Atorvastatin solid dispersion for bioavailability enhancement.

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems

Background:

• Atorvastatin calcium, a lipid-lowering agent, exhibits low bioavailability (approx. 15%).
• Poor solubility and dissolution limit the therapeutic efficacy of atorvastatin calcium.
• Undesirable adverse effects can arise from the unabsorbed portion of the drug.

Purpose of the Study:

• To enhance the solubility and dissolution profile of atorvastatin (AT) calcium.
• To develop an improved drug delivery system for atorvastatin calcium.

Main Methods:

• Solid dispersion (SD) technique was employed to improve atorvastatin calcium's properties.
• Conventional fusion method using polyethylene glycol 4000 (PEG 4000) as a hydrophilic carrier was utilized.
• Solubility and dissolution rates were evaluated using phosphate buffer (pH 6.8).
• Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC) were used for characterization.

Main Results:

• Solubility of atorvastatin calcium significantly increased in solid dispersion (93.66 ± 1.35%) compared to pure drug (55.33 ± 0.66%) and physical mixture (81.89 ± 2.35%).
• Solid dispersion formulation converted atorvastatin calcium from crystalline to amorphous form, confirmed by FTIR and DSC.
• Dissolution rate was significantly enhanced, with 91.66 ± 1.65% drug release at 1 hour for SD, compared to 28.92 ± 1.66% for pure drug and 72.16 ± 1.33% for a marketed tablet.

Conclusions:

• Solid dispersion formulation effectively enhances the solubility and dissolution profile of atorvastatin calcium.
• The developed solid dispersion shows superior performance compared to existing marketed preparations.
• This approach offers a promising strategy for improving the bioavailability and therapeutic outcomes of poorly soluble drugs like atorvastatin calcium.