Pharmaceutical Formulation Basics

Questions and Answers

Which solvent has the highest dielectric constant at 25°C?

Water (correct)

Glycerol

Ethanol

Dimethyl sulfoxide

Which of the following solvents has the lowest dielectric constant at 25°C?

Dimethylacetamide

Cottonseed oil (correct)

Propylene glycol

Polyethylene glycol 400

What is the primary issue when using co-solvents in formulations?

Difficulty in solubility testing

High solubility of drugs

Cost of the solvents

Toxicity of the solvents (correct)

Which two co-solvents are most commonly used in injectable formulations?

Ethanol and propylene glycol Signup and view all the answers

How does the dielectric constant affect the solubility of poorly soluble drugs?

Lower dielectric constant enhances solubility Signup and view all the answers

What does a higher dielectric constant indicate about a solvent?

Better electric current conductivity Signup and view all the answers

What is the primary purpose of keeping sterile formulations as simple as possible?

To reduce safety risks and complexity Signup and view all the answers

What is considered the preferred solvent for injectable formulations?

Water for injection (WFI) Signup and view all the answers

Why are nonpyrogenic ingredients important in sterile drug formulations?

They ensure the finished product is free from pyrogens Signup and view all the answers

What type of solvents may be used for drugs that are not soluble in water?

Water-miscible organic co-solvents Signup and view all the answers

What is the role of additives in sterile drug formulations?

To serve as stabilizers or preservatives Signup and view all the answers

What defines 'parenteral grade' ingredients used in preparations?

Ingredients with very high purity Signup and view all the answers

What is the significance of establishing microbial and endotoxin limits?

To ensure safety for parenteral administration Signup and view all the answers

Which of the following is NOT a suitable component of an ideal parenteral formulation?

Multiple excipients Signup and view all the answers

What is the primary reason for using co-solvents in drug formulations?

To increase drug solubility Signup and view all the answers

What type of surfactants should ideally be used in parenteral preparations?

Non-ionic surfactants Signup and view all the answers

What is a critical requirement stipulated by the USP for antimicrobial agents in multiple-dose containers?

They must prevent the multiplication of microorganisms introduced during use. Signup and view all the answers

What maximum volume does the USP prescribe for antimicrobial agents used in parenteral products?

30 ml Signup and view all the answers

Why should buffering agents have a low buffering capacity in parenteral preparations?

To not significantly disturb the body’s buffering systems upon injection. Signup and view all the answers

Which of the following acids is commonly used as a buffering agent?

Citrates Signup and view all the answers

What effect can buffer components have on drugs in parenteral preparations?

They can catalyze the degradation of drugs. Signup and view all the answers

Which surfactants are often used to improve the dispersion properties of insoluble active drugs?

Non-ionic surfactants like Polysorbates Signup and view all the answers

What is the limitation regarding the usage of co-solvents in drug dosages greater than 5 mL?

Co-solvents may precipitate at the site of injection. Signup and view all the answers

Which of the following products contains the highest amount of polysorbate concentration?

AvastinⓍR Signup and view all the answers

What does the figure in the content demonstrate regarding co-solvents?

Co-solvent percentages affect the solubility of drugs. Signup and view all the answers

Which product has the lowest active ingredient concentration listed?

TisseelⓍ R Signup and view all the answers

When using co-solvents, what is a critical factor affecting drug administration?

The speed of drug administration can lead to precipitation. Signup and view all the answers

Which of the following drugs is presented in a lyophilized form with a concentration of 1 mg/mL?

ActivaseⓍ R Signup and view all the answers

What main risk is associated with co-solvents in drug formulation?

They may cause precipitation if injected too quickly. Signup and view all the answers

Which active ingredient has the highest concentration in the provided examples?

AralastⓍR Signup and view all the answers

What is a common characteristic of polysorbates in drug formulations?

They can stabilize proteins in liquid formulations. Signup and view all the answers

What is the primary purpose of bulking agents in freeze-dried products?

To facilitate handling and reconstitution Signup and view all the answers

Which of the following is NOT a commonly used suspending agent?

Sodium benzoate Signup and view all the answers

What role do emulsifying agents play in emulsions?

To stabilize the emulsion by reducing surface tension Signup and view all the answers

Which additive is typically used as a viscosity-inducing agent in topical ophthalmic solutions?

Hydroxypropyl methylcellulose Signup and view all the answers

What are liposomes primarily used for in drug formulations?

To incorporate and target active ingredients Signup and view all the answers

Which polymer is commonly associated with extended-release drug formulations?

Polylactic-polyglycolic polymers Signup and view all the answers

What is the function of wetting agents in suspensions?

To facilitate better contact between the drug and solvent Signup and view all the answers

Which of the following is an example of a surfactant used as a wetting agent?

Polysorbate 80 Signup and view all the answers

What is the primary function of specialized polymers in controlled-release dosage forms?

To modulate the release profile of drugs Signup and view all the answers

Which substance is commonly used as an emulsifying agent?

Egg yolk phospholipid Signup and view all the answers

Study Notes

Formulation Components

Sterile formulations should be simple, containing only the active ingredient, vehicle, and suitable container.
Additives (adjuvants, excipients) must be carefully selected for parenteral use to maintain quality.
A low microbial level is critical for effective sterilization and enhancing product safety.
"Parenteral grade" ingredients ensure high purity suitable for injectable formulations.

Vehicles (Solvents)

The primary solvent used in sterile drug formulations is Water for Injection (WFI).
For insoluble drugs, limited volumes of water-miscible organic co-solvents or oily solvent systems may be utilized.
Common co-solvents include ethanol and propylene glycol, which have dielectric constants conducive to solubilizing agents.

Solubilizing Agents

Co-solvents increase solubility but can be toxic in large dosages; acceptable limits apply.
A mixture of water and co-solvents can solubilize slightly polar drugs.
Surface-active agents (polysorbates) are crucial in improving drug dispersion in insoluble drug formulations.

Antimicrobial Agents

Antimicrobial agents must be present in adequate concentrations to prevent microbial growth in multi-dose containers.
Concentration limits for commonly used antimicrobials include thimerosal (0.01%), phenol (0.5%), and benzalkonium chloride (0.01%).

Buffers

Buffers are essential for maintaining pH and stability in drug formulations.
Common buffer systems include citrates, acetates, and phosphates; they should avoid significant interference with the body's pH balance.

Additional Additives

Additional solute additives serve various functions:
- Bulking agents for freeze-dried products (e.g., mannitol).
- Wetting and suspending agents for drug suspensions (e.g., sodium methylcellulose).
- Emulsifying agents for emulsions (e.g., lecithin).
- Viscosity-inducing agents for topical ophthalmic solutions (e.g., hydroxypropyl methylcellulose).

Specialized Delivery Systems

Controlled release systems utilize polymers like polylactic-polyglycolic acids for sustained drug delivery.
Innovative formulations can include liposomes for targeted drug distribution, enhancing therapeutic efficacy.

Examples from Commercial Products

Various products highlight concentrations of polysorbates used in formulations, indicating their application for different active ingredients and dosage forms.

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Description

This quiz covers the essential components and considerations in sterile pharmaceutical formulations. Focus on the role of vehicles, additives, and solubilizing agents important for parenteral preparations. Test your knowledge on the standards and practices ensuring safety and effectiveness in injectable drugs.