Introduction to Suppositories & Incompatibilities
Unit 4 deals with specialized solid dosage forms—Suppositories—used for delivering drugs rectally or vaginally. You will learn about selecting the right base (like Cocoa Butter) and calculating displacement values. The second half covers ‘Incompatibilities’, teaching you how to identify and correct problems when drugs or excipients react with each other in a formulation.
Syllabus & Topics
- 1Suppositories: Definition, Types, Advantages, Disadvantages
- 2Types of Bases: Fatty bases (Cocoa butter), Water-soluble bases (PEG, Glycerogelatin)
- 3Methods of Preparation: Rolling, Hot process (Fusion)
- 4Displacement Value: Calculation & Significance
- 5Evaluation of Suppositories (Melting range, Breaking test)
- 6Pharmaceutical Incompatibilities: Definition, Classification
- 7Physical, Chemical & Therapeutic Incompatibilities with examples
Learning Objectives
Frequently Asked Questions (FAQs)
Q1. What are Suppositories?
Suppositories are solid dosage forms intended for insertion into body cavities such as the rectum, vagina, or urethra, where they melt, soften, or dissolve to produce local or systemic effects.
Q2. What is Displacement Value?
Displacement value is the number of parts by weight of a medicament that displaces one part by weight of the suppository base. It is used to calculate the exact amount of base required when preparing suppositories containing insoluble drugs.
Q3. What is Cocoa Butter?
Cocoa butter (Theobroma oil) is a commonly used oleaginous suppository base. It melts just below body temperature (30–35°C), making it ideal for rectal administration.
Q4. What are Pharmaceutical Incompatibilities?
Pharmaceutical incompatibility occurs when two or more ingredients in a prescription interact and cause an undesirable physical, chemical, or therapeutic change, such as precipitation, color change, or toxicity.
Q5. Example of Physical Incompatibility?
Immiscibility of oil and water is a classic example of physical incompatibility. This problem is overcome by adding an emulsifying agent to form a stable emulsion.