Capsules.ppt

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Capsules

Dr. Mohammad shariare

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Introduction

Capsules are solid dosage forms in which

medicinal agents are enclosed within hard or soft

soluble shell. The shells are generally formed

from gelatin.

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Routes of administration



Oral



Rectal



Vaginal



As unit dose container for

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Advantages of capsules

for oral

administration

1. Conveniently carried 2. Readily identified

3. Swallowing is easy for most patients, aesthetically pleasing 4. Prescribing flexibility

5. Efficiently and productively manufactured

6. Packaged and shipped at lower cost and with less breakage 7. More stable and have a longer shelf-life

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Disadvantages of capsules

 The drugs which are hygroscopic absorb water

from the capsule shell making it brittle and hence are not suitable for filling into capsules.

 The concentrated solutions which require

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Characteristics of Capsules

 Capsules are available in many different sizes and

shapes and can be used for the administration of powders, semisolids and liquids.

 _{Unpleasant tastes and odors of drugs are}

effectively masked by the practically tasteless capsule shell which dissolves or is digested in the stomach after about ten to twenty minutes.

 Capsules also can be used as a means of providing

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Capsule types



Capsule may classified

depending on nature of

shell



Hard gelatin



Soft gelatin capsules,

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Raw Materials for Capsule

1.Gelatin: main ingredient for making capsule shells.

2. FD & C and D & C colorant: to make capsules look distinctive and attractive.

3. Water - 12 to 16 % but may vary depending on the storage condition

4.Preservatives: to reduce the growth of microorganisms. sulfur dioxide

which is added as the sodium salts, bisulfite or metabisulfite, sorbic acid or the methyl propyl esters of para hydroxy-benzoic acid and the organic acids, benzoic and propanoic acids.

5.Wetting agents: To ensure that the lubricated metal moulds are uniformly

covered when dipped into the gelatin solution. E.g. of sodium lauryl sulfate.

6.Opaquants/ Opacifying agent – to make the shells opaque. E.g. titanium

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Excipients in Powder-filled

Capsule

Types of excipients used in : Powder-filled capsule

 _Diluents_{: to produce proper capsule fill volume. They can also}

improve cohesion of powders which help in transfer of powder blend into capsule shell. E.g. lactose, microcrytallince celllulose and

starch.

 _{Lubricants and Glidants}_{: Enhances flow properties. Important inin}

industrial scale preparation using high scale automated

equipment.glycol esters, silicon dioxide, stearic acid and talc.

 Disintegrants: to assist break up and distribution of capsule’s

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Gelatin

 _{Gelatin – gelatin is the major component of the capsules and has}

been the material from which they have traditionally been made.

 _{Gelatin has been the raw material of choice because of the ability of a}

solution to gel to form a solid, which enables a homogeneous film to be formed rapidly on a mould pin.

 The reason for this is that gelatin possesses the following basic

properties:

 _{It is non-toxic, widely used in foodstuffs and acceptable for use}

worldwide.

 _{It is readily soluble in biological fluids at body temperature.}

 It is good film-forming material, producing a strong flexible film  _{The gelatin films are homogeneous in structure, which gives them}

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 Gelatin is a translucent brittle solid substance,

colorless or slightly yellow, nearly tasteless and odorless, which is created by prolonged boiling of animal skin connective tissue or bones.

 Some of the disadvantages with using gelatin

for hard capsules include:

 It has a high moisture content, which is essential

because this is the plasticizer for the film

 gelatin undergoes a cross linking reaction that reduces

its solubility

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Production of Gelatin

 _{On a commercial scale, gelatin is made from}

by-products of the meat and leather industry, mainly pork skins, pork and cattle bones, or split cattle hides.

 _{Contrary to popular belief, horns and hooves are}

not commonly used.

 _{The raw materials are prepared by different curing,}

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Physical Properties of Gelatin

 _{Gelatin is a protein product produced by partial hydrolysis of}

collagen extracted from skin, bones, cartilage, ligaments, etc.

 _{The natural molecular bonds between individual collagen}

strands are broken down into a form that rearranges more easily.

 _{Gelatin melts when heated and solidifies when cooled again.}

Together with water it forms a semi-solid colloidal gel.

 _{Insoluble in cold water, soften through the absorption of up}

to ten times its weight of water; soluble in hot water and in warm gastric fluid.

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Hard Gelatin Capsule

The hard gelatin capsules:

used to manufacture most medicated agents, about 10 fold in comparison to softgels

employed in clinical trials

used in the extemporaneous compounding The empty capsule shells consist of

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Manufacturing of hard gelatin

capsule shells

The shell consists of two parts, the capsule body and the capsule cap.

The process of capsule shell production with the peg/pin method:

dipping→ drying → stripping→ trimming→ joining

The thickness of the gelatin walls must be strictly controlled.

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Dipping

 Pairs of stainless steel pins lubricated, are

dipped into the dipping solution to form caps and bodies simultaneously

 The pins are at ambient temperature, 22° C

where as the dipping solution is at 50° C in heated jacketed heating pan.

 The dipping time to cast the film is about 12

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Manufacturing of hard gelatin

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Rotation

 After dipping, the pins are withdrawn from dipping solution. They are elevated and rotated until they are facing upward.

 This helps distribution of the gelatin over the pins

uniformly and to avoid the formation of bead at the capsule ends

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Drying

 The racks of gelatin coated pins then pass into

a series of four drying ovens

 _{Drying is mainly done by dehumidification by}

passing large volumes of dry air over the pins

 Temperature elevation of few degrees are

permissible to prevent film melting

 _{Drying also must be too rapid to prevent case}

hardening

 Under drying leave film sticky for subsequent

operations

 _{Over drying must be avoided as this could}

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Stripping

 A series of bronze jaws strip the cap and body

portions of the capsules from the pins

 Trimming

 The stripped caps and bodies are delivered to

collects in which they are firmly held

 As the collects rotate the knives are brought

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Joining

 The cap and body portions are aligned

concentrically in channels, and the two portions are slowly pushed together

 The entire cycle takes about 45 minutes,

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Sorting

 The moisture content of capsules as they are

ejected from machine will be in the range of 15-18% w/w

 During sorting, the capsules passing on a

lighted moving conveyor are observed visually by inspector

 Any defective capsules spotted are thus

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Sorting

 The defects may cause serious problems

 Stoppage of a filling machine due to imperfect

cuts, dented capsules, or capsule with holes

 some defects may cause usage problems, EX.

Capsules with splits, long bodies etc.

 cosmetic faults like small bubbles, specks in

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Painting

 In general, capsules are printed prior to filling

as they are easy to handle

 Generally printing is done on offset rotary

presses having through capabilities as high as ¾ million capsules per hour

 Available equipment can print axially along

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Properties of empty capsule

 _{Empty capsules contain a significant amount of water that acts as a}

plasticizer for the gelatin film and is essential for their function.

 _{The standard moisture content specification for hard gelatin capsules}

is between 13 % w/w and 16 % w/w.

 _{This value can vary depending upon the conditions to which they are}

exposed that is at low humidity’s they will lose moisture and become brittle, and at high humidity’s they will gain moisture and soften.

 _{The moisture content can be maintained within the correct}

specification by storing them in sealed containers at an even temperature.

 _{Capsules are readily soluble in water at 37ºC.}

 _{When the temperature falls below this, their rate of solubility}

decreases. At below about 30ºC they are insoluble and simply absorb water, swell and distort.

 _{This is an important factor to take into account during disintegration}

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Capsule Filling

 Types of materials for filling into hard

gelatin capsules:

 Dry solids – powders, pellets, granules or

tablets

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Hard Gelatin Capsule

 Hard Gelatin Capsule The

hard gelatin capsule consists of two pieces in the form of cylinders closed at one end. The shorter piece is called the cap.

 This cap fits over the open

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Shape of Capsules



To prepare capsules easily differentiated

from those of other manufacturers, the

shape of the capsule end (which is

usually round) can be altered.



To ensure reliable closing of the filled

capsules, capsule shells with locking

grooves (or indentations) have been

prepared.



The two grooves fit into each other for

tight closing and prevent accidental

separation (or splitting) of the capsules.



Capsules from Capsugel are sold as

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Shape of Capsules

 Snap-Fit® has the concentric locking rings of the

body and cap which prevent reopening after filling.

 _{The Coni-Snap® capsule, which is the improved form}

of Snap-Fit®, has the rim of the capsule body which is slightly tapered. The slightly tapered body facilitates joining on high speed machines and prevents the problem of telescoping.

 Telescoping is sliding of a capsule body (or a capsule

cap) over another capsule body (or a capsule cap). The tapered rim makes it more difficult to slide a capsule body over another owing to the smaller diameter.

 _{The DBcaps® capsule is different from the}

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Figure 3.2 Drawings of an ordinary capsule (left), a Coni-Snap® capsule (center) and a DBcaps® capsule (right). In Coni-Snap® and DBcaps® capsules, the tapered rim of the body is designed to avoid telescoping, the grooves on cap and body lock together; the presence of indentations prevents

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Capsule Size

Size Volume Fill weight(g) at 0.8 g/cm3

powder density

000 1.37 1.096

00 0.95 0.760

0 0.68 0.544

1 0.50 0.400

2 0.37 0.296

3 0.30 0.240

4 0.21 0.168

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Capsule sizes

How to select capsule size?

1) The amount of fill material to be encapsulated 2) The density and compressibility of the fill

3) The final determination largely may be the result of trial.

The sizes of empty capsules

 _{For human use: 000(the largest) to size 5 (the smallest)}

 _{For veterinary use: No.s 10, 11and 12 having}

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