Pharmacokinetic evaluation of formulated levodopa methyl ester nasal delivery systems.

The objective of this study was to investigate the pharmacokinetic characteristics of levodopa (L-dopa) from nasal powder formulations using highly water-soluble levodopa methyl ester hydrochloride (LDME). In vivo pharmacokinetic studies were carried out with formulated LDME nasal powders. After oral and intravenous administration of L-dopa and carbidopa and intranasal administration LDME to the rat, L-dopa concentrations were determined in plasma and the brain using high-performance liquid chromatography.

Design and evaluation of levodopa methyl ester intranasal delivery systems.

Objectives: This study aimed to examine the feasibility of nasal powder formulations for the delivery of levodopa (L-dopa) into the brain using highly water-soluble levodopa methyl ester hydrochloride (LDME).

Methods: For designing nasal LDME powders, pH-rate stabilities of LDME in buffer solutions and their enzymatic degradations in rabbit nasal mucosal and serosal extracts were investigated. In vitro permeation studies were carried out with four LDME nasal powders.

Interaction between warfarin and Korean red ginseng in patients with cardiac valve replacement.

Background: The objective of this study was to determine whether an interaction exists between warfarin and Korean red ginseng.

Methods: A prospective, double-blind, randomized, two-period crossover study was conducted on 25 patients with cardiac valve replacement under warfarin therapy. Either Korean red ginseng 1 g or placebo (hop extract 0.

Pharmacokinetic evaluation and modeling of formulated levodopa intranasal delivery systems.

Levodopa (L-dopa), the metabolic precursor of dopamine, has primarily been used for the treatment of Parkinson's disease (PD) in combination with carbidopa (C-dopa). This study aims to investigate the feasibility of L-dopa nasal delivery systems prepared using maleic acid solution containing 2-hydroxypropyl-beta-cyclodextrin, and to develop pharmacokinetic models. Following oral or intravenous administration of L-dopa plus C-dopa and intranasal dosing of L-dopa in the presence and absence of C-dopa to the rat, the concentrations of L-dopa in plasma and brain were determined using HPLC.