Determination of flowable liquid retention potential of aluminometasilicate carrier for liquisolid systems preparation

Context: Liquisolid systems are modern formulations used to increase the bioavailability of poorly water-soluble drugs. Their preparation is based on the sorption of a drug in liquid state onto a carrier with a high adsorption capacity. The carrier particles are subsequently coated with material having a large surface area to form free-flowing powder. The main principle of bioavailability increasing is based on the presence of the dissolved drug, which is ready for immediate absorption in GI tract. Objective: Determination of capability of aluminometasilicate carrier Neusilin® US2 to adsorb different solvents. Materials and methods: The maximum amounts of polyethylene glycol 200 (PEG 200), polyethylene glycol 400 and propylene glycol (PG), which can be sorbed by Neusilin® US2, while maintaining an acceptable flowability of the powder mixture, were evaluated using determination of the flowable liquid retention potential. Results and discussion: From the evaluation of liquisolid powder mixtures, it could be observed that 1 g of Neusilin® US2 can retain up to 1.00 g of PG, 1.16 g of polyethylene glycol 400 and 1.48 g of PEG 200, while maintaining acceptable flowing properties. Conclusion: Large specific surface area in combination with a high absorption capacity makes Neusilin® US2 suitable carrier for liquisolid system preparation.