China
Africa
Explore chapters and articles related to this topic
Verifying Thermal Imager Calibration
Published in James Stewart Campbell, M. Nathaniel Mead, Human Medical Thermography, 2023
James Stewart Campbell, M. Nathaniel Mead
where Tflatness is the maximum temperature difference over the image.Tmax is the maximum temperature reading among the measurements.Tmin is the minimum temperature reading among the measurements.@Troom means the image is taken at a nominal room temperature.
Nanocarriers Systems and Their Application for the Delivery of Different Phytoconstituents
Published in Madhu Gupta, Durgesh Nandini Chauhan, Vikas Sharma, Nagendra Singh Chauhan, Novel Drug Delivery Systems for Phytoconstituents, 2020
Ebru Altuntaş, Gülgün Yener, Burcu Özkan
It has been shown that an active component named Oxymatrine (OMT), extracted from Sophora flavescens, possesses antiproliferation and antioxidative characteristics (Guzman et al., 2013, Jayaprakasam et al., 2013, Jin et al., 2010). OMT is applied for treating viral hepatitis (Liu et al., 2016), ischemia reperfusion injury, and bronchial asthma in China (Yuan et al., 2011). OMT–phospholipid complex (OMT–PLC) was developed with the aim of improving the bioavailability of OMT by Yue et al. (2010). Optimum conditions for the process were 3 hours of reaction time, 60°C of reaction temperature, and 3:1 of the OMT-PLC ratio. An improvement of the mean Cmax value of 0.164 μg/mL was obtained on the oral use of a drug solution at a dose of 0.437 μg/mL, and on the oral use of the phospholipid complex at a dose of 100 mg/kg of OMT administered to rats. Detection of Tmax as 2.17 and 1.71 hours, respectively, in drug solution and complex applications, suggests that the plasma drug concentration has a sustained pattern. The AUC of OMT-PLC (9.43 μg−1 h) elevated considerably to that of free OMT (2.87 μg−1 h) in rats administered via oral route. The overall bioavailability of OMT complex has been shown to be 3.29 times greater compared to OMT.
History and Regulation of Bioequivalence
Published in Scott Patterson, Byron Jones, Bioequivalence and Statistics in Clinical Pharmacology, 2017
In cases where multiple “peaks” in blood concentration are observed, it is common practice for the first [373] to be chosen as Cmax, with the corresponding time relative to dose being Tmax. The value of Tmax is highly dependent on the choice of sampling times. Its use in bioequivalence studies is that of an endpoint providing supportive information. Some nations [140, 141] require that Tmax be analyzed as if it were normally distributed.
Acacetin-loaded microemulsion for transdermal delivery: preparation, optimization and evaluation
Published in Pharmaceutical Biology, 2023
Yajing Wang, Qian Chen, Xianfeng Huang, Xiaojing Yan
The mean acacetin plasma concentration-time profiles after transdermal administration are shown in Figure 6. Pharmacokinetic parameters such as maximal plasma drug concentration (Cmax) and time to maximal plasma drug concentration (Tmax) were read directly from individual plasma concentration-time profiles. The duration time of action was analyzed and obtained by correlation with the therapeutic window (61.1 ∼ 650 ng/mL obtained in experimental persistent AF). The area under the concentration-time curve from time 0 to t (AUC0-t) was calculated by the linear up-log-down rule. As shown in Table 2, FB exhibited considerably higher Cmax and improved bioavailability in comparison with FA. The AUC0-t of FC is slightly higher than FB, but it’s not significant due to big variation. FC presented a faster permeation rate than FA and FB especially at the early post-administration time points. These results are in good agreement with the ex vivo permeability data.
Phosphodiesterase 5 inhibitors: preclinical and early-phase breakthroughs for impotence treatments
Published in Expert Opinion on Investigational Drugs, 2023
Zachary Melchiode, Tivoli Nguyen, Omar Dawood, Graham A. Bobo, Wayne J.G. Hellstrom
Following ingestion of lodenafil, the carbonate bridge is cleaved to yield two active lodenafil molecules [34,35]. Clinical trials have demonstrated a Tmax of 1.2 hours and a half-life of 2.36 hours [36]. Studies have documented that the compound enhances NO-dependent relaxation induced by ACh or electrical stimulation in isolated rat and human penile tissue [35,36]. Additionally, lodenafil was noted to be twice as potent as sildenafil in inhibiting the hydrolysis of cGMP in human platelet extracts [37]. However, it is important to note that increased potency was observed in an in vitro investigation involving different tissue from humans, dogs, and rats, thus raising concerns about the drug’s pharmacological profile [37]. The current studies on lodenafil fail to incorporate data regarding the effect of food on the pharmacokinetics of this drug, an interaction which directly influences patients’ adherence and satisfaction with drug therapy.
Tafenoquine for the treatment of Plasmodium vivax malaria
Published in Expert Opinion on Pharmacotherapy, 2022
Alejandro Llanos-Cuentas, Paulo Manrrique, Angel Rosas-Aguirre, Sonia Herrera, Michelle S. Hsiang
TFQ has a linear pharmacokinetic with increasing doses from 4 to 600 mg, and low intra-individual variability [32]. Protein binding of TFQ is greater than 99.5%, and the volume of distribution (Vd) is high [24,32]. Plasma Vd and the corresponding clearance (CL) values are 1.8 times higher than those of whole blood. The drug has a long absorption phase, likely distally in the gastrointestinal tract, and low CL, explaining the prolonged time to peak concentration (Tmax), which is ~14 hours. In healthy individuals, body weight and race were not associated with Vd or CL [32,36]. The elimination half-life (t1/2) of TFQ is 14 ± 4.04 days, which is more than 50 times longer than that of PQ [27,32,36]. A single 300 mg dose of TFQ is detected for more than 5 weeks, while PQ at a daily dose of 15 mg for 14 days is not detected a day or two after the last dose [32]. Its activity against sporozoites, the pre-erythrocytic stage of Plasmodium, is lower compared to PQ [53]. But as TFQ accumulates in red blood cells, it is a better schizonticide than PQ [32]. With a hematocrit of 45%, the concentration of TFQ in erythrocytes is 2.8 times higher than in plasma [32].