Complexation study of cinalukast and montelukast with cyclodextrines

Montelukast medicines of today and tomorrow: from molecular pharmaceutics to technological formulations

Montelukast sodium is a leukotriene antagonist of growing interest as an alternative therapy for asthma across different age groups due to its bronchoprotective, anti-inflammatory and anti-allergic properties. Currently, montelukast is commercialized only in oral solid dosage forms, which are the favorite of adult patients but may pose challenges in administration to children of young age or patients suffering from dysphagia. This review presents a comprehensive revision of scientific reports and patents on emerging strategies for the delivery of montelukast. A common ground to these reports is the pursue of an enhanced montelukast performance, by increasing its bioavailability and physico-chemical stability. A wide variety of strategies can be found, from the formation of supramolecular adducts with cyclodextrins to encapsulation in nanoparticles and liposomes. The new dosage forms for montelukast are designed for non-enteric absorption, some for absorption in the oral cavity and another two being for local action in the nasal mucosa or in the pulmonary epithelium. The review describes the emerging delivery strategies to circumvent the current limitations to the use of montelukast that are expected to ultimately lead to the development of more patient-compliant dosage forms.

Spectrofluorimetric determination of the antineoplastic agent lomustine based on the sensitizing effect of β-cyclodextrin

The effects of solvent dipolarity/polarizability and solvent-solute hydrogen bonding on the photophysical properties of the antineoplastic drug lomustine were analysed by means of the linear solvation energy relationship (LSER) concept proposed by Kamlet and Taft. The LSER method enabled the overall solvent effects to be quantitatively estimated and separated into specific and non-specific contributions. The molecular encapsulation of lomustine by β-cyclodextrin (β-CD) has been studied using fluorescence spectroscopy. The results are discussed in terms of the binding parameter and the effect of the solvent used. It was concluded that β-CD forms a 1:1 inclusional complex with lomustine in acetonitrile solution and its association constant was calculated to be 500 M(-1). In addition, and for the first time, a simple, rapid and high sensitive fluorimetric method for the determination of lomustine was developed based upon the enhancement effect produced through complex formation with β-CD. The new approach for the quantification of lomustine in the presence of β-CD was described in aqueous and organic solutions. Better limits of detection (0.31 µg ml(-1)) and quantification (1.05 µg ml(-1)) were obtained in aqueous solution with respect to those obtained in organic solvent.

Simultaneous determination of desloratadine and montelukast sodium using second-derivative synchronous fluorescence spectrometry enhanced by an organized medium with applications to tablets and human plasma

A rapid, simple, and sensitive second-derivative synchronous fluorimetric method has been developed and validated for the simultaneous analysis of a binary mixture of desloratadine (DSL) and montelukast sodium (MKT) in their co-formulated tablets. The method is based on measurement of the synchronous fluorescence intensities of the two drugs in McIlvaine's buffer, pH 2.3, in the presence of carboxy methyl cellulose sodium (CMC) as a fluorescence enhancer at a constant wavelength difference (Δλ) of 160 nm. The presence of CMC enhanced the synchronous fluorescence intensity of DSL by 216% and that of MKT by 28%. A linear dependence of the concentration on the amplitude of the second derivative synchronous fluorescence spectra was achieved over the ranges of 0.10-2.00 and 0.20-2.00 µg/mL with limits of detection of 0.02 and 0.03, and limits of quantification of 0.05 and 0.10 µg/mL for DSL and MKT, respectively. The proposed method was successfully applied for the determination of the studied compounds in laboratory-prepared mixtures and tablets. The results were in good agreement with those obtained with the comparison method. The high sensitivity attained by the proposed method allowed the determination of MKT in spiked human plasma with average % recovery of 100.11 ± 2.44 (n = 3).

Determination of montelukast sodium by capillary electrophoresis

This work verifies the potential of CE in the analysis of significant impurities of montelukast sodium - an active ingredient for the treatment of bronchial asthma. Using 20 mM borate buffer pH 9.2 with 10 mM SDS and 10 mM (2-hydroxypropyl)-gamma-CD (2HP-gamma-CD) it was possible to separate montelukast and several impurities, including its cis-isomer, after exposure to light and oxygen. The obtained method surpasses a chromatographic method for montelukast sodium in terms of time of analysis (9 min of CE analysis vs. 35 min HPLC) and efficiency (CE offered over 900 000 theoretical plates for montelukast). Good repeatability of the method was supported by the low % RSD for the migration time of montelukast (0.53%). For the first time, the capillary electrophoretic method was employed for temporal study of the degradation of montelukast. The results showed that degradation of montelukast and the formation of the cis-isomer mainly occurred during the first 2 days of exposure, and occurred to a higher degree when there was no contact with the air (oxygen) in the exposed sample.