Enhancement of Dissolution Rate of Piperine Using Solid Dispersion Approach and Evaluation of Its Antioxidant Activity.

Piperine is a phenolic compound in black pepper (Piper nigrum Linn) and Piper longum. It has been used in traditional medicine and has many pharmacological properties. However, its poor solubility in water has hindered the development of drugs with piperine as the main ingredient. In this study, solid dispersions of piperine were formulated using hydrophilic polymer (PVP) and hydrophobic polymer (Eudragit) to improve its dissolution rate and antioxidant activity. The solid dispersions were prepared using solvent evaporation techniques with various ratios of pure piperine to polymer (2:1, 1:1 and 2:1, w/w). FESEM, DSC, XRD, and FT-IR characterized the resulting solid dispersions of piperine. The dissolution rates were measured in distilled water, and antioxidant activity was evaluated using DPPH and FRAP free radical scavenging assays. The physicochemical characterization results indicated that solid dispersions with PVP and Eudragit had properties different from those of pure piperine. The dissolution test results showed that the solid dispersions with PVP (2:1) and Eudragit (1:1) exhibited the best dissolution rates, at 40.32 and 38.02 %, respectively. Furthermore, PVP and Eudragit solid dispersions (2:1, 1:1) demonstrated a higher antioxidant capacity in scavenger DPPH and FRAP free radicals than other formulations. These findings suggest that both polymers can increase piperine solubility, leading to increased antioxidant activity. However, further studies are needed to understand the underlying mechanisms. [ABSTRACT FROM AUTHOR]