet are not thicker than specified size)
-weight variation
