Sustained release of flufenamic acid from a drug-triacetyl-beta-cyclodextrin complex.
Triacetyl-beta-cyclodextrin (TA-beta-CyD), a hydrophobic cyclodextrin derivative that is insoluble in water, was used to form a complex with flufenamic acid (FA). Complexes of FA with TA-beta-CyD (FA-TA-beta-CyD) at various molar ratios (1:1, 1:2, 1:3) were prepared by a kneading method, using ethanol as a solvent. FA-TA-beta-CyD complex formation was demonstrated by differential scanning calorimetry and powder X-ray diffractometry. The release rate of FA from the FA-TA-beta-CyD complexes was measured in both the Japanese Pharmacopoeia XII 1st fluid pH 1.2 and isotonic phosphate buffer pH 6.8. The release rate of FA from the FA-TA-beta-CyD complexes in the isotonic phosphate buffer pH 6.8 was significantly retarded compared to the release rate of FA from the FA-glucose mixture. After 1 h, 100% of the drug was released from the FA-glucose mixture and 10-25% was released from the complexes. When either the powder of the FA-glucose mixture or the FA-TA-beta-CyD mixture was administered directly into the intraduodenal lumen in rats, the plasma concentration of FA reached a maximum level within 40 min after administration. On the other hand, when the FA-TA-beta-CyD complexes were administered into the intraduodenal lumen, the plasma concentration of FA did not show a sharp peak, but remained at a plateau level (10-18 microg/ml) for 6-8 h. An increased mean residence time of FA following FA-TA-beta-CyD complexes administration was observed; however, the AUC(0-10) for the FA-TA-beta-CyD complexes showed no significant difference from that for the FA-TA-beta-CyD mixture. These results indicate that TA-beta-CyD may serve as a hydrophobic carrier in sustained-release preparations of FA. The drug-TA-beta-CyD complexes may therefore be useful in oral administration to achieve prolonged action and reduced side effects.
Nakanishi
K
K
Faculty of Pharmaceutical Sciences, Setsunan University, Nagaotoge-cho, Hirakata, Osaka, Japan.
Masukawa
T
T
Nadai
T
T
Yoshii
K
K
Okada
S
S
Miyajima
K
K
D000042:Absorption; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage*; D003505:Cyclodextrins / Q000008:administration & dosage*; D003692:Delayed-Action Preparations; D005439:Flufenamic Acid / Q000008:administration & dosage* / Q000493:pharmacokinetics; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D047392:beta-Cyclodextrins
D000894:Anti-Inflammatory Agents, Non-Steroidal; D003505:Cyclodextrins; D003692:Delayed-Action Preparations; D047392:beta-Cyclodextrins; D005439:Flufenamic Acid; C031215:betadex