Development and characterization of clarithromycin-smectite hybrid for burst release at high pH condition

In this study, we developed and characterized a clarithromycin (CLR)-intercalated smectite hybrid and demonstrate that it holds great potential as an effective drug-carrier for local delivery of CLR. The intercalation of CLR into a smectite interlayer was examined at 0.4-4.0 mg ml^-1 of CLR solution at pH 5. The developed CLR-intercalated smectite hybrid was characterized using x-ray diffraction (XRD), UV-vis spectroscopy, energy dispersive x-ray spectroscopy (EDS), thermogravimetric-differential thermal analysis (TG-DTA) and Fourier transform infrared spectroscopy (FT-IR). Intercalation of CLR was confirmed by an increase in the d-spacing in the XRD pattern and the ether absorbance band in the FT-IR spectrum for the CLR hybrid. An in vitro release study demonstrates that most of the CLR was released from the hybrid in both low pH condition (pH 1.2) and high pH condition (pH 7.4) fluids within 60 min. Compared with the conventional tablet form, approximately 4-times more CLR was released within 1 h at high pH conditions, indicating suitable local therapeutic performance. Therefore, Helicobacter pylori, which is located only in the gastric mucosal layer could be a good target organism for this hybrid. In conclusion, smectite could be a suitable carrier for local delivery of intercalated drug, and CLR intercalated smectite could be a new option for local therapy of gastrointestinal conditions.