Enhancing Flowability of Fine Cohesive Active Pharmaceutical Ingredients

Abstract

The effectiveness of pharmaceutical excipients and hydrophobic nano silica as flow regulator has been studied and two active pharmaceutical ingredients (API’s) i.e. paracetamol and ibuprofen are used to gauge the effectiveness. Avicel PH-101 and Avicel PH-102 are chosen as pharmaceutical excipients and Aerosil R972 pharma is used as hydrophobic nano silica, the API’s and the excipients are micro sized. Flow function, wall friction and bulk density tests to gauge the said effect are conducted on Brookfield Powder Flow Tester (PFT). The samples for testing are prepared by hand blending/manual mixing to ascertain the capability of simple inexpensive mixing in comparison to expensive blenders and machines. Ibuprofen and paracetamol are mixed with Avicel PH-101, Avicel PH-102 and Aerosil R972 pharma in different blend percentages and SAC% respectively. Scanning electron microscope images are taken to analyze the silica surface coverage and energy-dispersive X-ray spectroscopy technique is used to ascertain the presence of silica in API’s. The blended samples of paracetamol with Avicel PH-101 and Avicel PH-102 have shown great improvement in flowability in comparison to the blended samples of ibuprofen with Avicel PH-101 and Avicel PH-102. Mixing with nano-silica has drastically improved the flowability of ibuprofen coupled with significant improvement in paracetamol’s flowability. Wall friction characteristics of ibuprofen and paracetamol when blended with Avicel PH-101 and Avicel PH-102 have shown no significant change, however significant change is witnessed in nano blended samples. Compressibility of all blended samples generally decreased. Bulk densities of the samples blended with Avicel PH-101 and Avicel PH-102 decreased and of samples blended with nano silica it increased. The study conducted underlined the efficacy of the hand blending process by showing that significant improvement in flow properties can be brought about by it. PFT has confirmed the anticipated results of the powder blends indicative of its reliability, moreover repeatable results are obtained which established the repeatability of the instrument. A need for developing a low cost dry coating machine is felt and is thus fabricated and tests are carried on it to test its efficacy. Initial testing has shown encouraging results and further extensive testing needs to follow.