Complexation study of cinalukast and montelukast with cyclodextrines

A fluorimetric study on the spectral characteristics of two antileukotrienes, cinalukast and montelukast, has been performed. Ionization constants of both of them have been photometrically calculated. Cinalukast pK(a) in ethanol:water 50:50 (v/v) medium resulted to be 2.2+/-0.1. Because the spectral characteristics of montelukast are widely affected by the solvent nature, pK(a) was estimated in two different ethanol:water media, 70:30 (v/v) and 10:90 (v/v) and the values calculated were pK(a)=2.9+/-0.1, and pK(a1)=2.0+/-0.1 and pK(a2)=6.5+/-0.1, respectively. It has been proven that the fluorescence of both, cinalukast and montelukast, is significantly intensified in the presence of cyclodextrins (CyDs). The host-guest complexation processes between cinalukast and alpha-CyD or heptakis-(2,6-di-O-methyl)-beta-cyclodextrin (DIMEB) and between montelukast and DIMEB have been investigated by fluorescence spectroscopy. A 1:1 stoichiometric ratio was established for the three studied inclusion complexes. The changes produced on the fluorescence of cinalukast or montelukast, when they are included on the hydrophobic CyD cavity are used to calculate their association constants by a non-linear regression method. Semiempirical MO calculations using AM1 method were performed in order to characterize the studied inclusion complexes. A new method for cinalukast determination in human serum, based on the fluorescence of the complex cinalukast-DIMEB exhibiting limit of detection of 7.95 ng mL(-1) has been proposed with satisfactory results. Adequate recovery values between 95 and 103% were calculated at five different concentration levels.     

The link between allergic rhinitis and asthma: A role for antileukotrienes?

Allergic rhinitis and asthma are both chronic heterogeneous disorders, with an overlapping epidemiology of prevalence, health care costs and social costs in quality of life. Both are inflammatory disorders with a similar pathophysiology, and both share some treatment approaches. However, each disorder has an array of treatments used separately in controlling these atopic disorders, from inhaled corticosteroids, beta₂-agonists and antihistamines to newer monoclonal antibody-based treatments. The present article reviews the shared components of allergic rhinitis and asthma, and examines recent evidence supporting antileukotrienes as effective agents in reducing the symptoms of both diseases.