Porous silica microparticles from diatomaceous earth (DE) for drug delivery applications

Abstract

Numerous mesoporous materials have been investigated in the last two decades to address therapeutic problems in drug delivery; for instance, poor bioavailability, low biodistribution, limited drug solubility, lack of selectivity and undesirable pharmacokinetics. In this work, a novel concept of using a silica-based natural mineral, referred to as diatomaceous earth (DE), as a drug carrier is explored. DE is formed from algae, a type of unicellular phytoplankton, through its silica shells (frustules) growth with ordered porous structures. To prove this concept we investigate loading and release of indomethacin, a poorly soluble drug from DE microparticles. The carrying capacity of DE was 22 wt % whereas indomethacin molecules in DE pores was released over a period of 12 days. This work demonstrates the application of DE microparticles as a drug carrier for sustainable release of drugs.