Release characteristics in vitro and pharmacokinetics of chitosan coated curcumin liposomes in rats / 中国药理学通报

Aim To investigate the in vitro release be-havior of chitosan coated curcumin liposomes ( CMLP-CS ) and its pharmacokinetic characteristics in rats. Methods The cumulative release rate of CMLP-CS in pH 1. 2 hydrochloric acid solution and pH 6. 8 phos-phate buffer solution was investigated by dynamic dial-ysis method. The in vitro release curve was drawn. The release behavior was evaluated by similarity factor method. The drug concentration in blood was deter-mined by high performance liquid chromatography ( HPLC) . The pharmacokinetic data were analyzed by DAS 2.1.1 software. Results The cumulative release rate of CMLP-CS in pH 1. 2 hydrochloric acid solution and pH 6. 8 phosphate buffer solution was ( 70.48 ±0.50)％, (72.35 ± 1.04)％, respectively, and CM-LP-CS release in two release media was similar. AUC (0～72 h) , MRT (0～72 h) and Cmax were calculated to be 8.9, 3.7 and 1. 5 times of free curcumin, re-spectively. The relative bioavailability of CMLP-CS was 846. 5％. Conclusion CMLP-CS can improve the in vitro release behavior and significantly enhance the fraction of bioavailability of curcumin in rats.

In vitro release and in situ gastrointestinal absorption of evodiamine butyryl derivative-loaded solid lipid nanoparticles / 中国药理学通报

Aim To prepare evodiamine butyryl deriva-tive (EBD) and evodiamine butyryl derivative-loaded solid lipid nanoparticles (EBDLN), and study its re-lease in vitro,and to investigate its in situ gastrointesti-nal absorption. Methods EBD was prepared by a one-step synthetized method, and then EBDLN was prepared by a film dispersion method. Dynamic dialy-sis was used to evaluate drug release in vitro,and sin-gle-pass gastrointestinal perfusion was employed to study the gastrointestinal absorption of EDM,EBD and EBDLN. Results In identical release media, there were identical drug release tendencies of EBD and EB-DLN, but the release rate of EBDLN was faster than EBD. Compared with EDM and EBD, the Kavalues and Pappvalues of EBDLN in every perfusion segment increased significantly. The Kaof EBDLN in stomach, duodenum, jejunum, ileum and colon was 110.14-fold,56.70-fold,51.23-fold,45.70-fold and 127.23-fold of free EDM respectively. The Pappvalue of EB-DLN was 9.74-fold, 4.48-fold, 3.82-fold and 11.3-fold of that of free EDM. Conclusion EBDLN has sustained effect and can enhance the gastrointestinal absorption of EDM and EBD.

A preliminary study of pharmacokinetics of evodiamine hydroxypropyl-β-cyclodextrin inclusion complex / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the pharmacokinetic parameters of evodiamine hydroxypropyl-β-cyclodextrin inclusion complex and free evodiamine suspension in rats, and investigate the pharmacokinetic characteristics of evodiamine inclusion complex.</p><p><b>METHODS</b>Both water solubility and cumulative release percentage of EHD were tested with evodiamine as the control. Blood samples were collected from the venous plexus of SD rats after intravenous administration with evodiamine inclusion complex and free evodiamine at 100 mg/kg (equivalent evodiamine dose). Plasma concentrations of evodiamine were determined by high-performance liquid chromatography (HPLC), and the pharmacokinetic parameters were calculated using DAS 2.1.1.</p><p><b>RESULTS</b>The evodiamine inclusion complex showed a better water solubility (18.46±0.36 µg/mL) and a higher cumulative release percentage [(76.8±4.9)%] than free evodiamine. The pharmacokinetic parameters of evodiamine inclusion complex and free evodiamine in rats were as follows: Cmax, 252.5±12.43 vs 161.3±3.45 µg/L; T(max), 4.00±0 vs 4.07±0 h; MRT(0-∞), 8.46±0.91 vs 4.43±0.74 h; AUC(0-t), 2266.40±28.64 vs 911.92±8.53 µg·L(-1)·h(-1); AUC(0-∞), 2359.76±31.58 vs 919.16±9.73 µg·L(-1)·h(-1). The relative bioavailability of evodiamine inclusion complex was 256.73%.</p><p><b>CONCLUSION</b>Compared with free evodiamine, evodiamine inclusion complex has a higher bioavailability.</p>

Bioequivalence of pyridostigmine bromide dispersible tablets in rabbits / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the pharmacokinetic parameters of pyridostigmine bromide dispersible tablets and common tablets in rabbits.</p><p><b>METHODS</b>Twelve rabbits were given an oral dose (60 mg) of pyridostigmine bromide dispersible tablets or common tablets in a randomized crossover study. The plasma concentration of pyridostigmine bromide was determined by reversed-phase ion pair chromatography. The pharmacokinetic parameters were calculated using DAS2.1.1 software.</p><p><b>RESULTS</b>The pharmacokinetic parameters showed no significant differences in rabbit plasma between pyridostigmine bromide dispersible tablets and common tablets. The two tablets had a C(max) of 1.83∓0.08 mg·L(-1) and 1.68∓0.03 mg·L(-1), tmax of 2.33∓0.41 h and 2.58∓0.20 h, AUC(0-24) of 15.50∓0.62 mg·h·L(-1) and 15.14∓0.30 mg·h·L(-1), AUC(0-∞) of 15.82∓0.70 mg·h·L(-1) and 15.57∓0.32 mg·h·L(-1), respectively. The relative bioavailability F(0-24) was 102.38% and F(0-∞) was 101.61% for the dispersible tablets.</p><p><b>CONCLUSION</b>The two tablets are bioequivalent in rabbits.</p>

Pharmacokinetic study of a new chewing gum dextromethorphan delivery system / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish an high-performance liquid chromatography (HPLC)-based method for analysis of the pharmacokinetics and relative bioavailability of dextromethorphan chewing gum tablets in rabbits.</p><p><b>METHODS</b>The pharmacokinetic parameters and the relative bioavailability of dextromethorphan chewing gum preparation in rabbits were compared with those of the commercially available chewing dextromethorphan tablets using 3P97 software.</p><p><b>RESULTS</b>Pharmacokinetic analysis of the new dextromethorphan chewing gum tablets showed a AUC of 488.76 ∓ 175.00 ng.ml(-1).h, C(max) of 95.45 ∓ 17.53 ng/ml, and t(max) of 1.83 ∓ 0.57 h as compared with the corresponding parameters of 370.13 ∓ 90.56 ng.ml(-1).h, 174.00 ∓ 47.88 ng.ml, and 1.04 ∓ 0.14 h for the commercially available chewing tablets. The relative bioavailability of the new chewing gum medicine system was (140.73 ∓ 65.91)%.</p><p><b>CONCLUSION</b>The new dextromethorphan chewing gum preparation shows an increased AUC((0→)), decreased C(max), and prolonged t(max) in comparison with the commercially available chewing tablets, with also a greatly enhanced relative bioavailability.</p>