Abstract
Continuing our studies on SVCT2 ascorbic acid (AA) transporter-mediated drug delivery of neurotropic agents, we have now investigated the in vitro intracellular uptake of Diclofenac (Diclo) and its conjugate (AA-Diclo), both characterized by high affinity for the SVCT2 transporter. We have also investigated the in vivo uptake mechanism of AA-conjugate of Nipecotic acid (AA-Nipec) and the implication of the transporter-mediated effects of Diclo and AA-Diclo. Diclo resulted as a noncompetitive inhibitor of AA transport, but also showed a sodium-dependent and ascorbate-independent uptake, thus implying the possible involvement of specific transporters in the delivery to the brain of Diclo. This result opens a perspective in the discovery of new strategies in the targeting of this drug to the brain. Inhibitory effects of Diclo and AA-Diclo on the SVCT2 transporter were used to study anticonvulsant effects of AA-Nipec, confirming our hypothesis of an SVCT2-mediated transport in its neurotropic activity. AA-Diclo stability has been also investigated: it is hydrolyzed following a first-order kinetics in buffer, plasma (t1/2 at about 10 h) and whole blood (t1/2 at about 3 h), suggesting AA-Diclo as a potential candidate to enhance the short half-life of Diclo in vivo.
Original language | English (US) |
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Pages (from-to) | 78-85 |
Number of pages | 8 |
Journal | Journal of Pharmaceutical Sciences |
Volume | 93 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2004 |
Keywords
- Active transport
- Ascorbic acid
- CNS
- Diclofenamic acid
- Nipecotic acid
- Prodrugs
- SVCT2
- Stability
- Transporters
ASJC Scopus subject areas
- Pharmaceutical Science