Smart phase transformation system based on lyotropic liquid crystalline@hard capsules for sustained release of hydrophilic and hydrophobic drugs

Smart phase transformation systems@hard capsule (SPTS@hard capsule) based on lyotropic liquid crystalline (LLC) were developed for oral sustained release in this study. Doxycycline hydrochloride (DOXY) and meloxicam (MLX) were used as hydrophilic and hydrophobic model drug, respectively. Two systems were added with different additives, that is, gelucire 39/01, PEG 1000 and Tween 80 to adjust their melting point and release profiles. The phase transformation of these systems could be triggered by water as well as temperature. They could spontaneously transform into cubic phase or hexagonal phase when coming across with water, to achieve the 24 h sustained release profile. In addition, the obtained systems could switch between semisolid state and liquid state when temperature changed within room temperature and body temperature, which facilitated the phase transformation in gastrointestinal tract and during their encapsulation into hard capsules. LLC-based SPTS@hard capsule revealed potential for the industrialization of its oral administration on account of its drugs accommodation with different solubility, controllable release profile and simple preparation process.