Dry Powder Mixing Process for Inhalation Formulations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for preparing dry powder inhalation formulations, such as those containing tiotropium bromide, are inefficient and labor-intensive, requiring numerous steps and handling challenges due to the need for precise mixing and handling of small drug amounts, which affects flow characteristics and content uniformity.
Innovation Solution
A process involving the splitting of lactose carrier into three portions, layered mixing with the drug, and subsequent blending to achieve a preblend, followed by mixing with the remaining lactose portions, simplifies the preparation while ensuring excellent flow characteristics and content uniformity using a Turbula mixer and specific lactose particle size distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional blending methods are used to mix drug and excipient, then mixing is achieved, but the number of handling steps increases and content uniformity becomes difficult to ensure
Solution Approach 1:
The excipient is divided into multiple size fractions (coarse, medium, fine particles) which are then sequentially added to the drug in a specific order. This segmentation allows each fraction to contribute differently to the mixing process, ensuring both efficiency and uniformity without excessive handling steps.
Solution Approach 2:
The drug is pre-mixed with the coarsest excipient fraction first to create a homogeneous preblend before adding finer fractions. This preliminary action ensures the drug is evenly distributed in the coarse fraction, which then serves as a uniform base for subsequent mixing steps, reducing the total number of operations needed.
2Ease of operation
If coarse excipient particles are used to improve flow characteristics, then flow properties improve, but drug liberation in the lungs is negatively influenced
Solution Approach 1:
The excipient is segmented into different particle size fractions that are added sequentially. Coarse fractions are added first to establish good flow characteristics, followed by medium and fine fractions that ensure proper drug liberation in the lungs. This multi-level segmentation resolves the contradiction between flow and liberation.
Solution Approach 2:
Different regions of the powder mixture have different particle size distributions. The coarse fractions provide flow properties in the bulk material, while fine fractions associated with drug particles ensure proper aerosolization and lung deposition. Each fraction performs its specific function locally.
3Manufacturing precision
If multiple mixing steps are used to ensure content uniformity, then uniformity improves, but the process becomes labor-intensive and complex
Solution Approach 1:
The mixing process is segmented into distinct stages with specific fractions added at each stage. This structured segmentation simplifies the overall process by breaking it into manageable steps with clear objectives, reducing complexity while maintaining uniformity.
Solution Approach 2:
A preblend is created in advance by mixing the drug with coarse excipient fractions before final formulation. This preliminary action simplifies the subsequent mixing steps and reduces the overall complexity of the process while ensuring content uniformity is achieved.
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
This process significantly reduces the number of handling steps and ensures high content uniformity and flow characteristics, making the preparation of dry powder inhalation formulations more efficient and robust, as demonstrated by the examples showing excellent assay, relative standard deviation, and acceptance values.
Implementation Method 1
blending the three-layered composition obtained in step (b) to obtain a preblend
Data Source
AI summary
The present invention relates to a simple, robust and effective process for preparing a dry powder inhalation formulation containing at least one drug, preferably a highly active drug, more preferably Tiotropium bromide or Tiotropium bromide monohydrate, and a lactose carrier. The process is characterized in that a three-layered composition containing a drug layer in between layers of the lactose carrier is mixed and the obtained preblend is mixed with additional lactose carrier. The process combines a simple manufacturing procedure with an excellent content uniformity obtained over a wide range of mixing parameters.