Drug dosing forms

Completed forms of the pharmaceutical preparation in which prescribed doses of medication are included. They are designed to resist action by gastric fluids, prevent vomiting and nausea, reduce the undesirable taste and smells associated with oral administration, achieve a high concentration of drug at target site, or produce a delayed or long-acting drug effect

Purpose for different dosing forms 1-Accurate dose. 3- Protection from gastric juice e.x. coated tablets. 4- Masking taste and odour. 5- Placement of drugs within body tissues. 6- Sustained release medication. 7- Optimal drug action. 8- Use of desired vehicle for insoluble drugs.

factors to be considered while determining drug dosage form 1) Physical appearance of the drug product 2) The way the product is administered 3) Frequency of dosing, 4)How pharmacists and other health professionals might recognize and handle the product.

types of dosage forms Solid dosage forms E.X: Capsules, Tablets , Powder, Lozenge Semisolid E.X Cream, gel . ointment Liquid dosage forms . E.X Solution , Suspension, Lotion Gaseous dosage forms E.X , Aerosole, Inhalents, Gas.

Solid dosage forms 1- Capsules: Consisting of a shell and a filling. either a hard or soft soluble container of suitable form. The shell is composed of two halves that fit together and which are sometimes sealed with a band. They are intended to mask the smell and taste of the drug substance.. made from gelatin, starch, or cellulose, or other suitable materials, and are filled with solid or liquid ingredients Capsules are tasteless, easily administered

types of capsule Hard gelatin capsules A. Coated capsules Soft elastic capsules

Coated capsules

Types of coated capsules 1- extended release capsule The capsule is covered in a designated coating, and which releases a drug in such a manner to allow at least a reduction in dosing frequency as compared to that drug presented as a conventional dosage form. E.X (ferofolic® )

Extended release capsule

2- delayed released capsule A solid dosage form in which the drug is enclosed within either a hard or soft soluble container made from a suitable form of gelatin, and which releases a drug (or drugs) at a time other than promptly after administration.EX: Enteric-coated articles are delayed release dosage forms. E.X Manoprolol (Propranolol)

A- Enteric-coated capsules. Remain intact in the stomach, but dissolve, and release the contents of the capsule once it reaches the small intestine. They delay the release of drugs which are inactivated by the stomach contents or may irritate the gastric mucosa. Enteric coatings are prepared of synthetic polymers

B- film coated capsule The capsule is covered in a designated film coating , and which releases a drug (or drugs) in such a manner to allow at least a reduction in dosing frequency as compared to that drug (or drugs) presented as a conventional dosage form.

4- gelatine A solid dosage form in which the drug is enclosed within either a hard or soft soluble container made from a suitable form of gelatin; through a banding process, the capsule is coated with additional layers of gelatin so as to form a complete seal

B- Liquid filled capsule In which the drug is enclosed within a soluble, gelatin shell which is plasticized by the addition of a polyol, such as sorbitol , and is therefore of a somewhat thicker consistency than that of a hard shell capsule; typically, the active ingredients are dissolved or suspended in a liquid vehicle.

Liquid filled capsule

Tablets are solid dosage forms containing drug substance with or without suitable diluents, and prepared by compression. This is the most frequently used dosage form of administering a drug. They are swallowed, chewed. Scoring of some tablets into halves or quadrants facilitates breaking them if a smaller dose is needed. A tablet’s color or shape can help identify it. Advantages: simplicity and economy, stability and convenience in packaging, accuracy of dosage, portability, and ease of administration.

suitable diluents usually in powder form, pressed or compacted into a solid. The excipients(an inactive substance that serves as the vehicle or medium for a drug or other active substance). include, lubricants to ensure efficient tableting; designated to ensure that the tablet breaks up in the digestive tract; sweeteners or flavours to mask the taste of bad tasting active ingredients; and pigments to make uncoated tablets visually attractive.

Types of tables 1- Chewable tablet? A solid dosage are large, hard tablets, difficult to swallow, intended to be crushed before ingesting producing a pleasant tasting residue in the oral cavity that is easily swallowed and does not leave a bitter or unpleasant after-taste. . E.X :antacid tablet

2- delayed release tablet A solid dosage form which releases a drug (or drugs) at a time other than promptly after administration. Enteric-coated articles are delayed release dosage forms. ex Diclofenac

3- coated tablet Are coated with substances that resist solution in gastric fluid but disintegrate in the alkaline contents of the intestine. Enteric coating is used for drugs with a gastric irritant action, for drugs which are unstable in the acid medium of the gastric contents or if the drug should act on the intestine. (e.g., Voltaren, Salazopyrin).

4- sugar coated tablet are smooth, oval compressed tablets containing sugar coatings. Sugarcoating provides both protection and sweet taste but the coating operations take a long time. Example: Nifedipin, , ferrous gluconate

5-film coated tablet are compressed tablets which are covered with a thin layer or a film of polymeric substances to protect their contents from moisture or to mask the taste of the ingredients. rantidine)

6- extended release tablet Are formulated to release the drug slowly over a prolonged period of time. These dosage forms have been referred to as prolonged-release (PR) or sustained-release (SR) dosage forms as well. ex tapentadol

7- effervescent tablet contain sodium bicarbonate and an organic acid in addition to the drug substance. In the presence of water, these additives react liberating carbon dioxide which acts as disintegrator and produces effervescence. These tablets are soluble and they are taken readily and absorbed rapidly (e.g., Vit C, Supradin, etc.)

powder and granules is a mixture of finely divided drugs and/or chemicals in a dry form that may be intended for internal (oral powders) or external (topical or dusting powder) use. 1-Powders used in a dry form 2- Powders to be dissolved in water before use 3- Powders for reconstitution

Powders used in a dry form A-Powders for topical application e.g. antibacterial and antifungal powders, or non-medicated powders e.g. Talc powder (protective action).

2- Powders to be dissolved in water before use A- Antacids and laxatives (large dose) are used by mixing the directed amount of powder (usually one teaspoonful) in a portion of water before swallowing.

Powders for reconstitution A- Oral antibiotic; the antibiotic is prepared in a dry form (powder or granules) and packed in a sealed bottle, a given amount of water is added before use. Once it is reconstituted the patient should be warned of the short shelf life (usually 1-2 weeks).

B- Powders for injection; They may be classified as bulk or divided powders. Injections of drugs that are unstable in solution must be made immediately prior to use and are presented as sterile powders in ampoules. Sterile water for injection is added from a second ampoule and the injection is used immediately.

Granules Granules are prepared aggregates of powdered materials to form a larger particle (2-4 mm). Granules may be used as such (granules of medicinal value) or in making tablets and capsules.

types of granules Granule delayed release Granule effervescent

lozenge A solid preparation containing one or more medicaments, usually in a flavored, sweetened base which is intended to dissolve or disintegrate slowly in the mouth. E.X Dextromethorphan

Suppository A solid body of various weights and shapes, adapted for introduction into the rectal of the human body; they usually, soften, or dissolve at body temperature. Eg: Suppository( Hydrocortisone).

Liquid dosage forms

Liquid dosage forms Solutions Suspensions Colloids Emulsions Monophasic liquid D.F Solutions Polyphasic liquid D.F Suspensions Colloids Aqueous solutions Non-aqueous solutions Emulsions

Solution: Are homogeneous mixtures that are prepared by dissolving a solid, liquid, or gas in another liquid. The molecules of the dissolved substance are dispersed among those of the solvent. Many pharmaceuticals are simply solutions of a medicament in water, alcohol, ether, glycerin, oils, chloroform ) . Solutions are intended for internal, external, and parenteral administration.. Eg (Metronidazole,Povidone & Iodine )

Classification of solutions (i) According to the route of administration - Oral solutions through oral route Otic solutions instilled in the ears Ophthalmic solutions instilled in the eyes Topical solutions applied over skin surface

Aqueous solutions include those pharmaceutical forms that are prepared with purified water or aromatic water as a solvent. Simple solutions for oral administration EX, douches, enemas, gargles, mouthwashes, nasal and otic solutions.

Nonaqueous solutions : Are the alcoholic and hydroalcoholic solutions, ethereal solutions, glycerin solutions, etc. Solutions may be prepared in bulk or as single-use packages, and they are usually bottled automatically .

Suspension Are two-phase systems consisting of a finely divided solids dispersed in liquids. If the drug is insoluble or poorly soluble, a suspension may be the most suitable dosage form. The taste of drugs can be improved if they are supplied in suspension form rather than solutions EX:(Albendazole) may be formulated for1- oral, 2- parenteral (intramuscular or intrarticular) 3-topical administration.

The main ingredients in a suspension are: A drug Natural viscosity agents (natural gums and cellulose derivatives) An external medium – it is usually water for oral preparations; or other polar liquids (glycerin, alcohol)

Emulsions (liquid in liquid dispersion): emulsions are two phase system in which one liquid is dispersed throughout another liquid in the form of small particles.

Syrup: An oral solution containing high concentrations of sucrose or other sugars; the term has also been used to include any other liquid dosage form prepared in a sweet and viscid vehicle, including oral suspensions. Eg : (selvodine )

Elixir. A clear, pleasantly flavored, sweetened hydroalcoholic liquid containing dissolved medicinal agents; it is intended for oral use. Eg: (Fungal infection)

Tincture An alcoholic or hydroalcoholic solution prepared from vegetable materials or from chemical substances. Eg : Iodine tincture

lotion An emulsion, liquid dosage form. This dosage form is generally for external application to the skin. EX: lotion (Calamine ).

Spray A liquid minutely divided as by a jet of air or steam Eg : spray (Lidocaine)  

types of spray 1.Spray metered- 2.Spray suspension

gaseous dosage form 1- Aerosole 2- Inhalents 3. Gas 1- aerosole Are heterogeneous systems consisting of very finely subdivided liquid or solid particles (optimum size 0,5–3 μm) dispersed in a gas medium. They can be inhaled (nasally or orally) or applied topically for treatment of systemic and topical diseases. types of aerosols

inhalent A special class of inhalations consisting of a drug or combination of drugs, that by virtue of their high vapor pressure can be carried by an air current into the nasal passage where they exert their effect. Advantages: rapid onset of action; bypass the hepatic circulation; avoidance of degradation in the gastrointestinal tract; lower dosage that minimizes adverse reactions; simple, convenient and acceptable therapy.

1- Cream 2- Gel 3- Ointment 4-Paste 5- Jelly. semisolid dosage form A semisolid dosage form is not pourable; it does not flow or conform to its container at room temperature. It does not flow at low shear stress and generally exhibits plastic flow behavior. semisolid drug dosage forms 1- Cream 2- Gel 3- Ointment 4-Paste 5- Jelly.

1- Cream An emulsion, semisolid dosage form, usually containing > 20% water and volatiles 5 and/or < 50% hydrocarbons, waxes, or polyols as the vehicle. This dosage form is generally for external application to the skin or mucous membranes. Eg (Lidocaine)

Ointment. A semisolid dosage form, usually containing <20% water and volatiles and >50% hydrocarbons, waxes, or polyols as the vehicle. This dosage form is generally for external application to the skin or mucous membranes Eg ( Glyceryl trinitrate)

Gel A semisolid dosage form that contains a gelling agent to provide stiffness to a solution. A gel may contain suspended particles. Eg –activated dimethicone).  

parenteral drug dosage form Dosage forms of drugs that can be applied through parenteral route only . Eg : Injection. Act more rapidly and reliably ,thus more useful for emergency situations . they require suitable equipment . there are two types of injectable preparation

Ampule which contains sterile drug solution and used once they opened An ampule typically indicates a sealed glass container that holds some pharmaceutical compound. Its opening requires breaking the neck of the bottle.

Vial It includes any small container that holds pharmaceutical or chemical compounds. Typically made of glass, the vial can be sealed or not sealed. The vessel closes with a screw on cap, or a rubber. Sometimes, its top includes a dropper to measure the liquid to retrieve. which is designed to contain one or more multiple doses having a rubber cover to avoid contamination