Liquid Dosage Forms Overview

What percentage of sucrose is contained in Syrup BP?

List one advantage of liquid dosage forms.

What is one disadvantage of liquid dosage forms?

Why is water the most widely used solvent in pharmaceutical preparations?

What type of water is used for parenteral solutions?

Explain one reason why liquid dosage forms allow for immediate drug absorption.

What is necessary for a type of pharmaceutical water to be considered 'pyrogen-free'?

Which method is commonly used to prepare purified water in pharmaceutical settings?

What type of pharmaceutical water is specifically required to be CO2-free?

Name one characteristic that disadvantages liquid dosage forms regarding dosage administration.

Liquid Dosage Forms

Solutions: Solvent is typically present in greater amount.
Exceptions: Syrup BP has 66.7% w/w sucrose (solute) in 33.3% w/w water (solvent).

Advantages of Liquid Dosage Forms

Easier to swallow (especially for children and the elderly).
Drugs are immediately available for absorption (even if finely divided or acidic).
Uniform distribution of drug (like in suspensions or emulsions).
Irritable drugs (like aspirin or potassium chloride) are better absorbed as solutions, leading to less gastric irritation.

Disadvantages of Liquid Dosage Forms

Liquid dosage forms can be bulky, taking up more space for transport and storage.
Containers may be damaged to the point of needing replacement
Stability of drug and excipients might be affected.
These forms are conducive to microbial growth.
Dosage administration can sometimes be inaccurate.
Drug taste can be an issue.

Choice of Solvent - Aqueous Solutions

Water is the most common solvent due to physiological compatibility and lack of toxicity.
Water has a high dielectric constant, which aids in dissolving ionic materials.
Water does not have a high degree of selectivity.

Types of Pharmaceutical Water

Purified Water BP: Freshly boiled and immediately cooled before use, no salts. Distillation or deionization is employed for purification.
Water for Injection: Used in parenteral solutions. It must be sterile, pyrogen-free, and salt-free.
Special types of Water for Injection include CO2-free (e.g., phenobarbital sodium, aminophylline) and O2-free (e.g., apomorphine, ergotamine maleate). Apyrogenic distilled water is also boiled for 10 minutes, cooled, sealed, and autoclaved to sterilize.

This quiz explores the various aspects of liquid dosage forms, focusing on solutions, their advantages, and disadvantages. It highlights the importance of solvent choice, particularly aqueous solutions, and examines the implications for drug absorption and storage. Test your knowledge on the characteristics and considerations of liquid medications.