Design and Synthesis of Lactose, Galactose and Cholic Acid Related Dual Conjugated Chitosan Derivatives as Potential Anti Liver Cancer Drug Carriers.

Cholic acid and galactose or lactose dual conjugated chitosan derivatives were designed and synthesized as potential anti liver cancer drug carriers, their structures were characterized through proton NMR spectra, elemental analysis, size distribution, zeta potential, and scanning electron microscope image studies. The ability of the dual conjugates to enhance the aqueous solubility of the cancer drug sorafenib was evaluated. The entrapment efficiency (EE%) and drug content (DC%) of sorafenib in the inclusion complexes were measured. The chitosan dual conjugate with cholic acid and galactose was found to be best in enhancing the aqueous solubility of sorafenib. The solubility of sorafenib in water has increased from 1.7 µg/mL to 1900 µg/mL which is equal to 1117-fold increase in its solubility due to the inclusion complex with chitosan conjugate.

Formation of inclusion complex of enrofloxacin with 2-hydroxypropyl-ß-cyclodextrin.

Enrofloxacin, a third-generation fluoroquinolone, is a broad-spectrum antimicrobial drug against a lot of veterinary bacterial diseases. However, bactericidal activity of enrofloxacin is concentration-dependent and its poor aqueous solubility and bitter taste limit its development and application. Meanwhile, 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD), a widely used cyclodextrin analog, is a safe and an effective drug carrier. It forms inclusion complexes with its drug substrates and improves their physiochemical and pharmacokinetic properties. Enrofloxacin was also found to form a stable inclusion complex with HP-ß-CD and different research groups have shown improved solubility for enrofloxacin by 32.5%, 9.25 and 165-fold. Our own efforts in this direction resulted in manifold improvement (916-fold) in its solubility compared to the previous studies. It was further shown that pharmaceutical properties, absorption and bioavailability, of enrofloxacin have also been significantly improved by complexation with HP-ß-CD.

Synthesis of carbohydrate conjugated 6A,6D-bifunctionalized ß cyclodextrin derivatives as potential liver cancer drug carriers.

Galactosyl and lactosyl conjugated 6A,6D-bifunctionlized ß cyclodextrin derivatives were designed and synthesized as the potential liver cancer drug carriers through SN2 replacement and click reactions in order to increase liver cancer drug's targeting ability, solubility and stability. The synthetic methods and strategies to obtain the designed compounds were discussed.

Efficient and practical synthesis of Fondaparinux.

Combining advantageous sequences of Alchemia and Sanofi methods of synthesis of Fondaparinux, a more efficient and practical synthetic strategy for the synthesis of corresponding protected pentasaccharide was developed. The protected pentasaccharide was smoothly converted into Fondaparinux in overall high yield (1%).