March 23 - Capsules Flashcards
What is the most common dose form for adults? Why?
Oral solids, tablets and capsules are the most common dose form for adults. They are convenient to take and carry, they are readily identified and attractive in appearance, they are efficient to fabricate, package and ship, and solids tend to be more stable than other dose forms
What are capsules? What are they made of? How are capsules taken and why is this important?
Capsules are solid dose forms where the medicinal and excipient materials are enclosed in a shell of gelatin. May be hard or soft depending on composition. Pharmacists often use empty hard gelatin shells for extemporaneous compounding of oral solids. Generally capsules are meant to be taken intact but occasions may arise when contents are mixed with food or liquid. Opening may be inappropriate with enteric coated, sustained or controlled release products and must ensure that the caregiver understands dose form must be given intact and not opened, crushed or otherwise altered
Describe different capsule shells. What are they composed of? Describe the moisture content of different capsules. How should capsules be stored and why is this important? Describe the size of capsules?
Shells may be hard or soft. Soft shells require very specialized equipment. Hard shells well-suited to extemporaneous compounding. Composed of gelatin and water. Soft shell contains a plasticzier which may be a sugar or glycreol and more water (approx 30%). Hard shells may be coloured with dyes and/or made opaque with excipients like titanium dioxide. Contain about 15% moisture: if reduced they become brittle and if increased they become sticky. Subject to microbial growth so storage away from excessive moisture or dryness. Capsule shell comes in two parts - the body and the cap. There are a variety of sizes from small (5) to large (000). Weight of material filing shell dependant on bulk density which is a function of particle size
Describe the importance of characterizing the powders that fill the capsules. Why is bulk density important? Why is particle size important?
The bulk density of a powder expresses the weight of a powder in a specified volume. Powders are composed of particles and voids so the volume occupied by a given number of particles depends on how closely they are packed. Packing of particles depends on their shape, cohesiveness, short-range motion and external forces. Bulk density of a powder tends to increase with tapping or vibration which causes the particles to move and allow smaller particles to occupy the voids between larger particles.
How is tapped density determined?
USP has two methods for tapped density determination: 100 g of material is placed in a graduated cylinder and is tapped in increments of 1250 times until no further decrease in volume is seen. For method I the drop is 14 mm and for method II 3 mm
What are the three steps in preparing capsules
Developing formulation and selection of capsule size
Filling the shells
Cleaning and polishing the shells
Describe the step: development of formulation and selection of capsule size.
Diluent of filler may be needed. Lactose is commone but may use microcrystalline cellulose (MCC) or starch and occaisionally a disintegrant like pre-gelatinized starch. On industrial level, may need lubricant of glidant like magnesium stearate or silicon dioxide. Particle size of all powders should be similar to ensure homogeneity. Capsule size will depend on bulk density and quantity of powder but calibration will be needed
Describe the filling of the shells
Body filled and not the cap. For extemporaneous preparation may be done manually using punch method or with filling machine. For the punch method fill is prepared using trituration and geometric dilution; excess is always prepared. Fill spread out in layer and capsule body is punched into fill repeatedly using vertical motion until full. Cap loosely replaced and net weight checked, adjusted in necessary and cap locked on. For machine do not need excess and weights checked after capsules closed. Hands washed and gloves worn when filling capsules
Describe cleaning and polishing
Once capsules filled and caps set, wipe with clean cloth, tissue or gauze. In industry use vacuum cleaner device. Removal of external powder important for pharmaceutical elegance. Also powder often bitter and there is potential for undesirable topical exposure
How should patients be counseled on the proper use of capsules? Why is water important? What are other important pieces of information that patients should be aware of?
Solid dose forms for oral use are taken by placing the dose on the tongue and swallowing with a glass of beverage like water. Without using water or beverage dose can lodge in esophagus. Timing relative to meals may be important to bioavailability and/or efficacy. If controlled or sustained release product patient should be cautioned against breaking, chewing or crushing the capsule. Storage in dry cool place away from children or pets
What are the five steps for calculations for capsule filling
Select shell size
Fill separate shells with each drug and excipient and determine and record net weight
Calculate the diluent displacement weight for each drug
Calculate the amount of diluent required for each capsule
Calculate the total quantities of drug and diluent required for the number of prescribed capsules
