(439b) Mesoporous Silica Particles for Formulation of Poorly Water Soluble Ingredients

Drug insolubility is one of the most challenging problems in the development of pharmaceutical products. Currently, over a third of drugs listed in US Pharmacopoeia and half of new chemical entities (NCEs) are classified as poorly water soluble or insoluble. Poor solubility in the digestive fluid will normally result in low bio-availability which in turn leads to irregular and incomplete absorption. The lack of success in commercialisation of such NCEs has been attributed to their poor solubility properties. As such, much effort has been put in to increase the dissolution rate of such poorly water soluble drugs. One approach is to produce the drugs in an amorphous form and thus increase its dissolution rate. However, the greatest drawback of working with amorphous drugs is that they are generally thermodynamically unstable and may revert back to their more stable crystalline form during storage and transport. In our work, we have overcome these difficulties by using ordered mesoporous silica particles, such as SBA-15, which possess high surface areas and pore volumes to attain a rapid dissolution rate property. A poorly water soluble drug, such as ibuprofen or fenofibrate, is typically co-spray dried with mesoporous SBA-15 to produce a solid dispersion. The amorphous state of the drug is achieved by the quick drying of the spray drying method and is confined within the pore channels of the mesoporous structure. Dissolutions tests show that the dissolution rate of the formulated drug is enhanced and would improve its absorption in the digestive tract and thus its efficacy. As the drug is contained within the nanospaces of the mesoporous structures and enclosed by thick pore walls, re-crystallisation of the drug is prevented, even under stress test conditions. The co-spray drying process could offer much potential in the formulation of other such poorly water soluble drugs which may otherwise find much difficulty in commercialisation.