1.A Validated LC Method for Determination of the Enantiomeric Purity of Montelukast
Sodium in Bulk Drug Samples and Pharmaceutical Dosage Forms
P. Radhakrishnanand, D. V. Subba Rao. Chromatographia 2008, 68, August (No. 3/4)
A few analytical methods had been reported in the literature for determination of montelukast sodium in human plasma by column-switching HPLC with fluorescence detection. Liu et al. separated the enantiomers of montelukast from human plasma by use of column-switching with fluorescence detection, but the injection procedure was a laborious and time-consuming process. As far as we are aware no enantioselective HPLC methods have been reported in the literature for determination of the enantiomeric purity of montelukast sodium or accurate quantification of the impurity, i.e. the S enantiomer, in bulk drugs and pharmaceutical formulations. This paper deals with the development and validation of a method for determination of the enantiomeric purity of montelukast sodium.
2.Novel montelukast sodium-loaded stable oral suspension bioequivalent to the commercial granules in rats
Dong Wuk Kim • Young Hun Kim • Abid Mehmood Yousaf. Arch. Pharm. Res. (2016) 39:539–546
Various stabilizers (62.4 mg) were added in 100 ml of the suspensions containing 312 mg montelukast sodium and 2496 mg Avicel (Fig. 2). As shown in Fig. 2a, the suspension without stabilizer was given approximately 1.8 % montelukast sulphoxide and demonstrated the sedimentation phenomenon at 2 months. The suspension with sodium pyrosulphate presented \1 % montelukast sulphoxide, but it induced sedimentation at 2 months. The suspensions with sodium thiosulfate and propyl gallate exhibited [1 % degradation product, and induced sedimentation at 2 months. Moreover, the suspension with fumaric acid resulted in \1 % degradation product and total impurities at 2 months; however, the sedimentation took place. Additionally, different quantities of fumaric acid (3.12–62.4 mg) were transferred to 100 ml of the montelukast sodium (312 mg)-loaded suspensions, and their stabilities were evaluated (Fig. 3). As the amounts of fumaric acid were increased, the concentrations of degradation product were reduced.
3.pKa Determinations for Montelukast Sodium and Levodropropizine
Ibrahim Narin, Salih Sarioglan, Beril Anilanmert, Hayati Sari. J Solution Chem (2010) 39: 1582–1588
Acid dissociation constant determination studies have been performed for drugs like epirubicin·HCl and irinotecan·HCl, cefetamet and many other drugs used as antiinflammatories, antibiotics, β-blockers, etc. Mixed solvents were used for some of these drug studies, because of solubility problems in water at the concentrations used in the experiments. In this study, the pKa constants of Montelukast sodium and Levodropropizine were determined potentiometrically using the Irving–Rossotti method. Relative abundances of the ionized and unionized species were calculated at various pHs.
4.Novel montelukast sodium-loaded clear oral solution prepared with hydroxypropyl-b-cyclodextrin as a solubilizer and stabilizer: enhanced stability and bioequivalence to commercial granules in rats
Young Hun Kim • Dong Wuk Kim • Min Seok Kwon. J Incl Phenom Macrocycl Chem (2015) 82:479–487
Various amounts of solubilizers, preservatives and EDTA sodium were completely dissolved in 100 ml distilled water. Soluplus, Kolliphor, PVP and HP-b-CD were used as solubilizers. Methylparaben sodium and propylparaben sodium were used as preservatives. Then, montelukast sodium was added into these solutions and stirred for 1 h, leading to the montelukast sodium-loaded oral solutions. The drug solubility and stability tests were carried out with these solutions as mentioned below.