ABSTRACT
Arundic acid, (R)-(-)-2-propyloctanonic acid, is a novel neurological agent for intractable neurodegenerative diseases. However, arundic acid, an oily drug, has low aqueous solubility and severe bitter/irritating tastes. Consequently, these physicochemical properties of arundic acid need to be improved to develop its pharmaceutical preparations. In the present study, we evaluated whether parent cyclodextrins (CyDs) and 2-hydroxypropylated CyDs (HP-CyDs) can interact with arundic acid, and have powderization, solubilization and taste-masking properties. Of various CyDs, HP-ß-CyD had the most potent solubilizing effect for arundic acid. UV and (1)H NMR spectroscopic studies demonstrated that arundic acid formed inclusion complexes with CyDs at a molar ratio of 1:1 in solution. The complexation with CyDs changed an oily form of arundic acid to a solid form. The gustatory sensation studies indicate that of various CyDs, HP-ß-CyD and γ-CyD showed the most significant taste-masking effects in solution and powders, respectively. HP-ß-CyD significantly reduced the response of the electric potential caused by the adsorption of arundic acid to the taste sensor. These results suggest that hydrophilic CyDs have potential as multifunctional excipients for preparing solutions and powders containing arundic acid.
Subject(s)
Caprylates/chemistry , Drug Delivery Systems , Nootropic Agents/chemistry , beta-Cyclodextrins/chemistry , gamma-Cyclodextrins/chemistry , Caprylates/pharmacology , Chemical Phenomena/drug effects , Drug Compounding , Excipients/chemistry , Humans , Hydrophobic and Hydrophilic Interactions , Nootropic Agents/pharmacology , Powders/chemistry , Solubility , Solutions/chemistry , Taste/drug effects , Taste Perception/drug effectsABSTRACT
Plasma concentration profiles of arundic acid ((R)-(-)-2-propyloctanoic acid), an oil-like medicine, administered as soft-gel capsules in human clinical tests were predicted from the dissolution test data of the soft-gel capsules with different storage terms (short- and long-term stored drugs) by applying the in vitro-in vivo correlation (IVIVC). We established two linear-regression IVIVCs, which were characterized by either the in vitro dissolution behaviors against the pH 8.0 dissolution medium or the pH 6.8 dissolution medium containing 2% sodium dodecyl sulfate (SDS), in this study. Also, the prediction accuracies for the in vivo plasma profiles in humans for these two IVIVCs were compared. Regarding dissolution from the long-term stored capsule in pH 8.0 dissolution medium without surfactant, the prediction accuracies of the in vivo plasma profiles in humans were not satisfactory for the obtained IVIVC. The use of pH 6.8 dissolution medium containing 2% SDS, according to the Japanese guideline, improved the dissolution of the long-term stored capsule. Furthermore, the prediction accuracies for the in vivo plasma profiles in humans for these two IVIVCs were compared. The IVIVC established by the in vitro dissolution data obtained with the dissolution medium containing surfactant more effectively predicted the plasma drug concentration profiles following oral administrations of the soft-gel capsules under both storage conditions.
Subject(s)
Caprylates/blood , Caprylates/pharmacokinetics , Models, Biological , Administration, Oral , Buffers , Caprylates/administration & dosage , Capsules , Clinical Trials as Topic , Computer Simulation , Drug Stability , Gels , Humans , Hydrogen-Ion Concentration , In Vitro Techniques , Infusions, Intravenous , Injections, Intravenous , Intestinal Absorption/physiology , Linear Models , Predictive Value of Tests , Sodium Dodecyl Sulfate/chemistry , Solubility , Surface-Active Agents/chemistryABSTRACT
In this study, we examined the identification of fungi based on the sequence homology of the internal transcribed spacer 1 (ITS1) region. A newly designed primer pair could amplify the target region of all 42 strains tested. The PCR products were sequenced and the sequence homologies were searched by BLAST. It was demonstrated that this method is a reliable identification method at the genus or species level. At present, available databases are still insufficient to identify some fungi, but with the accumulation of further data in the ITS1 database, this method will be available for the identification of fungi.
