12 Questions
What is the primary objective of controlled-release or modified-release products?
To achieve and maintain optimum therapeutic blood levels of a drug
What is the duration of drug release for the estradiol vaginal ring insert (Estring, Pharmacia & Upjohn)?
3 months
What is the mechanism of rate-controlled delivery systems?
Features of the device rather than physiological or environmental conditions
What is the primary difference between targeted release and rate-controlled delivery?
Targeted release isolates or concentrates a drug in a body region, tissue or site, while rate-controlled delivery controls the rate of drug delivery
What is the classification of controlled-release products according to the USP?
Extended release and delayed-release
What is the primary purpose of a delayed-release dosage form?
To release the drug at a time other than promptly after administration
What is the duration of drug release for levonorgestrel subdermal implants (Nor-plant System, Weth-Ayerst)?
5 years
What is the main difference between an extended-release dosage form and a conventional dosage form?
The dosage frequency
What is the typical release pattern of an extended-release product?
Immediate release of the drug followed by a gradual release
What is a potential disadvantage of extended-release dosage forms?
Loss of flexibility in adjusting the drug dose
What is the term used to describe the sudden and total release of the drug from an extended-release dosage form?
Dose dumping
What is the benefit of extended-release dosage forms in terms of drug blood levels?
Reduced fluctuations in drug blood levels
Study Notes
Controlled/Targeted Drug Release Delivery Systems
Characteristics of Controlled-Release Products
- Designed to release medication in a controlled manner, at a predetermined rate, duration, and location
- Aim to achieve and maintain optimum therapeutic blood levels of a drug
Non-Oral Controlled-Release Delivery Systems
- Include ocular, parenteral, subdermal, vaginal, and transdermal products
- Examples: estradiol vaginal ring insert (Estring, Pharmacia & Upjohn), levonorgestrel subdermal implants (Nor-plant System, Weth-Ayerst)
Targeted Release
- Isolates or concentrates a drug in a body region, tissue, or site for absorption or for drug action
Rate-Controlled Delivery
- Applied to certain types of drug delivery systems where the rate of drug delivery is controlled by device features rather than physiological or environmental conditions
- USP differentiates rate-controlled products as extended release and delayed-release
Extended Release vs. Delayed Release
- Delayed-release dosage form: designed to release the drug at a time other than promptly after administration
- Extended-release dosage form: allows for a reduction in dosing frequency compared to conventional dosage forms
Slow Release
- Synonyms: prolonged action (PA), sustained action (SA), long acting (LA), controlled-release (CR), extended release (ER), sustained release (SR)
- Provides an immediate release of the drug followed by gradual and continual release of additional amounts of drug
Advantages of Extended-Release Products
- Reduction in drug blood level fluctuations
- Reduction in dosing frequency
- Enhanced patient convenience and compliance
- Reduction in adverse side effects
- Enhanced therapeutic benefit
- Reduction in overall health care costs
Disadvantages of Extended-Release Products
- Loss of flexibility in adjusting the drug dose
- Increased risk of sudden and total drug release or “dose dumping” due to technology failure or patient misuse
Test your knowledge on controlled-release or modified-release products, designed to release medication in a controlled manner, at a predetermined rate, duration, and location. This quiz covers the concepts of orally administered and non-oral controlled-release delivery systems, including ocular and parenteral routes.
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