Lecture 5 Flashcards
What are solutions in pharmaceuticals?
Solutions are homogeneous mixtures of two or more components, with the solvent being the component in the largest proportion and the solute being dissolved in the solvent.
What are the advantages and disadvantages of solutions as oral dosage forms?
Ease of administration, better absorption, a more pleasant experience, and reduced irritation.
Disadvantages include poorer stability, challenges in taste masking, less accurate dosing
What factors should be considered when formulating oral solutions?
Solubility and choice of solvent, pH and buffers, preservatives
What is the importance of solubility for API absorption?
APIs must be in solution to be absorbed. They cross the gastrointestinal tract via passive diffusion and active transport, influenced by factors like lipid solubility and molecular weight
How do lipophilic and hydrophilic forms of APIs differ in absorption?
The un-ionized form is typically lipophilic and diffuses easily across cell membranes, while the ionized form is hydrophilic and has more difficulty.
How does pH and pKa influence API ionization?
The proportion of ionized and un-ionized forms is determined by environmental pH and the API’s pKa
What are suspensions in pharmaceuticals?
Suspensions are heterogeneous mixtures of insoluble solid particles dispersed in a liquid medium.
What are the two types of suspensions?
Flocculated suspensions form an open network that settles rapidly but is easily redispersed, while deflocculated suspensions have individual particles that settle slowly and may cake.
What are the advantages and disadvantages of suspensions?
Advantages: They offer effective absorption, delayed drug absorption for prolonged action, superior API stability
Disadvantages: particle size changes, sedimentation, caking difficulties
What are parenteral liquids, and what sterilization methods are used?
Parenteral liquids are for injection or infusion and require sterile production. Sterilization methods include radiation, autoclaving, and ethylene oxide.
What is the difference between lyophilized and liquid parenterals?
Lyophilized forms offer increased stability and ease of transport, while liquid forms provide immediate use and are preferred for APIs stable in liquid form.
What vehicles are used in parenteral formulations?
Aqueous vehicles (Water for Injection) are common, and non-aqueous vehicles may be needed for stability or solubility, though toxicity must be assessed.
What excipients are used in parenteral formulations?
Antioxidants, inert gases, chelating agents, solubilizing agents, antimicrobial agents, buffers, tonicity adjustment agents, and protectants.
