This study pharmacokinetically examined the lovastatin sustained-release tablet and sustained-release capsule in Beagle dogs. An reversed-phase HPLC method was established for the determination of lovastatin in Beagl...This study pharmacokinetically examined the lovastatin sustained-release tablet and sustained-release capsule in Beagle dogs. An reversed-phase HPLC method was established for the determination of lovastatin in Beagle dog plasma. Pharmacokinetic findings were compared among three preparation(lovastatin sustained-release tablet,T p; sustained-release capsule,T J and conventional capsule). Our results showed that the pharmacokinetic parameters in 6 dogs after single-dose oral administration of three perparations were calculated. T max, C max and MRT revealed significant difference (P<0.05). Relative bioavailability was 111.5±16.9 % (T P) and 110.4%±9.6 % (T J). The pharmacokinetic parameters in the 6 dogs after multiple-dose oral administration of three perparations, T max, C max MRT and DF had significant difference (P<0.05); C av , C min and AUC 0-24 h displayed no significant difference (P>0.05). It is concluded that the lovastatin sustained-release tablet and sustained-release capsule are able to maintain a sustained-release for 24 h.展开更多
AIM: To investigate the interactions at a metabolic level between lovastatin, amiodarone and carbon tetrachloride in isolated rat hepatocytes. METHODS: For cell isolation two-step collagenase liver perfusion was perfo...AIM: To investigate the interactions at a metabolic level between lovastatin, amiodarone and carbon tetrachloride in isolated rat hepatocytes. METHODS: For cell isolation two-step collagenase liver perfusion was performed. Lovastatin was administered alone in increasing concentrations (1μmol/L, 3μmol/L, 5μmol/L and 10μmol/L) and in combination with CCl4 (86μmol/L). The cells were also pretreated with 14μmol/L amiodarone and then the other two compounds were added. RESULTS: Lovastatin promoted concentration-dependent significant toxicity estimated by decrease in cell viability and GSH level by 45% and 84%, respectively. LDHactivity increased by 114% and TBARS content by 90%. CCl4 induced the expected severe damage on the examined parameters. CCU induced toxicity was attenuated after lovastatin pretreatment, which was expressed in less increased values of LDH activity and TBARS levels, as well as in less decreased cell viability and GSH concentrations. However, the pretreatment of hepatocytes with amiodarone abolished the protective effect of lovastatin. CONCLUSION: We suggest that the observed cytopro-tective effect was due to interactions between lovastatin, CCl4 and amiodarone at a metabolic level.展开更多
The aim of present study was to formulate and evaluate a self-microemulsifying drug delivery systems(SMEDDS)containing lovastatin and to further explore the ability of porous Neusilin■ US2 tablet as a solid carrier f...The aim of present study was to formulate and evaluate a self-microemulsifying drug delivery systems(SMEDDS)containing lovastatin and to further explore the ability of porous Neusilin■ US2 tablet as a solid carrier for SMEDDS.SMEDDS formulations of varying proportions of peceol,cremophor RH 40 and transcutol-P were selected and subjected to invitro evaluation,including dispersibility studies,droplet size,zeta potential measurement and release studies.The results indicated that the drug release profile of lovastatin from SMEDDS formulations was statistically significantly higher(p-value<0.05)than the plain lovastatin powder.Thermodynamic stability studies also confirmed the stability of the prepared SMEDDS formulations.The optimized formulation,which consists of 12% of peceol,44% of cremophor RH 40,and 44% of transcutol-P was loaded into directly compressed liquid loadable tablet of Neusilin■ US2 by simple adsorption method.In order to determine the ability of Neusilin®US2 as a suitable carrier pharmacodynamics study were also carried out in healthy diet induced hyperlipidemic rabbits.Animals were administered with both liquid SMEDDS and solid SMEDDS as well.From the results obtained,Neusilin■ was found to be a suitable carrier for SMEDDS and was equally effective in reducing the elevated lipid profile.In conclusion,liquid loadable tablet(LLT)is predicted to be a promising technique to deliver a liquid formulation in solid state.展开更多
Two sets of CCD photometric observations for contact binary TU Boo were obtained in 2020 and 2021.Different from its asymmetric light curves published from the literature,our BVRcIc-band curves show that the heights o...Two sets of CCD photometric observations for contact binary TU Boo were obtained in 2020 and 2021.Different from its asymmetric light curves published from the literature,our BVRcIc-band curves show that the heights of maximum are almost equal.These distortions of light curves possibly indicate that the components were active in past 25 yr,but they were stable in the last two years.For total-eclipse binary TU Boo,due to some star-spots on the surface of the components,the physical structure obtained by many investigators are different.Therefore,the symmetric multi-color light curves in 2020,2021 are important for understanding configuration and evolution of this system.By using the Wilson–Devinney program,it is confirmed that TU Boo is an A-type shallow-contact binary with the temperature difference ofΔT=152 K and fill-out of f=14.67%.In the O−C diagram of orbital period analysis,a cyclic oscillation superimposed on a continuous decrease was determined.The long-term decreasing is often explained by the mass transfer from the more massive star to less massive one,this system will evolve into a deeper contact binary with time.The cyclic oscillations computed from much more CCD times of light minimum maybe result from the light-travel time effect via the presence of a third body.These characters of structure,evolution and ternary belong to typical A-type W UMa binaries with spectral G.展开更多
文摘This study pharmacokinetically examined the lovastatin sustained-release tablet and sustained-release capsule in Beagle dogs. An reversed-phase HPLC method was established for the determination of lovastatin in Beagle dog plasma. Pharmacokinetic findings were compared among three preparation(lovastatin sustained-release tablet,T p; sustained-release capsule,T J and conventional capsule). Our results showed that the pharmacokinetic parameters in 6 dogs after single-dose oral administration of three perparations were calculated. T max, C max and MRT revealed significant difference (P<0.05). Relative bioavailability was 111.5±16.9 % (T P) and 110.4%±9.6 % (T J). The pharmacokinetic parameters in the 6 dogs after multiple-dose oral administration of three perparations, T max, C max MRT and DF had significant difference (P<0.05); C av , C min and AUC 0-24 h displayed no significant difference (P>0.05). It is concluded that the lovastatin sustained-release tablet and sustained-release capsule are able to maintain a sustained-release for 24 h.
文摘AIM: To investigate the interactions at a metabolic level between lovastatin, amiodarone and carbon tetrachloride in isolated rat hepatocytes. METHODS: For cell isolation two-step collagenase liver perfusion was performed. Lovastatin was administered alone in increasing concentrations (1μmol/L, 3μmol/L, 5μmol/L and 10μmol/L) and in combination with CCl4 (86μmol/L). The cells were also pretreated with 14μmol/L amiodarone and then the other two compounds were added. RESULTS: Lovastatin promoted concentration-dependent significant toxicity estimated by decrease in cell viability and GSH level by 45% and 84%, respectively. LDHactivity increased by 114% and TBARS content by 90%. CCl4 induced the expected severe damage on the examined parameters. CCU induced toxicity was attenuated after lovastatin pretreatment, which was expressed in less increased values of LDH activity and TBARS levels, as well as in less decreased cell viability and GSH concentrations. However, the pretreatment of hepatocytes with amiodarone abolished the protective effect of lovastatin. CONCLUSION: We suggest that the observed cytopro-tective effect was due to interactions between lovastatin, CCl4 and amiodarone at a metabolic level.
基金International Medical University(IMU),Malaysia for financially supporting the present work under the research grant number BPharm B0108_Res322011.
文摘The aim of present study was to formulate and evaluate a self-microemulsifying drug delivery systems(SMEDDS)containing lovastatin and to further explore the ability of porous Neusilin■ US2 tablet as a solid carrier for SMEDDS.SMEDDS formulations of varying proportions of peceol,cremophor RH 40 and transcutol-P were selected and subjected to invitro evaluation,including dispersibility studies,droplet size,zeta potential measurement and release studies.The results indicated that the drug release profile of lovastatin from SMEDDS formulations was statistically significantly higher(p-value<0.05)than the plain lovastatin powder.Thermodynamic stability studies also confirmed the stability of the prepared SMEDDS formulations.The optimized formulation,which consists of 12% of peceol,44% of cremophor RH 40,and 44% of transcutol-P was loaded into directly compressed liquid loadable tablet of Neusilin■ US2 by simple adsorption method.In order to determine the ability of Neusilin®US2 as a suitable carrier pharmacodynamics study were also carried out in healthy diet induced hyperlipidemic rabbits.Animals were administered with both liquid SMEDDS and solid SMEDDS as well.From the results obtained,Neusilin■ was found to be a suitable carrier for SMEDDS and was equally effective in reducing the elevated lipid profile.In conclusion,liquid loadable tablet(LLT)is predicted to be a promising technique to deliver a liquid formulation in solid state.
基金sponsored by Natural Science Foundation of Xinjiang Uygur Autonomous Region (No.2022DO1A164)the Joint Research Found (No.U1831109)in Astronomy under cooperative agreement between the National Natural Science Foundation of China (NSFC)and Chinese Academy of Sciences (CAS)the Natural Science Foundation of Shandong Province (No.ZR2020QA048)。
文摘Two sets of CCD photometric observations for contact binary TU Boo were obtained in 2020 and 2021.Different from its asymmetric light curves published from the literature,our BVRcIc-band curves show that the heights of maximum are almost equal.These distortions of light curves possibly indicate that the components were active in past 25 yr,but they were stable in the last two years.For total-eclipse binary TU Boo,due to some star-spots on the surface of the components,the physical structure obtained by many investigators are different.Therefore,the symmetric multi-color light curves in 2020,2021 are important for understanding configuration and evolution of this system.By using the Wilson–Devinney program,it is confirmed that TU Boo is an A-type shallow-contact binary with the temperature difference ofΔT=152 K and fill-out of f=14.67%.In the O−C diagram of orbital period analysis,a cyclic oscillation superimposed on a continuous decrease was determined.The long-term decreasing is often explained by the mass transfer from the more massive star to less massive one,this system will evolve into a deeper contact binary with time.The cyclic oscillations computed from much more CCD times of light minimum maybe result from the light-travel time effect via the presence of a third body.These characters of structure,evolution and ternary belong to typical A-type W UMa binaries with spectral G.
