Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Binding Studies of Lamotrigine with Sera of Different Animal Species

Kalyan Kumar Sen¹ , Sanat Kumar Basu², Sadhan Kumar Dutta¹

¹Pharmacy Divisions, Gupta College of Technological Sciences, Ashram More, G.T. Road, Asansol-713301; ²Department of Pharmaceutical Technology, Jadavpur University, Kolkata-700032, India.

For correspondence:- Kalyan Sen Email: kkskpa@gmail.com Tel:+919932334958

Received: 25 October 2008 Accepted: 17 July 2009 Published: 23 October 2009

Citation: Sen KK, Basu SK, Dutta SK. Binding Studies of Lamotrigine with Sera of Different Animal Species. Trop J Pharm Res 2009; 8(5):409-415 doi: 10.4314/tjpr.v8i5.5

© 2009 The authors.
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Abstract

Purpose: The serum protein-binding characteristic of lamotrigine with sera from various species (horse, rat, rabbit and goat) was studied at different dielectric constants and temperatures to obtain an insight into the mechanism of interaction, evaluate the effect of dielectric constant on binding affinity, and to determine the effect of species variation on drug plasma-protein interaction.

Method: Binding data were generated by evaluating equilibrium dialysis of lamotrigine in methanol-water solvent (1:1 and 1:3) with horse serum at 20, 28 and 37 ⁰C The equilibrium dialysis evaluation of lamotrigine with sera of other animal species - rabbit, goat and rat - was also performed at 37 ⁰C.

Results: A Rosenthal plot obtained with the binding data at different temperatures showed that binding constant decreased with increasing temperature and that binding of lamotrigine to horse serum appeared to be saturation binding. The results also indicated that the binding process was characterized by negative DH⁰value and a small positive DS⁰ values. The binding constant decreased as dielectric constant rose.

Conclusions: The results obtained suggest that hydrophobic interaction may have occurred and that van der Waals’ forces were responsible for binding in the hydrophobic region. Data obtained for lamotrigine binding with horse, goat, rabbit and rat sera show that there are no significant changes in plasma protein binding in the above-mentioned species.

Keywords: Lamotrigine; Serum protein binding; Dielectric constant; Binding constant; Animal sera