Capsules Flashcards
What are capsules?
a drug substance is enclosed in either a hard or soft, soluble shell of a suitable form of gelatin or non-animal polymers
What are the two types of capsules?
- Hard gelatin capsules (two-piece)
- Soft elastic gelatin capsules (one-piece)
What is the most versatile and commonly used oral delivery into which drug powders, solutions or suspensions may be filled?
Gelatin capsules
What do non-animal origin capsules include?
hypromellose, polysaccharide (pullulan); polyvinyl alchohol; denatured gelatin (enteric effect) and no preservative
What are the advantages of capsules?
- accuracy of dosage*
- reasonable physical and chemical stability
- Ease of administration
- Faster onset of action than tablets (because there is no binder or compaction forces) *
- Patients acceptance
- Convenience of handling
- Mask unpleasant taste and odor (patient adherence)
What are the disadvantages of capsules?
- Not suitable for extremely soluble drugs because it could lead to toxicity
- Not suitable for highly efflorescent drugs because it releases moisture
- Not suitable for hygroscopic drugs because they absorb moisture from the environment (may cause cracking of the capsule shell)
- Large doses of low-density formulations cannot be filled into capsules
- Substances that react with gelatin should be avoided (FORMALDEHYDE)
Type A gelatin blend
obtained by acid hydrolysis of collagen from the skin and connective tissues of porcine
Type B gelatin blend
obtained by alkaline hydrolysis of collagen from the decalcified bones of bovine
What is the purpose of plasticizers?
they are responsible for the flexibility/softness
Hard gelatin capsules are used for what type of liquids?
non-aqueous (oils)
What is the size range for hard gelatin capsules?
00 - 5 (0-4 for human medicine)
What sizes of capsules are most commonly used?
0-4
What are the desirable qualities of polymers?
- nontoxic
- readily soluble in biological fluids at body temp
- quality transition properties (producing a strong flexible)
- undergoes a reversible change from solid to gel at slighly high temperatures
- excellent bloom strength and viscosity (great gel rigidity)
What does viscosity determine?
the thickness of the capsule shell
What is the difference between gelatin and hypromellose capsules?
Gelatin: soluble at high temperatures
Hypromellose: soluble at low temperatures