1- Drug forms.pdf

Dosage forms and preparations (Formulations) Prof. Abd El-Aty Pharmacology Department Medical Faculty Ataturk University  Formulations Formulation should ensure that – A pharmacologically active drug can be synthesized – A medication...

Dosage forms and preparations (Formulations) Prof. Abd El-Aty Pharmacology Department Medical Faculty Ataturk University  Formulations Formulation should ensure that – A pharmacologically active drug can be synthesized – A medication (medicine) can be produced, administered, and delivered in a desired amount – Via the appropriate route of administration – Where it reaches its physiological and pharmacological site of action – Within the optimal time – With the desired therapeutic effect – While minimizing undesired adverse effects Cont’d  Dosage form A pharmaceutical drug (medication or medicine) is a substance that is used to treat cure, prevent, or diagnose a disease Dosage forms are simply classified as solids, liquids, and semisolids Each form of drug has certain benefits (advantages) in terms of its effectiveness, ease of use, and safety in addition to disadvantages  Issues that need to be addressed when considering different forms Protect the active compound from exposure to the atmosphere, to ensure a long shelf-life Protect the active ingredient from gastric acidity or other enzymes Mask any bitter taste – The taste of the active ingredients (AI) is often strongly bitter or excessively sour or salty To extend the drug reaction time through controlled release action Drug stability (Shelf-life) Drug stability is the ability of the various dosage forms to maintain the desirable physical, chemical, therapeutic, and microbial properties during the time of storage and usage by the patient  Pharmaceutical Excipients Excipients are the constituents of the pharmaceutical form other than the AIs It includes, coloring, preservatives, adjuvants, stabilizers, thickeners, emulsifiers, flavouring, and aromatic substances  Different agents that may be used to make oral drugs palatable Vehicles – Used to suspend or dissolve the drug and even to mask its taste Coloring agent – Make the drug visually appealing to the patient Sweetener – Added to liquid forms of medicine to make them palatable Flavorings – Agents added to mask the taste Cont’d Cont’d  Scored tablets Indented line (groove) running across the top Can easily be broken into two pieces with a knife (fingers) to produce two doses  Enteric-coated tablets Covered with a special coating (polymers) that resists gastric acidity (maintaining the stability) and minimizing the side effects but dissolves in the alkaline media (small intestine)  Cont’d Sugar coated tablets Film (skin like) coated tables Film (skin like) coated tables  Cont’d Film/sugar-coated tablets contain a thin layer of coating that dissolves in the stomach, whereas enteric-coated tablets have a unique coating that resists stomach acid and dissolves in the small intestine.  Slowly-release tablets Provide a continuous, sustained release of a certain drug Abbreviated as SR (slow-release or sustained-release), LA (long-acting), ER (extended-release), or CR (controlled-release)  Caplets Coated tablets in the shape of a capsule Easier to swallow  Cont’d Effervescent tablets Chewable tablets  Lozenges- tablets Formed with a harden base of sugar, water, and flavorings Never swallow Dissolve slowly in mouth  Cont’d Buccal tablets Sublingual tablets  Capsules Comes in two varieties Soft gelatin- capsule – Manufactured in one piece in which the drug is in a liquid form inside the soft shell Hard shell- capsule – Manufactured in two pieces that fit together and hold the drug which is in a powder or granular form Generally easier to swallow  Powder Finely ground form of an active drug Can be incorporated in a capsule Glass vials - reconstituted with sterile water Packaged - reconstituted with water For external and internal use  Pellet/Bead Drug can be implanted in the body in the form of a pellet or bead that slowly releases into tissue Cont’d Crushing tablets or opening capsules: many uncertainties, some established dangers It might alter the drug's absorption, resulting in either overdose (fatal) or under dosing (treatment ineffective) In SR: the AI is no longer released and absorbed gradually, resulting in overdose The AI released may degrade on contact with light, moisture or the food with which it is mixed Exposure to drug particles could be carcinogenic, teratogenic or fetotoxic Hydrophilic Differences between ointment, cream, gel, and paste Cont’d Classification of liquid  Liquids Oral liquids are formulated as solutions, suspensions and emulsions depending on the nature of the AIs particularly solubility and stability Solution not need to be mixed Solutions are fully dissolved  Types of solutions Mixtures – Simple liquid preparations containing dissolved medicaments (such as Rehydran soln) Elixirs-alcohol (3-25%) and water base with added sugar and flavoring Syrups-sugar (sucrose), water and flavoring thicker Linctuses – viscous liquid – used as demulcent (soothing) effect Tinctures- inorganic compounds dissolved in alcohol and water base - used topically  Cont’d Spirits (essences) – Organic compounds (volatile or essential oil) dissolved in Alcohol Sprays – Solutions that are delivered as a mist against the m.m. of the nose and throat Injectable Solutions – Sterile solutions, suspensions or emulsions designed for parenteral administration Gargles and Mouthwashes Enemas, Douches and Irrigation Solutions  Suspension types Heterogeneous mixture in which the solute particles do not dissolve, but get suspended throughout the bulk of the solvent Is there any difference between suspension and emulsion? Always “shake well before use” Largely, are intended for oral use Some may be administered by other routes, such as the rectal, otic and ophthalmic It can be administered via IM route  Solutions vs suspensions Solutions Suspension Solutions are homogeneous mixtures Suspensions are heterogeneous mixtures The size of particles in solutions are very small Suspensions have large sized particles Solutions are transparent when exposed to light Light cannot pass through the suspensions Solute takes the properties of solvent in solutions Solute has its own distinct properties in suspensions The components of solutions cannot be separated by The solute can be separated from solvent by filtration filtration NaCl in water, sugar in water, sublimes in air are Oil in water, dust in air are examples of suspensions examples of solutions Emulsion vs. suspension  Lotions Low-viscosity topical preparation intended for application to the skin (without friction) What are the difference between lotion, gel and cream? Gel-suspended in a thicken water medium- does not have to be shaken They cool, soothe, or protect the skin Liniments vs. lotions  Liquid sprays Water and alcohol base Pump or aerosol spray Some dispensed as foams  Transdermal patch Consist of a multi- layered disk of a drug reservoir, a porous membrane, and a adhesive layer placed on the skin