Introduction to Pharmaceutical Dosage Forms – PST04104 Pharmaceutical Dosage Forms
NTA Level 4 • Semester 1 • PST04104 Introduction to Pharmaceutical Dosage Forms Pharmaceutical Dosage Forms • Source Session/Topic 1 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 1: Introduction to Pharmaceutical Dosage Forms Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define Dosage Form • Classify Pharmaceutical Dosage Forms According to their Physical Forms and Routes of Administration • Explain the Importance of Dosage Forms Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board, chalk and whiteboard markers • Overhead projector • Computer SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction of Learning Tasks | |2 |10 minutes |Presentation |Definition of Dosage Forms | | | |Brainstorming | | |3 | |Presentation |Classification of Dosage Forms | | |75 minutes |Small Group | | | | |Discussion | | |4 |20 minutes |Presentation |Importance of Dosage Forms | | | |Buzzing | | |5 |05 minutes |Presentation |Key Points | | 6 |05 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Definition of Dosage Forms (10 minutes) | Activity: Brainstorming (5 minutes) | |ASK students to brainstorm on the following question | |What is dosage form? | |ALLOW few students to respond | |WRITE their responses on the flip chart or board | |CLARIFY and SUMMARIZE their responses using the contents below. | • Dosage forms: o These are the means by which drug molecules are delivered to the sites of action in the body o They are the drug delivery systems o Example of pharmaceutical dosage forms are tablets, capsules, syrups, suspensions, injections, creams and ointments o Selection of right dosage forms depends on the situation of a patient (emergency or unconscious) and the location of the disorder STEP 3: Classification of Dosage Forms (75 minutes) |Activity: Small Group Discussion ( 30 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | |What are the classes of Pharmaceutical dosage forms? | | | |ALLOW students to discuss for 15 minutes | | | |ALLOW few groups to present and the rest to add points not mentioned | | | |CLARIFY and SUMMARIZE by using the contents below | • Dosage forms are classified according to Physical forms and Route of administration • Classification according to physical forms o Solid dosage forms ▪ The solid dosage forms are mainly of two types, tablets and capsules. Others are powders, pills and cachets ▪ Tablet is a compressed solid dosage form (of uniform volume of particles) containing medicaments with or without excipients ▪ Capsules are solid preparations with hard or soft containers “shells”, (commonly but not exclusively of gelatine) of various shapes and capacities, usually containing a single dose of active ingredient(s) ▪ he solid dosage forms are advantageous as they ensure the means for accurate dosing, portable (lighter) and easy handling , cheap for large scale production, easy to control quality and masking unpleasant tastes o Semisolid dosage forms ▪ Semisolid preparations comprise a number of products, which when applied to the skin or accessible mucous membranes tend to alleviate or treat a pathological condition or offer protection against a harmful environment ▪ They are intended for local drug delivery on the skin, cornea, rectal tissue, nasal mucosa, vagina and others ▪ Most of them are non-irritating ▪ Examples are ointments, creams, gels, pastes and poultices o Liquid dosage forms ▪ Liquid dosage forms are homogeneous or heterogeneous preparations containing one or more active ingredients in a suitable vehicle ▪ The liquid dosage forms are advantageous as they are more readily available for absorption, easily swallowed than tablets or capsules and therefore suitable for children and elderly patients ▪ The gastric irritation caused by certain drugs when they are administered as a solid dosage form may be reduced or avoided when liquid dosage forms are used ▪ The disadvantages of liquid dosage forms include; less stability in liquid formulation, susceptibility to microbial contamination, difficultness in masking unpleasant taste and inconvenience to store and transport due to bulkiness ▪ Also administration of the correct dose is less precise since in involves the use of 5ml spoon, an oral syringe or volumetric dropper and the dispersion systems have to be shaken before use to allow accurate dosage ▪ Examples of liquid dosage forms are solutions, suspensions, spirits, tinctures, mixtures and others. o Gaseous dosage forms ▪ The small drug particles are usually compressed with air ▪ These forms include aerosols and inhalers • Classification according to Route of Administration o Oral dosage forms ▪ Are usually intended for systemic effects resulting from drug absorption through the various mucosa of the gastrointestinal tract ▪ It is the simplest, most convenient and safest means of drug administration ▪ The onset of action depends on the rate of absorption ▪ The disadvantages include relatively slow onset of action, possibilities of irregular absorption and destruction of certain drugs by enzymes or secretions of the gastrointestinal tract ▪ The most popular oral dosage forms are tablets, capsules, suspensions, solutions and emulsions o Parenteral dosage forms ▪ These are medicines which injected via a hollow needle in to the body at various sites. ▪ The main parenteral routes are subcutaneous (S.C), intramuscular (I.M) and intravenous (I.V) and the less frequently used intrathecal ▪ The parenteral route is preferred when rapid absorption is essential, as in emergency situations or when patients are unconscious or unable to tolerate oral dosage forms ▪ Absorption after parenteral drug delivery is rapid ▪ Injectable preparations are usually sterile suspensions or