title: Evaporation Behavior and Characterization of Eutectic Solvent and Ibuprofen Eutectic Solution.
abstract: Liquid eutectic system of menthol and camphor has been reported as solvent and co-solvent for some drug delivery systems. However, surprisingly, the phase diagram of menthol-camphor eutectic has not been reported previously. The evaporation behavior, physicochemical, and thermal properties of this liquid eutectic and ibuprofen eutectic solution were characterized in this study. Differential scanning calorimetry (DSC) analysis indicated that a eutectic point of this system was near to 1:1 menthol/camphor and its eutectic temperature was -1°C. The solubility of ibuprofen in this eutectic was 282.11 ± 6.67 mg mL(-1) and increased the drug aqueous solubility fourfold. The shift of wave number from Fourier transform infrared spectroscopy (FTIR) indicated the hydrogen bonding of each compound in eutectic mixture. The weight loss from thermogravimetric analysis of menthol and camphor related to the evaporation and sublimation, respectively. Menthol demonstrated a lower apparent sublimation rate than camphor, and the evaporation rate of eutectic solvent was lower than the sublimation rate of camphor but higher than the evaporation of menthol. The evaporation rate of the ibuprofen eutectic solution was lower than that of the eutectic solvent because ibuprofen did not sublimate. This eutectic solvent prolonged the ibuprofen release with diffusion control. Thus, the beneficial information for thermal behavior and related properties of eutectic solvent comprising menthol-camphor and ibuprofen eutectic solution was attained successfully. The rather low evaporation of eutectic mixture will be beneficial for investigation and tracking the mechanism of transformation from nanoemulsion into nanosuspension in the further study using eutectic as oil phase.
authors.affiliation: Department of Pharmaceutical Technology, Faculty of Pharmacy, Silpakorn University, Nakorn Pathom, 73000, Thailand. tphaechamud011@yahoo.com.
authors.forename: Thawatchai
authors.initials: T
authors.lastname: Phaechamud
authors.affiliation: Pharmaceutical Intelligence Unit Prachote Plengwittaya, Faculty of Pharmacy, Silpakorn University, Nakorn Pathom, 73000, Thailand.
authors.forename: Sarun
authors.initials: S
authors.lastname: Tuntarawongsa
authors.affiliation: Department of Biopharmacy, Faculty of Pharmacy, Silpakorn University, Nakorn Pathom, 73000, Thailand.
authors.forename: Purin
authors.initials: P
authors.lastname: Charoensuksai
mesh_terms: D002152:Calorimetry, Differential Scanning / Q000379:methods; D002164:Camphor / Q000737:chemistry; D016503:Drug Delivery Systems / Q000379:methods; D006860:Hydrogen Bonding; D007052:Ibuprofen / Q000737:chemistry*; D008610:Menthol / Q000737:chemistry; D019999:Pharmaceutical Solutions / Q000737:chemistry*; D012995:Solubility; D012997:Solvents / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013696:Temperature
chemical_list: D019999:Pharmaceutical Solutions; D012997:Solvents; D008610:Menthol; D002164:Camphor; D007052:Ibuprofen
keywords: camphor; eutectic solvent; evaporation behavior; ibuprofen; menthol; phase diagram