A novel blending method for dispensing powdered medicine

Area of Science:

• Pharmaceutical Technology
• Materials Science
• Process Engineering

Background:

• Manual blending of powdered medicines by pharmacists can lead to individual variations in skill, impacting drug uniformity.
• Developing automated, consistent methods for pharmaceutical powder blending is crucial for quality control and patient safety.

Purpose of the Study:

• To evaluate the efficacy of a planetary centrifugal mixer for blending powdered medicines.
• To determine optimal operational parameters for the mixer to achieve uniform drug blending.
• To compare the mixer's performance against manual blending methods.

Main Methods:

• Investigated blending performance using colored and crystalline lactose as model compounds.
• Assessed blending uniformity via image analysis, quantifying with relative standard deviation of color difference (Cb value).
• Explored operational variables: speed (400-1000 rpm), time (10-60 s), charging rate (20-50%), and vessel size (35-550 mL).

Main Results:

• Sufficient blending achieved at 10s with a 20% charging rate and 35 mL vessel, independent of speed.
• Higher charging rates and larger vessel sizes necessitated increased operational speeds for uniform blending.
• Uniform blending was consistently achieved across various weight ratios (1:9 to 9:1) of model drug and diluent.
• Application studies with commercial drugs (Adona®, Anginal®, Neophylline®) showed comparable blending performance to manual methods (RSD 2.2-3.8%).

Conclusions:

• The planetary centrifugal mixer is a suitable and effective tool for blending powdered medicines.
• The study provides insights into optimizing mixer parameters for consistent pharmaceutical powder preparation.
• Automated blending with this mixer enhances drug uniformity and reduces reliance on manual technique variability.