Chitosan Loaded Mucoadhesive Microspheres of Gliclazide - Journal

Best results were obtained with p-toluyl sulphonic acid for Eisomer
of dothiepin (94%) while other acids also yielded more
than 84%.
CONCLUSION
The main focus of this research work was to understand the
effect of different acid catalysts on the formation of E- and Z-
isomers of Dothiepin and to characterize the isomers by
1 HNMR and HPLC methods. The yield of E-isomer of
dothiepin was achieved in the range of 89-94 %. From the
experiments conducted, use of p-toluyl sulphonic acid
(GKRA-13) yielded maximum of 94% E-isomer and was
found to be ideal reagent for the dehydration of the alcohol
[Compound-A] to form E- and Z- isomers of dothiepin.
Other acids namely L(+) tartaric acid, oxalic acid and maleic
acid led to the formation of E isomer in the range of 89-92%.
Quantification of E- and Z-isomers of dothiepin obtained by
NMR showed the range of 85:15 and 94:06 and HPLC was
found to be in the range of 89:11 and 94:6.
ACKNOWLEDGEMENT
The authors would like to thank Prof. B. G. Shivananda
Principal, Al-Ameen College of Pharmacy, Bangalore and
Mr Anjan K. Roy, Managing Director, R.L.Fine Chemicals,
Bangalore for providing support and necessary facilities,
Department of Inorganic and Physical Chemistry, Indian
Institute of Science, Bangalore, for providing help in
obtaining the various spectra.
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Gopal Krishna Rao et al./ Effect of Different Acids on the Formation of E and Z Isomers of Dothiepin
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Address for Correspondence
Gopal Krishna Rao, Department of Pharmaceutical Chemistry, Al-Ameen
College of Pharmacy, Bangalore, Karnataka, India
E-mail: gkfadnis@gmail.com
RJPS, Jul - Sep, 2011/ Vol 1/ Issue 2