Revista Egitania Sciencia - Volume 18 | ARTICLE

Title: DETERMINING THE DISSOCIATION CONSTANT AND PARTITION COEFFICIENT OF PHARMACEUTICAL IONIC LIQUIDS WITH ANTI-INFLAMMATORY ACTIVITY

Author: Alexandre Marques (alexchelsea1@hotmail.com), Ana Dias (anafilipavd3@hotmail.com), André R.T.S. Araujo (andrearaujo@ipg.pt), Ana Azevedo (aazevedo@ff.up.pt), Paula Pinto (ppinto@ff.up.pt), M. Lúcia M.F.S. Saraiva (lsaraiva@ff.up.pt)

Publication: Revista Egitania Sciencia - Volume 18

Abstract:
Ionic liquids (ILs) have shown great potential in a number of laboratory and industrial settings. These compounds are generally defined as organic salts consisting of an organic cation and an organic or inorganic anion with melting points below 100 °C. In the present study, the interaction of ILs containing the cation choline and the anions ibuprofenate, naproxenate and ketoprofenate were evaluated with human serum albumin (HSA) by spectrofluorometry. HSA was selected as it is the protein most abundant in plasma and due to its intrinsic fluorescence, that can be reduced by interaction of drugs, allowing the evaluation of binding affinity to plasmatic proteins by the ILs-APIs (Active Pharmaceutical Ingredients). 174 Simultaneously, the partition of the three ILs-APIs was analyzed between the aqueous and lipid phases, formed by micelles of hexadecylphosphocholine, that were used due to theirstructural similarity to the lipids present in biological membranes. Through this assay the partition coefficient (Kp) was calculated by derivative spectrophotometry in the ultraviolet-visible region.
The HSA binding affinity results revealed that choline naproxenate establishes a stronger binding with HSA in comparison with the reference drug, naproxen. In the Kp determination assays an increasing of the partition of choline ibuprofenate was observed in relation to ibuprofen, suggesting an improvement in the ability to pass through biological membranes.


Keywords: pharmaceutical ionic liquids; dissociation constant; partition coefficient; spectroscopic methodologies




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