Long Acting Injectable Implants

Question 1

Why use Long acting injectable implants?

Answer 1

Extended release of drug at site which increases efficacy and reduces side-effects
Controlled delivery over one week to 6 months in a single injection
Biodegradable
Compatible with sensitive molecules like proteins
Low toxicity
Reduced number of operative procedures
Improved chance of desired therapeutic outcome

Question 2

What is an example of a long acting injectable thermal responsive implant?

Answer 2

OncoGel
Uses ReGel delivery system- PLGA
Paclitaxel treating solid tumours
Liquid below room temp ,gel at body temp

Question 3

What is an example of a long acting injectable solvent – removal precipitation implant system?

Answer 3

Atrigel system
Two separate syringes (atrigelcombined with drug)
Less invasive and biodegradable
Packaged with foil lined material to protect from moisture

Question 4

What drug is an example of a long acting injectable solvent – removal precipitation implant?

Answer 4

Atridox- Doxycycline

Question 5

What is the long acting injectable implant for HIV/aids prevention?

Answer 5

Cabenuva
Combination of two antivirals (cabotegravir and rilpivirine)
Two separate injections and combination reduces resistance

Question 6

Why are HIV drugs hard to formulate?

Answer 6

They are hydrophobic ideally should be water soluble
Drug burst initially with insatiable suspension and block the syringe via otswolld ripening

Question 7

What is ottswold ripening?

Answer 7

The expansion of small to large particles with heat

Question 8

What is an example of an injectable peptide mimetic hydrogel?

Answer 8

Ozempic
Structurally similar to GLP-1
Self assemble and nanofibrous gel that breaks down

Question 9

What is another example of an injectable peptide mimectic hydrogel?

Answer 9

Firmagon
Hormonal therapy
Suppresses testosterone
Solution when injected forms gel after subcutaneous administration
Formation based on concentration, time, temperature and salt content
Includes active ingredient and hydrogel forming platform

Question 10

What are the advantages of Long acting injectable implants?

Answer 10

Injection removes surgical need
Gels are easily sterilised via syringe filtration
High water content of the gel = better biocompatibility and less pain
The rate of sustained release can be easily controlled by adjusting the formulation composition
System is biodegradable via natural excretion

Question 11

Disadvantages of long acting injectables or implants and how to fix them with long acting injectable implants

Answer 11

Poor stability upon storage and transport- can transport as freeze dried powder and mixed with water before injection
Persistent pain months after injection -increased water content (aqueous water-based solvent)
Large needles- Formation fully soluble in water so can use narrower bore needles
Fast burst upon administration - hydro gel formation reduces burst release
Need for surgery- these implants are biodegradable