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
What is the standard moisture results for hard gelatin?
13% - 16%
What is the moisture content of hypromellose capsule?
3% - 6%
True or False: Viscosity of gelatin solution increases with temperature in contrast to hypromellose solution
False: the viscosity of hypromellose solution increases with temperature in contrast to gelatin solution
Preparation of hypromellose capsules require what?
the addition of a gelling agent
How do the capsules arrange themselves in capsule filling?
by gravity
What is the machine that is involved with capsule filling?
Dosator Filling Machine
What is the dependent dosing system?
using the capsule body to measure the powder (“punching”); you have to fill to brim to have dose uniformity
What is the independent dosing system?
dosing systems whereby the powder is measured independently of the body in a special measuring device; you need enough to hit the goal weight
What prevents dehydration of capsule shell?
Edible oil (inert oils)
What are the ingredients of capsules?
- active drug
- diluent
- glidant (enhances flow properties)
- no binding agent is required
What are excipients dependent on?
- properties of the active drug
- type of filling machine to be used
- Size of the capsule shell
What are the three main requirements for powder filling?
- good flow properties (glidant)
- no adhesion
- cohesion (lactose, starch, MCC)
What are the different types of excipients?
diluents, lubricants, glidants, wetting agents, disintegrants, and stabilizers
True or False: Capsules should hydrophilic and easily dispersible
True
What influences the rates of dissolution and absorption?
particle size
What are potential problems in capsule formulation?
- weight and dose variation (causes poor powder flow)
- Demixing (mixing efficiency)
- Physical incompatibility (inappropriate selection of excipients and or drugs)
What is the purpose of a pellicle?
a barrier that restricts the release of the active drug from the capsule shell
What is a common diluent in capsule formulation and effects capsule release?
corn starch
What is the purpose of glycine and citric acid?
will help w/ increased corn starch reaction forming
What is the purpose of quality control tests?
- guarantee batch to batch quality
- meet appropriate regulatory requirements
- uniformity of filling weight
- disintergration time
- uniformity of content
What type of gel has low residual water content?
soft gel
What are the two types of soft gel dosage forms?
- chewable
- suckable
What are the pharmacopeial requirements of soft gels?
dose content
uniformity of content
weight uniformity
disintegration
dissolution
stability profile
microbial quality
