Development and characterization of gastro-floating sustained-release capsule with improved bioavailability of levodopa.

In this study, a new gastro-floating sustained-release capsule (GFC) with levodopa (LD) and benserazide hydrochloride (BH) was successfully developed. GFCs were prepared by filling the LD and BH granules into hard capsules and coated with cellulose acetate (CA) solution as a controlled-release layer. The effects of formulation factors on the release of GFCs were conducted. The AUC 0~24 (µg h/mL) of LD were 69.31 ± 3.61 (μg h/mL) and 28.87 ± 2.58 (μg h/mL) and the C max were 7.84 ± 0.34 (μg/mL) and 9.21 ± 1.04 (μg/mL) in the GFCs and commercial tablets respectively. The relative bioavailability of LD was 267.55 ± 34.54%. Compared with commercial tablets, the pharmacokinetic study indicated that the developed GFCs provided a better sustained-release effect and higher bioavailability than commercial tablets.