Pharmacokinetic evaluation of formulated levodopa methyl ester nasal delivery systems.

Yeon Hong Lee, Kyung Hee Kim, In Kyung Yoon, Kyung Eun Lee, In Koo Chun, Jeong Yeon Rhie, Hye Sun Gwak

Index: Eur. J. Drug Metab. Pharmacokinet. 39(4) , 237-42, (2014)

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Abstract

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. The absolute bioavailabilities of nasal preparations with and without Carbopol were 82.4 and 66.7 %, respectively, which were much higher than that of oral delivery (16.2 %). The drug-targeting efficiencies [area under the curve (AUC) in brain/AUC in plasma] of L-dopa in the nasal formulations (0.98-1.08) were much higher than that of oral preparation (0.69). These results suggest that LDME nasal powder formulations would be useful delivery systems of L-dopa to the brain.