title: Enhancement of dissolution rate and bioavailability of aceclofenac: a chitosan-based solvent change approach.
abstract: In this study the significant effect of chitosan on improving the dissolution rate and bioavailability of aceclofenac has been demonstrated by simple solvent change method. Chitosan was precipitated on aceclofenac crystals using sodium citrate as the salting out agent. The pure drug and the prepared co-crystals with different concentrations of chitosan (0.05-0.6%) were characterized in terms of solubility, drug content, particle size, thermal behaviour (differential scanning calorimetry, DSC), X-ray diffraction (XRD), morphology (scanning electron microscopy, SEM), in vitro drug release and stability studies. The in vivo performance was assessed by preclinical pharmacodynamic (analgesic and anti-inflammatory activity) and pharmacokinetic studies. The particle size of the prepared co-crystals was drastically reduced during the formulation process. The DSC showed a decrease in the melting enthalpy indicating disorder in the crystalline content. The XRD also revealed a characteristic decrease in crystallinity. The dissolution studies demonstrated a marked increase in the dissolution rate in comparison with pure drug. The considerable improvement in the dissolution rate of aceclofenac from optimized crystal formulation was attributed to the wetting effect of chitosan, decreased drug crystallinity, altered surface morphology and micronization. The optimized co-crystals exhibited excellent stability on storage at accelerated conditions. The in vivo studies revealed that the optimized crystal formulation provided a rapid pharmacological response in mice and rats besides exhibiting improved pharmacokinetic parameters in rats.
authors.affiliation: Manipal College of Pharmaceutical Sciences, Manipal University, Manipal 576104, Karnataka, India. ssmutalik@yahoo.com
authors.forename: Srinivas
authors.initials: S
authors.lastname: Mutalik
authors.forename: Parambil
authors.initials: P
authors.lastname: Anju
authors.forename: Krishnan
authors.initials: K
authors.lastname: Manoj
authors.forename: Achutha Nayak
authors.initials: AN
authors.lastname: Usha
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage*; D001682:Biological Availability; D002152:Calorimetry, Differential Scanning; D048271:Chitosan / Q000008:administration & dosage*; D004008:Diclofenac / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D008297:Male; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D051381:Rats; D017208:Rats, Wistar; D012995:Solubility; D012997:Solvents; D014961:X-Ray Diffraction
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D012997:Solvents; D004008:Diclofenac; D048271:Chitosan; C056498:aceclofenac