Powder mixing device, and uses thereof

#The disclosure relates to powder mixing devices of the type referred to as blenders, for use in various industries wherein it is required to intimately blend powdered or granular solid materials with other solid or liquid materials. More particularly, the subject disclosure relates to a device and its uses to mitigate tribocharging in powders encountered during blending or mixing process.

#Pharmaceutical industry involves handling of powders on a large scale for manufacturing of solid dosage forms as they constitute 85% of the dosage forms due to their ease of manufacturing, packaging, longer shelf life, alterable drug release profiles, and high patient compliance. In order to manufacture a tablet, powders are processed through multiple unit operations such mixing, milling, granulation, drying and pneumatic transport. Mixing of powders is a common procedure employed in multiple industries including food, automotive, defense, cosmetics, polymer, agriculture, printing, and pharmaceuticals. The efficiency of these unit operations governs quality of the final product. During these unit operations powders get charged due to particle-particle collisions and particle-equipment wall collisions, impacting the performance of blending process. Electrostatic charging via contact electrification or tribocharging refers to the process of charging of two solid surfaces when they are brought into contact and separated. Considerable charge generation significantly affects granular flows creating industrial storage problems, jamming, segregation, and unfortunately, industrial fire explosions due to electrostatic discharge in the presence of volatile organic solvents.

#Disclosed is a mixing vessel, including: a first segment having a first work function; and a second segment having a second work function that differs from the first work function, wherein the mixing vessel is configured for mixing a powder having a third work function that is between the first and second work functions.

#Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

#FIG. 1 shows a schematic representation of a V-shaped Blender.

#FIG. 2 shows a schematic representation of a V-shaped Blender with each arm made from different component.

#Triboelectrification being one of the primary reasons of dust explosions in particulate industry, necessitates an option to reduce charge generation during dynamic processes. Techniques implemented in the industry, often fail to mitigate charging. Stop-gap reforms are often implemented, or the processing techniques are modulated to accommodate such charge accumulation, without full proof risk mitigation. The disclosed embodiments reduce these dust explosions thereby increasing the occupational safety. Pharmaceutical powders are mixed (or blended) with excipients during manufacturing in particular amounts can lead to decrease in Tribocharging. However, it is required to use large amounts of excipients which could lead to high cost of manufacturing and there is always a risk of drug-excipient incompatibilities. It is also known that toxicity of excipients is different in pediatric population and therefore, it is important to perform toxicity studies in different patient populations which further requires time and money. Equipment grounding is a common practice to reduce electrostatic charging during powder processing, but as pharmaceutical materials are insulators with low conductivity (10−12 S/cm) relative to metals (107 S/cm), this practice is not very efficient for insulator powders.

#The disclosed embodiments target to mitigate tribocharging in powders encountered during blending or mixing process. APIs (active pharmaceutical ingredients) have low solubility leading to low dissolution rates which necessitates that they are milled or micronized to improve dissolution. During micronization APIs gets extensively charged. The charging of different powders could result from ion, electron or material transfer. However, it is difficult to predict the mechanism responsible for charging of pharmaceutical powders as most of them are insulators and they do not possess free electrons to release. Thus, the insulator surfaces often maintain abundance of charges created by tribocharging. A powder mixing device is fabricated using a combination of insulator and metal (with significantly different work functions) materials which demonstrated significant reduction in charge of the powder being blended. The blender can be of any suitable size and shape, for example as shown in FIGS. 19A-19E, a V-shaped blender 110, a cylindrical blender 110, a double cone blender 110, a tote blender 110 or bin blender 110. In the illustrated embodiments, the blender 110 is a V-shaped blender. The blenders have support frames 111 and controllers 112 that are typically utilized for supporting and controlling the blenders 110.

#Turning to FIG. 1, in certain embodiments, the powder mixing system 100 (FIG. 9) includes a V-shaped container (for simplicity, a container 110) having diagonally disposed first and second cylindrical arms (for simplicity, first and second arms) 110A, 110B, generally referred to as arms 110A, 110B. The first and second arms 110A, 110B are also referred to herein as first and second segments or components of the container 110.