University:
Northwest College
Course:
VN 210 | Introduction to Pharmacology
Academic year:

2023
Views:

355

Pages:

2
Author:

Lauren P.

Considerations in choosing drug dosage forms The dosage form of the drug is chosen so that: 1. Can protect against damage both from outside and inside body 2. Can cover the bitter and unpleasant taste of medicinal ingredients 3. Can complement the optimum action of drugs (topical, inhalation) 4. Suitable preparations for: • unstable, insoluble drugs • diseases of various bodies 5. Can be packaged/shaped to be more attractive and enjoyable When choosing a medicinal dosage form, the following things need to be considered: Therapeutic considerations a. Patient Age • For infants and children under 5 years, oral administration is preferred for liquid rather than solid medications. • At the beginning of childhood, the drug is formulated as a tablet that is easy to chew and put in the mouth before swallowing. • Adults generally prefer convenience, prefer solid dosage forms. • For the elderly, it is usually formulated as a liquid for oral use. b. How to Give Medication • Oral: Widely used dosage forms: tablets, capsules, suspensions, emulsions, and various pharmaceutical preparation solutions. Absorption medication after oral use may occur various bodies between the oral cavity and the anus. Getting higher absorption of a drug along the food tract, its action will faster. • Rectally: The drug is often administered rectally for local effects and systemic effects are rare. • Parenteral: There are three main ways of this way which are subcutaneous, intramuscular, and intravenous. • Epicutaneous: Absorption of drugs through the skin increases if the drug is present in solution, if the drug has a good lipid/water partition coefficient, and if it is a nonelectrolyte. Biopharmaceutical Considerations Bioavailability is the percentage of the active substance in the blood compared to the dose given. Oral administration can affect the condition of the active substance. Gut flora, enzymes, food, and drink are factors that can influence chemical consistency, gastrointestinal transport rate, or absorption rate. When swallowed, orally administered drugs pass through very different anatomical and physiological environments on their way. The pH value, for example, changes from 1-3 in the stomach to 5-7 in the duodenum, and 7-8 in the ileum. The specific surface area also changes drastically from the stomach to the small intestine, where absorption occurs. Physicochemical Considerations 1. Solubility and Speed of Dissolution Dissolution is the main requirement to be able to pass through the intestinal wall in the first stage. Incomplete dissolution or metabolism in the intestinal lumen or by enzymes in the intestinal wall is the cause of poor absorption. 2. Partition coefficient between the lipoid barrier and the physiological medium of water. The oil/water partition coefficient of a drug molecule will affect absorption by passive diffusion. 3. Stability and/or speed of decomposition in physiological fluids. Drugs that will be administered orally and can degrade quickly at low pH require protection from the effects of an acidic environment stomach. 4. Ease of metabolic inactivation Metabolic inactivation of a compound after oral administration can occur in the gastric lumen, gastric mucosa, or liver.