Tablets and Suppositories

TABLETS AND SUPPOSITORIES

Dr. Basavaraj K. Nanjwade M. Pharm., Ph. D

Department of PharmaceuticsFaculty of Pharmacy

Omer Al-Mukhtar UniversityTobruk, Libya.

E-mail: [email protected]

2014/06/17 1Faculty of Pharmacy, Omer Al-Mukhtar University, Tobrum, Libya.

CONTENTSTablets

• Introduction (properties of tablet granulation)• Tablet additives and components• Disintegrant• Colorant• Flavor and sweeteners• Preparation of components for compression• Forms of compressed tablets• Processing problems• Evaluation of tablets• Tablet coating (sugar coat, film coat)


Introduction (Properties of Tablet Granulation)

• Granulation is the process in which primary powder particles are made to adhere to form larger multi-particle entities called granules.

• Granulation normally commences after initial dry mixing of the necessary powdered ingredients so that a uniform distribution of each ingredient through the mix is achieved.

• After granulation, the granules will either be packed (when used as a dosage form) or they may be mixed with other excipients prior to tablet compaction.


Tablet additives and components

• A study of the physical properties of drug molecules is a prerequisite for product formulation and leads to a better understanding of the relationship between a drug’s molecular and physicochemcial properties and its structure and action.

• These properties come from the molecular bonding order of the atoms in the molecule and may be though of as either additive or constitutive (dependent on the structural arrangement of the atoms within the molecule).


Disintegrant• The substance which are added in the tablet formulation to

ensure disintegration of the tablets into smaller particles when swallowed are called Disintegrant or Disintegrating Agents.

• These are added into the formulation of oral tablets or sublingual tablets.

• When the medicament is insoluble in water a disintegrating agent is needed.

• Disintegrating agents act in three ways:1. By swelling e.g. potato starch, maize starch, wheat starch.2. By producing effervescence e.g. sodium bicarbonate3. They melt at body temperature e.g. cocabutter


Colorant• Colours of aproved certified F. D. and C, dyes are

used. • The colours are used to improve the elegance of the

tablet. • The colours are added to the solution of the

granulating agent or these are mixed with other ingredients before granulation.


Flavours• Flavours are included in lozenges, effervescent

tablets and chewable tablets. • Flavours are volatile oils and hence they are added

into the granules just before compression of tablets. • Flavouring agent is dissolved in organic solvent and

the solution is sprayed on the granules.


Sweeteners• Sweeteners are agents are used to improve the taste of

tablets. • These are used in lozenges and chewable tablets. • Artificial sweetening agents like saccharin and

cyclamates, are not used nowadays. • Sucrose, lactose and mannitol are some of the

commonly used sweetening agents.

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1. Weighing of the ingredients2. Mixing the powdered ingredients and excipients3. Converting the mixed ingredients into granules4. Diluents5. Granulating agents6. Binding agents7. Disintegrating agents8. Lubricants9. Adsorbents10. Colouring agents, Flavouring agents and Sweetening agents.


Preparation of components for compression

Forms of compressed tablets

• Tablets are prepared by the compression method and are hence called the “Compressed Tablets”

1. Multilayered tablets2. Sustained action tablets3. Enteric coated tablets4. Sugar coated tablets5. Film coated tablets6. Chewable tablets7. Buccal tablets Sublingual tablets8. Lozenge tablets and traches9. Dental cones


Processing problems• The following defects may occur during the

compression of granules into tablets.1. Capping2. Picking and sticking3. Mottling4. Weight variation5. Hardness variation6. Double impression


• The following test should be carried to maintain the quality control of tablets:

1. Shape of tablets2. Appearance3. Content of active ingredient in tablets4. Uniformity of weight5. Disintegration test for tablets6. Dissolution test for tablets7. Mechanical strength8. Friability test.

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Evaluation of tablets

Tablet coating (Sugar coat)

• Sugar coating is done by the pan coating method. • It is one of the oldest arts to mask the unpleasant flavours

and tastes of medicaments, but nowadays sugar coating of tablets is done for improving its aesthetic value.

• The various stages in the sugar coating process are:1. Sieving2. Sealing3. Subcoating4. Syrup coating5. Finishing6. Polishing



Tablet coating (Sugar coat)

• In this case the tablets are coated by a single or mixture of film forming polymers, such as, hydroxypropyl methylcellulose, hydroxyethyl methyl cellulose, carbowax, polyethylen glycol 400 etc.

• The polymer is dissolved in some volatile organic solvent and is sprayed over the tablets in a rotating pan.

• The process is continued till a uniform good film is formed over the tablets.

• Film coating is also used to make the tablets water proof before the sugar coating.

• Film coating can be enteric or non-enteric2014/06/17 Faculty of Pharmacy, Omer Al-Mukhtar University,

Tobrum, Libya. 15

Tablet coating (Film coat)

CONTENTSSuppositories

• Introduction• Advantages rectum physiology• Drug absorption form rectum• Factors affecting formulation of suppositories• Classification of bases• Choice of adjuvant• Suppository production• Quality control• References


Introduction1. The patient have a problem with their gastrointestinal tract, is

nauseous or is postoperative. 2. Several categories of patients, i.e. the very young, the very old

or the mentally disturbed, may more easily use the rectal than the oral route.

3. The drug under consideration is less suited for oral administration.

4. The drug may be insufficiently stable at the pH of the GI tract, or susceptible to enzymatic attack in the GI tract or during the first passage of the liver after absorption.

5. The formulation into suppositories of certain drugs that are candidates for abuse, as in suicide, has also been considered.


Definition of Suppositories• Suppositories are solid dosage form of medicament for

insertion into body cavities other than mouth. They may be inserted into rectum, vagina or nasal cavity.

• The medicament is incorporated into the supository base and the product is formulated in such a way that they will either melt or dissolve in the body cavity fluid to release the medicament.

• Suppositories are available in different shapes, sizes and weights. Suppositories are used to produce local, systemic and mechanical action.


• Under normal circumstances the rectum is empty; filling provokes a defection reflex, which is under voluntary control.

• Data comparing drug absorption from freshly prepared and aged, more viscous suppositories suggest that there is enough motility to provoke the spreading even of rather viscous suppositories.

• Suppositories are inserted in to rectum to promote evacuation of the bowel.

Advantages rectum physiology


Advantages of Suppositories

1. These can be easily administered to children, old persons and to unconscious patients who cannot swallow the drug easily.

2. These are inserted into body cavity to produce local effect of the medicament incorporated in the base.

3. These are inserted into the rectum to exert a direct and rapid action on the rectum.

4. These are inserted into the rectum to promote evacuation of the bowel.

5. Suppositories are unit dosage form of drugs2014/06/17 20Faculty of Pharmacy, Omer Al-Mukhtar University,

Tobrum, Libya.

Drug absorption form rectum

• Blood supply, especially venous drainage, is important for the understanding of drug absorption.

• Recent investigation have shown that avoiding the first passage through the liver is possible, but the extent of this effect cannot be generalized, as it will depend on the actual part of the rectum through which the drug is absorbed


Factors affecting formulation of suppositories

1. Drug solubility in vehicle: The drug solubility in the vehicle is of special interest from the biopharmaceutical point of view.

2. Surface properties: The surface properties of drug particles are also important as these particles will be transferred from one phase to another.

3. Particle size: The particle size of the drug is an important parameter, both technologically and biopharmaceutically.

4. Amount of drug: A complicating factor is the amount of drug present in a suppository. If the number of particles increases, this would also increase the rate to form agglomerates.


Classification of bases• Suppository bases can be broadly classified into three

categories:-1. Fatty bases eg. Theobroma oil2. Water soluble and water miscible bases eg.

Glycero-gelatin3. Emulsifying bases eg. Witepsol, massa estarinum,

massuppol.


Choice of adjuvant

• Colloidal silicon oxide or aluminium monostearate, both approximately 1-2%

• The addition of lecithin is a worthy possibility when high amounts of solid drug are used.

• Surfactans act as wetting agents• Surfactants may also act as ‘deglomerators’ which

may prevent the formation of cake in the melting suppository, which in turn would certainly slow down the drug release.


Suppository production• Suppositories are manufactured both on a small scale

in batches of 10-20 and on a (semi) automatic scale in batches up to 20, 000 per hour.

• Essentially the mode of manufacture is similar in both cases, and involves melting of the vehicle, mixing the drug and the molten vehicle, dispensing in a former cooling to solidify and, if necessary, packing in the final container.

• This includes a number of technological processes for which the relevant theory should be considered.


Suppository production• The suppositories are prepared by any of the

following methods:-1. Rolling method2. Hot process or fusion method3. Cold compression method


1. Rolling method: It is an ancient method of preparing the suppositories. The suppository base is rolled and then desired shape is given with the hand. The method is not used nowadays.

2. Hot process or fusion method: This method is commonly used in the preparation of suppositories for dispensing purposes. The suppository base is melted, the medicament is incorporated in it and filled in lubricated mould. On cooling, suppositories are formed which are removed from the suppository mould.

3. Cold compression method: The method is useful for thermolabile and insoluble drugs because heating and stirring of the base with medicament is not required.

Suppository production


Quality control• A list of properties that should be controlled.1. Appearance (odour, colour, surface condition and shape)

2. Weight3. Disintegration4. Melting (dissolution) behaviour5. Mechanical strength6. Content of active ingredient7. Release


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Tablets and Suppositories

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