Montmorillonite as a drug delivery system: Intercalation and in vitro release of timolol maleate

The need for safe, therapeutically effective, and patient-compliant drug delivery systems continuously leads researchers to design novel tools and strategies. Clay minerals play a very crucial role in modulating drug delivery. This work examines the advantageous effect of clay mineral as drug carrier for timolol maleate (TM), a nonselective beta-adrenergic blocking agent. The intercalation of TM into the interlayer of montmorillonite (MMT) at different pH and initial concentration is demonstrated. MMT-TM hybrid was characterized by X-ray diffraction (XRD), Fourier transformed infrared (FT-IR), and thermal analysis (TG-DTA). TM was successfully intercalated into the interlayer of MMT, and in vitro release properties of the intercalated TM have been investigated in simulated gastric fluid (pH 1.2) and simulated intestinal fluid (pH 7.4) at 37+/-0.5 degrees C. Controlled release of TM from MMT-TM hybrid has been observed during in vitro release experiments.