Dissolution enhancement of a model poorly water-soluble drug, atorvastatin, with ordered mesoporous silica: comparison of MSF with SBA-15 as drug carriers

ABSTRACT

Objectives: The purpose of this study was to develop mesoporous silica materials incorporated with poorly water-soluble drug atorvastatin calcium (AC) in order to improve drug dissolution, and intended to be orally administrated. A comparison between 2D-hexagonal silica nanostructured SBA-15 and mesocellular siliceous foam (MSF) with continuous 3D pore system on drug release rate was investigated.

Methods: AC-loaded mesoporous silicas were characterized thorough N₂ adsorption-desorption analysis, Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and dynamic light scattering (DLS).

Results: Results demonstrated a successful incorporation of AC into the silica-based hosts. The results taken from the drug release tests were also analyzed using different parameters, namely similarity factor (f₂), difference factor (f₁), dissolution efficiency (DE%), mean dissolution rate (MDR) and dissolution time (t_m%). It confirmed a significant enhancement in the release profile of atorvastatin calcium with SBA-15, and MSF as drug carrier. Moreover, in comparison with SBA-15, MSF showed faster release rate of AC in enzyme-free simulated gastric fluid (pH 1.2).

Conclusion: We believed that our findings can help the use of mesoporous silica materials in improving bioavailability of poorly water-soluble drugs.

KEYWORDS:

• Atorvastatin
• dissolution rate
• drug release mechanism
• mesoporous silica materials
• poorly water-soluble drug