Tableting lipid-based formulations for oral drug delivery: a case study with silica nanoparticle-lipid-mannitol hybrid microparticles.

Silica-lipid-mannitol hybrid (SLMH) microparticles have been developed that were compressible into high quality tablets suitable for oral dosing and delivery of poorly soluble drugs. SLMH tablets enable high lipid-loading levels (>40%) and retain the immediate release, enhanced lipase digestion and drug solubilisation performance. Specifically, we report formulation optimisation of SLMH microparticles and tablets using coumarin 102 (log P = 4.09) as a model Biopharmaceutics Classification System class II drug. SLMH tablets were acceptable according to standard British Pharmacopoeia friability, hardness and disintegration tests; this is not the case for conventional dry emulsions. Furthermore, in vitro dissolution and pancreatic-lipase-induced lipolysis studies under simulated intestinal conditions have demonstrated enzymatic-digestion-mediated drug solubilisation. SLMH microparticles and tablets are suitable as liquid lipid containing solid dosage forms for enhancing and controlling oral absorption of poorly soluble drugs.