Dosage forms

A basic introduction to different dosage forms in pharmacy as a guide to the freshers who have started their education career in pharmacy

1. DOSAGE FORMS Ms. TENY SARA THOMAS MOUNT ZION COLLEGE OF PHARMACEUTICAL SCIENCES AND RESEARCH, ADOOR, KERALA ASSISTANT PROFESSOR B.PHARM FIRST SEMESTER PHARMACEUTICS – I (DISPENSING PHARMACY)

2. INTRODUCTION A drug may be defined as an agent, intended for use in the diagnosis, mitigation (minimize degree of loss), treatment, cure, or prevention of disease in man or in other animals. A drug is rarely administered in its pure form. They are administered in different dosage forms after converting them in to a suitable formulation. Every dosage form is combination of the drug and different kinds of non – drug components called additives. The additives are used to give a particular shape to the formulations, to increase its stability and also to increase its stability an also to increase its palatability (approvable to taste) as well as to give more elegance to the preparation.

3. Importance of Dosage Forms Many dosage forms can be easily identified from their distinct colour, shape or identifying markings. Provide safe and convenient delivery of accurate dosage. Protect drug substances from oxidation, hydrolysis, an reduction. E.g., coated tablets. Protect drugs from destructive effect of gastric juice of the stomach after oral administration. E.g. Enteric coated tablets. Conceal bitter, salty, obnoxious, taste or odour of a drug substance. E.g. capsules Provide optimum drug action through inhalation therapy. Provide for the insertion of the drug in to one of the body cavities. E.g. rectal or vaginal suppositories. Provide maximum drug action from topical administration sites. E.g. creams, ointments. Provide sustained release action through E.g. sustained tablets, sustained capsules. Provide liquid dosage form of the drugs soluble in a suitable vehicle. E.g. solutions Provide drugs within body tissues. E.g. injections Provide liquid preparations of drugs which are insoluble in different vehicles. E.g. suspensions

4. CLASSIFICATION According to Sterility According to Dose Accuracy According to Physical Form According to Route of Administration Sterile dosage forms Non - Sterile dosage forms Unit dosage forms Multidose dosage forms Solids Liquids Semi – Solids Oral External Rectal Vaginal Parenteral Ocular and Optic Nasal

5. According to Sterility Sterile Dosage Forms :- are completely free from viable microorganisms. E.g. Injections. Non – Sterile Dosage Forms :- are conventional dosage forms like tablets, capsules, liquids, ointments etc. These are free from pathogenic microorganisms. According to Dose Accuracy Unit Dosage Forms:- which contain unit amount of drug, mostly a single dose is termed as unit dosage form. Such dosage forms guarantee the administration of accurate dosage. Multidose / Bulk Dosage Forms :- include bulk powders, granules, liquids, semisolid topical preparations etc. The drug is not potent an slight variation in dose is permitted.

6. According to Physical Forms Solid Dosage Forms :- are available mostly in unit dosage forms, such as tablets, capsules, pills, cachets, powders. When drugs are to be administered orally in dry state, tablets capsules are the most convenient dosage form. They are effective and patients have no problem in their handling, identification, and administration. Some solids are packed an supplied in bulk. The bulk forms meant for internal use are supplied either as granules or fine powder. The bulk powders meant for external use are dusting powders, insufflations, snuffs, an tooth powders. Solid dosage forms Powders Granules Tablets Capsules Pills Dusting and Tooth Powders Snuffs Insufflations Effervescent Granules

7. Powders :- are solid dosage forms of medicament, which are meant for internal or external use. They are available in crystalline or amorphous form. Powders are generally used in following forms :- Bulk powders for internal use. E.g. fine powders or granules Bulk powders for external use. E.g. snuffs, dusting powders, tooth powders. Simple and compound powders for internal use. Powders in the form of compressed tablets and tablets triturates. Powders enclosed in cachets and capsules.

8. Dusting Powders :- are meant for external application to the skin and are generally applied in a very fine state of subdivision to avoid local irritation. Hence, dusting powders should be passed through a 80 sieve to enhance the effectiveness. Dusting powders are of two types :- Medical Dusting Powders – used mainly for superficial skin conditions. It should be free from dangerous pathogenic microorganisms. Surgical Dusting Powders – used in body cavities and on major wounds as result of burns and umbilical cords of infants. They must be sterilized before use. Dusting powders are mainly used for their antiseptic, astringent, absorbent, antiperspirant and antipruritic (used to relieve itching) action.

9. Insufflations :- medicated dusting powders meant for introduction into the body cavities such as nose, throat, ears, and vagina with the help of an apparatus called insufflator. It sprays the powder into a stream of finely divided particles all over the site of application. Nowadays the insufflations are available in the form of pressure aerosols, used for the administration of potent drugs. They are used to produce a local effect, as in the treatment of ear, nose and throat infections with antibiotics or to produce a systemic effect from a drug that is destroyed in the gut. Snuffs :- are finely divided solid dosage forms of medicament which are inhaled into nostrils for its antiseptic, bronchodilator and decongestion action.

10. Dentifrices (Tooth Powders) :- are applied with the help of a tooth brush for cleaning the surface of teeth. They contain a suitable detergent or soap, some abrasive substance, an a suitable flavour . Abrasive agents such as Calcium sulphate, Magnesium carbonate, Sodium carbonate are used in fine powders. A strong abrasive agent should not be used as it may damage the tooth structure.

11. Granules :- bitter, nauseous and unpleasant powders cannot be given in tablet form or in a capsule form because a large number of them are required to be taken as a single dose. These powders are not given in liquid form because of stability problem. Such medicaments are given in the form of granules. The solid medicaments are mixed with sweetening, flavouring and colouring agent. A suitable granulating agent is added to moisten the powder so as to form a coherent mass, which is then passed through suitable sieves to form granules. Then the granules are dried at temperature not exceeding 60˚C. The dried granules are supplied in single dose sachets which are dissolved in water before taking. Various antibiotics which are unstable in solution are prepared in dry granular form, packed in special type of bottles. Before taking, these granules are mixed in a specific amount of boiled and cooled water to form a homogenous solution.

12. Effervescent Granules :- are the specially prepared solid dosage form of medicament, meant for internal use. They contain a medicament mixed with citric acid, tartaric acid, and sodium bicarbonate. Sometimes, saccharin or sucrose may be added as sweetening agent. Before administration, the desired quantity is dissolved in water, the acid and bicarbonate react together producing effervescence. The carbonated water produced from the release of carbon dioxide serves to mask the bitter and saline taste of drugs. Carbon dioxide stimulates the flow of gastric juice and helps in the absorption of medicament.

13. Tablets :- are solid dosage forms of medicament which are prepared by moulding or compression. Certain additives are also added to the medicaments in the formulation of tablet Capsules :- are solid dosage forms in which one or more medicaments and inert substances are enclosed within a small shell, generally prepared from a suitable form of gelatin. They can either be hard or soft gelatin shell capsules. Pills :- are small rounded solid dosage forms containing medicament and are intended to be administered orally. Medicaments are mixed with additives to form a mass which is rolled to uniform pill pipe and then cut into a number of pills.

14. Liquid Dosage Forms Monophasic dosage forms Biphasic dosage forms Liquid dosage forms :- pharmaceutical liquid dosage forms are solutions and dispersions of drug in a suitable liquid vehicle. They are further classified as monophasic dosage forms and biphasic dosage forms. Monophasic dosage forms :- refers to liquid preparation in which there is only one phase. A true solution is clear homogenous mixture that is prepared by dissolving a solid, liquid, or gas in a liquid. Biphasic dosage forms : are liquid preparations that contain two phases, ie . the internal phase and external phase.

15. Monophasic Liquid dosage forms Internal use Biphasic Liquids Mixture Syrup Elixir Linctus Applied on Skin Liniment Lotion Applied on Skin Gargles Mouth Wash Throat Paint Instilled into Body Cavities Douches Nasal Drops & Spray Eye Drops & Lotions Douches

16. Monophasic Liquids – further classified as liquids for internal use and liquids for external use Syrups – simple syrup is a viscous, saturated solution of sucrose in purified water. The concentration of sugar is 66%w/w. The syrups containing medicated substances are called medicated syrups and those containing aromatic substances are called as flavoured syrups. Elixirs - are clear, pleasantly flavored, sweetened hydro alcoholic liquids intended for oral use. The main ingredients of elixirs are ethyl alcohol (4-40%), water, glycerin, or propylene glycol, flavouring agent, syrup and some suitable preservative. Linctuses – are viscous liquid and oral preparations that are generally prescribed for the relief of cough. They contain medicaments which have demulcent (relive inflammation), sedative, expectorant actions. Taken in small doses, sipped and swallowed slowly. Drops – are preparation s meant for oral use. These preparations contain potent medicaments (shows response at lower concentrations), hence, the dose must be measured accurately. This is achieved with the help of dropper. Mixtures – are preparations meant for oral administration which medicaments are dissolved or suspended in a suitable vehicle. Mixtures are not prepared to keep them for a long time because they are prepared for acute conditions like indigestion, diarrhoea, constipation etc.

17. Liniments – meant for application on the skin, that are usually applied to the skin with friction or rubbing of the skin. Lotions – meant for external application without friction. They are applied direct to the skin with the help of absorbent material, such as, cotton wool or gauze soaked in it. They are used for local action as cooling, soothing, or protective purposes. Gargles – are aqueous solutions to be used in the mouth to prevent or treat throat infections. Mouthwashes – are aqueous solutions with a pleasant taste and odour use to make clean and deodarise the buccal cavity. Throatpaints – are viscous liquid preparations used for mouth and throat infections. Glycerin is commonly used as a base because being viscous, it adheres to mucous membrane for a long period.

18. Douches – is a medicated solution meant for rinsing body cavities like ear, eyes, nasal or vaginal cavities. Ear drops – are solutions of drops that are instilled into the ear with a dropper. Nasal drops – are solutions of rops that are instilled into the nose with a dropper. Nasal sprays –are used to reduce nasal congestion and to treat infections. The main aim is to retain the nasal solution in the droplet form in the nasal tract. Eye drops – are sterile solutions or suspensions of drugs that are instilled into the eye with a dropper. Eye lotions – are aqueous solutions used for washing the eyes.

19. Biphasic Liquids – Emulsions – is a biphasic liquid preparation containing two immiscible liquids, one of which is dispersed as minute globules into another, with the help of an emulsifying agent. The liquid which is converted into minute globule is called the dispersed phase, and the liquid in which the globules are dispersed is called continuous phase. Suspensions – are biphasic liquid dosage form of medicament in which finely divided solid particles are dispersed in a liquid or semisolid vehicle. Biphasic Liquid Dosage Forms Internal use – Suspensions External use – Emulsions

20. Semisolid Dosage Forms :- are dermatological preparations intended to apply externally on the skin to produce local or systemic effect (effecting the entire body). Semisolid dosage forms Ointments Pessaries Creams Pastes Suppositories Topical Gels Poultices

21. Ointments – are semisolid preparations made with or without medicaments intended for external applications. Ointments spread under applied pressure and adhere to the skin. Creams – are semisolid emulsions intended for application on the skin with better spreading ability. Creams are mainly of two types :- oil based creams and aqueous creams. Pastes – are basically ointments containing high percentage of insoluble solids. When packed they should be soft enough to extrude from the tube and firm enough to retain their form when extruded. Topical Gels – are transparent or translucent non – greasy, semisolid preparations meant for external application to the skin or mucous membrane.

22. Poultices – are viscous pasty preparations applied hot to the skin to treat an aching, inflamed, or painful part of the body. Suppositories – are stiffened semisolid dosage form for inserting into body cavities like rectum, vagina or urethral tract. They melt at body temperature or soften, disintegrate or dissolve in the fluid of the body cavity after being inserted. Pessaries – are meant for introduction in to the vagina. They are larger than suppositories and may be conical, wedge shaped or rod shaped.