title: Probing location of anti-TB drugs loaded in Brij 96 microemulsions using thermoanalytical and photophysical approach.
abstract: The aim of this work is to monitor the changes in microstructure in nonionic Brij 96 microemulsions and to locate the solubilization loci of antituberculosis drugs (of variable solubility using photophysical and thermoanalytical properties. Using properties such as spectral shift, Stroke's shift, and anisotropy for two dyes, that is, Nile red (NR) and tris(2,2'-bipyridine)ruthenium(II) dichloride (RC), the structure of microemulsions has been investigated. With the help of spectral and deconvoluted analysis, it has been seen that rifampicin (RIF) shows a strong interaction with NR and isoniazid (INH) and pyrazinamide (PZA) with RC. It has been concluded that RIF molecules are mainly present at the interface toward oil side and INH toward hydrophilic side, whereas PZA remains in free water. The findings have been correlated with aqueous solubility drugs and partition coefficients. Differential scanning calorimetry elucidates the state of water in microheterogeneous environment and variation of different states, that is, free, bound, interphasal, and nonfreezable water with dilution. In addition, it confirmed the stability and location of the drugs in the prepared Brij 96 microemulsion formulations. A good agreement between both the studies has been achieved. These findings will help in elucidating the drug delivery properties of anti-TB drugs-loaded microemulsion formulations in future.
authors.affiliation: Dr. S. S. Bhatnagar University Institute of Chemical and Engineering Technology, Panjab University, Chandigarh, 160014, India.
authors.forename: Gurpreet
authors.initials: G
authors.lastname: Kaur
authors.forename: Surinder K
authors.initials: SK
authors.lastname: Mehta
mesh_terms: D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives / Q000737:chemistry; D000995:Antitubercular Agents / Q000032:analysis / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D056831:Coordination Complexes; D004337:Drug Carriers / Q000032:analysis / Q000737:chemistry*; D004339:Drug Compounding; D004355:Drug Stability; D004655:Emulsions; D005454:Fluorescence Polarization; D005456:Fluorescent Dyes / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D007538:Isoniazid / Q000032:analysis / Q000737:chemistry*; D008956:Models, Chemical; D010078:Oxazines / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011718:Pyrazinamide / Q000032:analysis / Q000737:chemistry*; D012293:Rifampin / Q000032:analysis / Q000737:chemistry*; D012995:Solubility; D013050:Spectrometry, Fluorescence; D014867:Water / Q000032:analysis; D017975:Ruthenium Compounds
chemical_list: D015082:2,2'-Dipyridyl; D000995:Antitubercular Agents; D056831:Coordination Complexes; D004337:Drug Carriers; D004655:Emulsions; D005456:Fluorescent Dyes; D007538:Isoniazid; D010078:Oxazines; D010938:Plant Oils; D011092:Polyethylene Glycols; D011718:Pyrazinamide; D012293:Rifampin; D014867:Water; C547232:tris(2,2-bipyridine)-ruthenium(II); D017975:Ruthenium Compounds; C033084:polyethylene glycol oleyl ether; C044808:nile red
keywords: Brij 96; Calorimetry (DSC); Fluorescence spectroscopy; Microemulsions; Nile red; Preformulation; UV/Vis Spectroscopy; isoniazid; pyrazinamide; rifampicin