Various solvent systems for solubility enhancement of enrofloxacin

Abstract

Solubility enhancement of antimicrobial drug enrofloxacin has been studied using a series of co-solvents and surfactants. Aqueous solubility of enrofloxacin could be increased up to 26 times. Co-solvents alone produced only small increase in solubility. However, the combined effect of co-solvents and buffer was synergistic and a large increase in solubility could be attained. Ionic surfactants were found to be much better solubilizing agents than non-ionic surfactant. Amongst ionic surfactants, solubility was found to be very high in anionic surfactant, sodium dodecylsulphate as compared to the cationic surfactant, cetyltrimethylammonium bromide. Up to 3.8 mg/ml of enrofloxacin could be dissolved in sodium dodecylsulphate. Mechanism of solubilization has been proposed and surfactant solubilization parameters have been calculated.

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“…transfer of drug from pure water to aqueous solution of solubilizers (Mixed solvents). [23,24] The value of Gibbs free energy for cosolvent and solid colvents was observed in range of -2490.16 to -6820.39 kJ mol −1 , respectively. Saturated solutions of drug were studied for pH dependent solubility at room temperature.…”

“…For various aqueous formulation blends of mixed solvents (AF1 to AF8) the value of ΔG 0 tr are extremely negatives and the value are observe to decrease as increase in solubilizers concentration, demonstrating spontaneous nature of drug solubilization. [23,24] The structures of drugs and hydrotropes with different centers of different electro negativity might responsible for the intermolecular hydrogen bonding and electrostatic attraction. Hydrogen bonding between the amide group of urea and various negative centers of drug molecule seems to impart aqueous solubility to aceclofenac.…”

“…The solubilizing power and the Gibbs free energy of transfer (ΔG 0 tr) of drug from pure water to the mixed solvent systems emphasize the solubilization effectiveness and thermodynamics involved during the solubility enhancement respectively. [23,24] Application of the mixed solvency has been employed in the present research work to develop the injection formulations of the model poorly water-soluble drug, aceclofenac. It may reduce the individual concentration of solubilizers and so reduce their toxicity associated with them.…”

“…V is the volume fraction of the co-solvent or mixed solvent and Φ is defined as the solubilization power of the cosolvent or mixed solvents. [22,23] The Gibbs free energy of transfer (ΔG 0 tr) of drug from pure water to aqueous solutions of excipients was calculated using the following equation…”

Electrochemical Studies of the Interaction of Clarithromycin with Bovine Serum Albumin

“…It has been shown that the distribution, free concentration and the metabolism of various drugs may be strongly affected by drugprotein interaction in the blood stream. [4][5][6][7] Therefore, study of the interactions between protein and drug molecules will help provide basic information on the pharmacological actions, biotransformation, bio-distribution, etc. of drugs.…”