Triamcinolone Acetonide Suspension for Intravitreal Injection
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Solution Overview
Problem
Current triamcinolone acetonide suspension formulations for eye injections, such as Kenalog-40 Injection, settle rapidly, contain preservatives that can irritate the eye, and are difficult to inject through small needles, limiting their usability and safety for treating conditions like diabetic macular edema.
Innovation Solution
Aqueous suspension compositions with low viscosity, high degree of flocculation, and preservative-free, containing triamcinolone acetonide, carboxymethylcellulose, polysorbate 80, and pharmaceutically acceptable tonicity-adjusting chloride salts, which can be easily resuspended and injected through 27-gauge or 30-gauge needles, and are terminally sterilizable by autoclaving.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional triamcinolone acetonide suspension formulations (e.g., Kenalog-40) are used, then the suspension provides therapeutic effect, but the particles settle rapidly and are difficult to resuspend
Solution Approach 1:
The patent modifies the surfactant concentration parameter to a relatively low amount (specifically polysorbate 80 at 0.02-0.04% w/v), which changes the interfacial properties and promotes flocculation. This parameter change transforms the suspension from a deflocculated state (rapid settling, hard to resuspend) to a flocculated state (controlled settling, easy to resuspend with gentle shaking), resolving the contradiction between stability and ease of operation.
2Reliability
If conventional triamcinolone acetonide suspension formulations are used, then the suspension provides therapeutic effect, but the formulation contains preservatives that can irritate the eye
Solution Approach 1:
The patent removes (extracts) the preservative component from the formulation entirely, creating a preservative-free suspension. The low surfactant concentration and flocculated structure enable the suspension to remain stable without preservatives, eliminating eye irritation while maintaining therapeutic efficacy through the controlled flocculation and low viscosity characteristics.
3Reliability
If conventional triamcinolone acetonide suspension formulations are used, then the suspension provides therapeutic effect, but the viscosity is high making injection through small needles difficult
Solution Approach 1:
The patent changes the viscosity parameter by adjusting the surfactant concentration to a low level and promoting flocculation, resulting in a suspension with reduced viscosity that can be easily injected through 27-gauge or 30-gauge needles. The flocculated structure allows the suspension to maintain stability while achieving lower viscosity for easier injection, resolving the contradiction between therapeutic efficacy and injection ease.
4Ease of operation
If the surfactant amount is reduced to improve flocculation, then the suspension becomes easier to inject and process, but the suspension may become less stable
Solution Approach 1:
The patent optimizes the surfactant concentration parameter to a specific low range (0.02-0.04% w/v), which is sufficient to maintain suspension stability through controlled flocculation while being low enough to reduce viscosity and improve ease of processing and injection. This precise parameter optimization resolves the contradiction between stability and ease of operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The improved suspension compositions exhibit excellent settling characteristics, are easily processed, and can be smoothly injected, providing effective treatment options for eye conditions like diabetic macular edema without rapid settling or preservative irritation, enhancing treatment efficacy and safety.
Implementation Method 1
a triamcinolone acetonide suspension composition containing a relatively low amount of surfactant has superior flocculation properties
Implementation Method 2
The improved aqueous suspension compositions have excellent settling characteristics
Implementation Method 3
containing triamcinolone acetonide, carboxymethylcellulose, polysorbate 80
Implementation Method 4
the suspension compositions of the present invention can be terminally sterilized by autoclaving
Data Source
AI summary
Triamcinolone acetonide suspension compositions are disclosed. The suspension compositions have a relatively low viscosity and are easy to extrude through a 27- or 30-guage needle but are highly flocculated and easily redispersed. The compositions are particularly suitable for intravitreal injection.