Preparation and Crystal Modification of Ibuprofen-Loaded Solid Lipid Microparticles

An emulsion-congealing technique is used to prepare solid lipid microparticles （SLM） containing ibuprofen with glyceryl behenate, tripalmitin and beewax as excipients. The difference of the solubility parameters between the excipients and ibuprofen are used to analyze their compatibility. Both the solubility parameter analysis and the experimental results show that glyceryl behenate is the best among the three excipients. The solid particles disperse well in aqueous phase when the drug loading reaches 10% （relative to lipid only）. Glycerides exhibit marked polymorphism and their rapid rates of crystallization accelerate the formation of metastable crystal modification. The metastable crystal modification characterizes high drug loading capacity but less stability. Increasing the content of lipophilic drug in a lipid matrix facilitates the transformation of excipients to more stable polymorphic forms.

High drug loading polymer micelle@ZIF-8 hybrid core–shell nanoparticles through donor–receptor coordination interaction for pH/H_(2)O_(2)-responsive drug release

Smart drug delivery nanocarriers with high drug loading capacity are of great importance in the treatment of diseases,and can improve therapeutic effectiveness as well as alleviate side effects in patients.In this work,a pH and H_(2)O_(2)-responsive drug delivery platform with high doxorubicin(DOX)loading capacity has been established through coordination interaction between DOX and phenylboronic acid containing block polymer.A composited drug nanocarrier is further fabricated by growing a zeolitic imidazolate framework 8(ZIF-8)on the surface of drug-loaded polymer micelles.The study verifies that ZIF-8 shell can act as intelligent“switch”to prevent DOX leaking from core–shell nanoparticles upon H_(2)O_(2) stimulus.However,a burst drug release is detected upon pH and H_(2)O_(2) stimuli due to the further disassociation of ZIF-8 in acid solution.Moreover,the in vitro anti-cancer experiments demonstrate that the DOX-loaded core–shell nanoparticles provide effective treatment towards cancer cells but have negligible effect on normal cells,which results from the high concentration of H_(2)O_(2) and low pH in the microenvironment of tumor cells.