Effect of mechanochemical inclusion of triamterene into sulfobutylether-ß-cyclodextrin and its improved dissolution behavior.

The formation of inclusion complexes between triamterene (TT) and cyclodextrins (CDs) to increase the water apparent solubility of TT was investigated. UV data showed that the binding constant of the TT/sulfobutylether-ß-cyclodextrin (SBE-ß-CD) inclusion complex was 510 L/mol. The phenyl ring of TT was inserted into the secondary hydroxy face of SBE-ß-CD, as demonstrated by 1H-1H rotating frame nuclear Overhauser effect spectroscopy NMR. Physicochemical properties of solid TT/SBE-ß-CD complexes prepared by physical mixing, kneading, freeze-drying, and mechanochemical methods were studied by X-ray diffraction and 13C cross-polarization and magic angle spinning NMR. With the mechanochemical method, the diffraction peak corresponding to TT disappeared, indicating the formation of an inclusion complex. The results of the dissolution test revealed that the solid complex obtained by the mechanochemical method improved the dissolution of TT. The water apparent solubility of TT can be improved by simple mechanical mixing without organic solvents, and improved bioavailability after oral administration is expected.

Inclusion complexes of trihexyphenidyl with natural and modified cyclodextrins.

The solubility of trihexyphenidyl (Thp) was improved by its combination with ß-cyclodextrin (ß-CD) and modified ß-CDs. The solubility of Thp was found to be increased in the presence of ß-CD, hydroxypropyl-ß-cyclodextrin (HP-ß-CD), methyl-ß-cyclodextrin (Me-ß-CD) and sulfobutylether-ß-cyclodextrin (SBE-ß-CD). In particular, the solubility of Thp in conjunction with SBE-ß-CD was increased by a factor of 11. The formation constant (K c ) for the Thp/SBE-ß-CD inclusion complex was determined to be 2300 L/mol based on fluorometry data. The structure of the Thp/SBE-ß-CD complex in aqueous solution was examined by (1)H-(1)H rotating frame nuclear Overhauser effect spectroscopy (ROESY) NMR, and the phenyl moiety of the Thp was found to coordinate with the secondary hydroxyl face of the SBE-ß-CD. A solid Thp/SBE-ß-CD inclusion complex was prepared by freeze-drying.

Effect of 18ß-glycyrrhetinic acid and hydroxypropyl γcyclodextrin complex on indomethacin-induced small intestinal injury in mice.

Non-steroidal anti-inflammatory drugs (NSAIDs)-induced small intestinal injury is a serious clinical event with recent advances of diagnostic technologies, but a successful therapeutic method to treat such injuries is still lacking. Licorice, a traditional herbal medicine, and its derivatives have been widely used for the treatment of a variety of diseases due to their extensive biological actions. However, it is unknown whether these derivatives have an effect on NSAIDs-induced small intestinal damage. Previously, the anti-inflammatory effects of three compounds extracted from the licorice root, glycyrrhizin, 18ß-glycyrrhetinic acid, and dipotassium glycyrrhizinate, were compared in vitro cell culture. The most prominent inhibitory effect on the tumor necrosis factor-α (TNF-α) production was observed with the administration of 18ß-glycyrrhetinic acid as an active metabolite of glycyrrhizin. In this study, a complex compound of 18ß-glycyrrhetinic acid and hydroxypropyl γcyclodextrin was examined to improve the oral bioavailability. After administration of this complex to indomethacin treated mice, a significantly high plasma concentration of 18ß-glycyrrhetinic acid was detected using the tandem mass spectrometry coupled with the HPLC. Furthermore, the complex form of 18ß-glycyrrhetinic acid and hydroxypropyl γcyclodextrin reduced mRNA expressions of TNF-α, interleukin (IL)-1ß, and IL-6, which was histologically confirmed in the improvement of indomethacin-induced small intestinal damage. These results suggest that the complex of 18ß-glycyrrhetinic acid and hydroxypropyl γcyclodextrin has the potential therapeutic value for preventing the adverse effects of indomethacin-induced small intestinal injury.

Phosphorylation of 5'-deoxy-5-fluorouridine with inorganic phosphorylating agents.

The phosphorylation of 5'-deoxy-5-fluorouridine (doxifluridine, 5'-DFUR) has been achieved using inorganic cyclo-triphosphate (P(3m), Na(3)P(3)O(9)) and monoimido-cyclo-triphosphate (MCTP, Na(3)P(3)O(8)NH) in aqueous solution. In the reaction of 5'-DFUR with P(3m), 2'-monophospho-5'-DFUR and 3'-monophospho-5'-DFUR were synthesized with a total yield of more than 95%. In the reaction of 5'-DFUR with MCTP, 2'-diphosphoramidophosphono-5'-DFUR and 3'-diphosphoramidophosphono-5'-DFUR were synthesized with a total yield of more than 40%. The phosphorylated products with P(3m) and MCTP were stable in neutral and alkaline solutions.

Phosphorylation of nucleosides and nucleotides with inorganic monoimido-cyclo-triphosphate.

The phosphorylation of nucleosides (adenosine, guanosine, cytidine, and uridine) and nucleotides (adenosine 5'-monophosphate, guanosine 5'-monophosphate, cytidine 5'-monophosphate and uridine 5'-monophosphate) has been achieved using inorganic monoimido-cyclo-triphosphate (MCTP, Na(3)P(3)O(8)NH) in aqueous solution. In this reaction, the 2'-OH or 3'-OH group of the beta-D-ribofuranose unit was phosphorylated and the total yield was more than 30% and 14%, respectively. The main products were 2'-diphosphoramidophosphononucleoside and 2'-diphosphoramidophosphononucleoside 5'-monophosphate.

Evaluation of the in vitro pyrogen test system based on proinflammatory cytokine release from human monocytes: comparison with a human whole blood culture test system and with the rabbit pyrogen test.

The reliability of an in vitro pyrogen test system based on proinflammatory cytokine release from human monocytic cells was assessed by comparison with a test system based on a human whole blood culture as well as with the conventional rabbit pyrogen test. The human cells used as the pyrogen indicator cells were newly selected by subcloning of a human monocytic cell line, Mono-Mac-6. The selected cells, named MM6-CA8, responded to various pyrogens, including endotoxin, peptidoglycan (PG), Staphylococcus aureus Cowan 1 (SAC), and poly(I x C), with a high sensitivity and produced proinflammatory cytokines, such as interleukin 1 (IL-1), IL-6, and tumor necrosis factor alpha. Among these cytokines, IL-6 was produced most sensitively in response to traces of the pyrogens and detected in the largest quantities in the culture medium. The cytokine-producing responses of MM6-CA8 cells correlated significantly with the responses of cultured human whole blood, which represents an ex vivo culture test system reproducing pyrogen-induced cytokine production in the human body. In terms of cytokine inducibility, the pyrogens were ranked in the order endotoxin > PG > poly (I. C) > SAC in both culture systems, a ranking which almost agreed with the ranking of their pyrogenicity as assessed by the rabbit pyrogen test. These results suggest that the in vitro responsiveness of MM6-CA8 cells to various pyrogens is highly relevant for human pyrogenic reactions. Therefore, the in vitro test system is useful and reliable for detecting the presence of materials that are pyrogenic for humans.