Structure and properties of ibuprofen–hydroxypropyl methylcellulose nanocomposite gel

From a mixture of a methanol solution of ibuprofen (IB) and an aqueous solution of hydroxypropyl methylcellulose (HPMC), clear, uniform sol was obtained at the methanol/water proportion 7/3. When sol was brought to dryness, nanocomposite gel was obtained with amorphous IB particles of 20–50 nm dispersed in HPMC matrix. Simultaneous and quick nano-hybridization and amorphization are based on: (i) re-precipitation of IB in the restricted space of HPMC network, and (ii) recombination of hydrogen bonds from those within IB crystal to those between IB and HPMC. Associated change in the properties including dissolution into aqueous medium was discussed briefly in view of application feasibility to pharmaceutical processing.