The absorption and fluorescence spectra of sulfamethoxazole (SMO), sulfisoxazole (SFO), sulfathiazole (STO) and sulfanilamide (SAM) in different solvents, pH and I2-cyclodextrin (I2-CD) have been analyzed. The inclusion complexes of the above sulfa drugs with I2-CD were investigated by UV-visible spectroscopy, fluorometry, DFT, SEM, FT-IR and 1H NMR. The solvent study indicates that the position of the substituent (oxazole or thiazole group) in the SAM molecule (R-SO2-NH-group) is not the key factor to change the absorption and emission behavior of these sulpha drug molecules. In aqueous solution, a single fluorescence band (34 nm) was observed whereas in solutions of I2-CD dual emission (43 nm) was noticed in sulpha drug compounds. Formation of the inclusion complex in SMO, SFO and STO should result dual emission which is due to a Twisted Intramolecular Charge Transfer band (TICT). The I2-CD study indicates that (i) sulpha drugs form 1:1 inclusion complexes with I2-CD and (ii) the red shift and the presence of TICT in the I2-CD medium confirms heterocyclic ring encapsulated in the I2-CD cavity with the aniline ring present on the out side of the I2-CD cavity.
Related Content
Effect of Solvents and pH on β-Cyclodextrin Inclusion Complexation of 2,4-Dihydroxyazobenzene and 4-Hydroxyazobenzene
The spectral characteristics of 2,4-dihydroxyazobenzene (DHAB, sudan orange G) and 4-hydroxyazobenzene (HAB) have been studied in various solvents, different hydrogen ion and β-cyclodextrin (β-CD) concentrations, and are compared with azobenzene (AB). The inclusion complexes of the above molecu...


Carbon Nanotube: A Novel Carrier for Sustained Release Formulation
The present work describes the physicochemical interaction of multi-walled carbon nanotubes (MWCNTs) with drugs differing in physicochemical properties and shows the potential of MWCNTs in extended release dosage form design. The drug-nanotube adsorbate of candesartan cilexetil (CC), diclofenac s...
A Study on Host–Guest Complexation of 5-Amino-2-Mercaptobenzimidazole with β-Cyclodextrin
Spectral characteristics of 5-amino-2-mercaptobenzimidazole (AMBZ) have been investigated in aqueous β-cyclodextrin (β-CDx) solutions. The absorbance and fluorescence intensity of the neutral and monocationic forms of AMBZ are enhanced due to the formation of an inclusion complex with β-CDx. T...


Absorption and fluorescence spectral characteristics of norepinephrine, epinephrine, isoprenaline, methyl dopa, terbutaline and orciprenaline drugs
The absorption and fluorescence spectral characteristics of norepinephrine, epinephrine, isoprenaline, methyl dopa, orciprenaline and terbutaline have been investigated for levels of different pH and β-cyclodextrin (β-CD). The inclusion processes are discussed based on absorption, emission and ...
Detection of Fabric Defects by Auto-Regressive Spectral Analysis and Support Vector Data Description
For the purpose of realizing fast and effective detection of defects in woven fabric, and in consideration of the inherent characteristics of fabric texture, i.e., periodicity and orientation, a new approach for fabric texture analysis, based on the modern spectral analysis of a time series rathe...

The effect of solvent on the excited vibronic states and first hyperpolarizability of pushpull merocyanines
The absorption and fluorescence spectral properties of several merocyanines with very high first hyperpolarizabilities in fluid solutions are reported. These molecules contain a cyanodicyanomethylidenedihydrofuran electron acceptor group and with either a pyridinylidene or quinolinylidene electro...
Radiation modification of the uranium complexes in LiF crystals
Time-resolved pulse spectrometry method has been used to research uranium emission in LiF crystals. The spectral-kinetic parameters of uranium photoluminescence for LiF (U) crystals with intentional LiOH doping irradiated in a wide absorbed dose interval 5.11-1.16 Gy have been researched for the ...

Preparation and luminescent characteristics of Sr3RE2(BO3)4: Dy3+ (RE=Y; La; Gd) phosphors for white LED
Dysprosium-activated Sr3RE2(BO3)4 (RE=Y, La, Gd) phosphors were synthesized by a high temperature solid-state reaction method. The phase uniformity of the phosphors was characterized by X-ray powder diffraction (XRD) and the luminescence characteristics were investigated. The excitation spectra a...
Investigation of the factors determining the modulation characteristics of gas-discharge IR sources
The effect of design parameters and voltage of pulsed cesium sources with sapphire envelopes on their modulation characteristics are considered for the following combinations of operating parameters: the average repetition rate of current pulses up to fi = 1. kHz and the consumed electric power u...

Solvent Effects on the Structure-Property Relationship of Some Potentially Pharmacologically Active 3-(4-Substituted Benzyl)-5-Ethyl-5-Phenyl- and 3-(4-Substituted Benzyl)-5,5-Diphenylhydantoins
Two series of 3-(4-substituted benzyl)-5-ethyl-5-phenyl- and 3-(4-substituted benzyl)-5,5-diphenylhydantoins were synthesized and their UV absorption spectra were recorded in the region 2–4 nm in selected solvents of different polarity. The effects of solvent dipolarity/polarizability and solve...