Spray Drying Polymer Dispersion for Pharmaceutical Coating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current pharmaceutical coating technologies face challenges in producing free-flowing powdery film coating agents with good redispersibility that maintain release behavior stability under prolonged or temperature-stressed storage, and they often result in undesirable agglomeration and high mechanical strength issues.
Innovation Solution
A process involving radical emulsion polymerization of N,N-diethylaminoethyl methacrylate and esters of α,β-ethylenically unsaturated mono- and dicarboxylic acids, followed by spray drying with controlled inlet and outlet temperatures to produce powders with specific glass transition and film-forming temperatures, ensuring the powders are free-flowing and redispersible without agglomeration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If spray drying is used to convert aqueous polymer dispersion into powder, then free-flowing powder with good redispersibility is obtained, but agglomeration occurs and mechanical strength increases undesirably
Solution Approach 1:
The patent applies parameter changes by carefully controlling the glass transition temperature (Tg) of the polymer to be between 40-80°C and the minimum film-forming temperature (MFFT) to be between 30-70°C. These specific temperature parameters prevent agglomeration during storage while maintaining low mechanical strength, resolving the contradiction between redispersibility and mechanical strength.
Solution Approach 2:
The patent uses composite materials by combining N,N-diethylaminoethyl methacrylate with specific esters of α,β-ethylenically unsaturated mono- and dicarboxylic acids. This composite polymer structure achieves the desired balance of redispersibility and low mechanical strength by incorporating both functional components in specific ratios.
2Reliability
If prolonged or temperature-stressed storage is applied to coating agents, then stability of release behavior is tested, but agglomeration occurs and redispersibility deteriorates
Solution Approach 1:
The patent applies beforehand cushioning by pre-setting the glass transition temperature and minimum film-forming temperature within specific ranges before storage. This preventive measure ensures that even under prolonged or temperature-stressed storage conditions, the powder maintains its redispersibility and release behavior stability without agglomeration.
3Strength
If high mechanical strength is achieved in powder coating, then coating durability improves, but unpleasant mouthfeel occurs due to coarse-grained disintegrants
Solution Approach 1:
The patent changes the mechanical strength parameter by controlling the polymer's glass transition temperature and minimum film-forming temperature to specific ranges, resulting in low mechanical strength that prevents coarse-grained disintegration. This eliminates the unpleasant mouthfeel while maintaining sufficient coating durability through the controlled polymer composition.
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 resulting powders are highly redispersible, maintain release behavior stability, and exhibit low mechanical strength, preventing unpleasant mouthfeel and ensuring rapid release in acidic environments while protecting moisture-sensitive active ingredients.
Implementation Method 1
spray-drying a polymer dispersion to produce coating solutions
Implementation Method 2
the inlet temperature of the drying gas is at least 20 °C above the glass transition temperature and at least 20 °C above the minimum film forming temperature
Implementation Method 3
radical emulsion polymerization of a monomer mixture containing N,N-diethylaminoethyl methacrylate
Implementation Method 4
the inlet temperature of the drying gas is at least 20 °C above the glass transition temperature
Implementation Method 5
converted an aqueous dispersion into a free-flowing powder with good redispersibility using a spray process
Data Source
AI summary
The invention relates to a method for producing powdery coating agents from aqueous polymer dispersions, containing i) as component A a polymer, obtained by radical polymerization, made of a) N,N-diethylaminoethyl methacrylate, and b) at least one radically polymerizable compound, selected among esters of a,ß-ethylenically unsaturated monocarboxylic and dicarboxylic acids containing C1-C8-alkanols, characterized in that the aqueous polymer dispersion is transferred into a powder by spray methods in the presence of a drying gas, wherein the input temperature of the drying gas in the spray device is at least 20ºC above the glass transition temperature and at least 20ºC above the minimum film formation temperature of the polymer, and the output temperature of the drying gas from the spray device is maintained at 40 to 85ºC.