Wacker presents high-density pyrogenic silica for pharmaceutical applications

At the recently concluded CPhl Worldwide 2019, Wacker, the Munich-based chemical group, has debuted the pyrogenic silica HDK N20P Pharma. The product is designed as an excipient for pharmaceutical applications. Even in low amounts, it is equipped with the capability to enhance the flow characteristics of powder blends, absorbs moisture from hygroscopic solids, and serves as a tablet disintegrant. The new grade’s feature high tap density, which provides tangible logistics and handling benefits for pharmaceutical manufacturers. 

With HDK N20P Pharma, Wacket expanded its range of pyrogenic silicas designed for pharmaceutical and food applications. The new product is a compressed version of the HDK N20 Pharma grade, which has been employed in the pharmaceutical industry for several years. 

Both grades are hydrophilic pyrogenic silicas; their surfaces are thus wettable by water. Apart from the tap density, they possess the same physical-chemical properties. With a silicon-dioxide content of at least 99.8%, both products are “highly pure” and meet the specifications of the European and the US Pharmacopeia. 

Pyrogenic silicas are bulky white powders. In the manufacture of the new HDK grade, the flame process, in which the pyrogenic silica is made, is followed by a compression step. At approximately 100g per litre, HDK N20P Pharma is able to achieve a tap density that is slightly more than double that of its uncompressed counterpart. 

The high degree of compaction has a positive effect on logistics and handlong of the product. The media used to transport HDK N20P Pharma can now be filled with twice the amount of product. This halves the number of bags to be transported, and thus the volume of packaging. The packaging-material savings furthermore reduce environmental pollution. There is also less dust produced when the bags are emptied, and the compressed pyrogenic silica is processed. Correspondingly, less cleaning is required. In addition, the product is easier to meter due to its compactness. 

HDK N20P Pharma is used as a processing auxiliary in the manufacture of pharmaceutical powders, pellets and tablets. The pyrogenic silica enhances the flow characteristics of powders and can bind moisture. These effects make pharmaceutical powders easier to process. HDK N20P Pharma furthermore accelerates tablet disintegration. Amounts of less than 1% are typically sufficient to achieve these effects, the company said.