• Archives of Pharmacal Research
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• v.28 no.10
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• pp.1190-1195
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• 2005

The objective of this study was to develop an assay for mequitazine (MQZ) for the study of the bioavailability of the drug in human subjects. Using one mL of human plasma, the pH of the sample was adjusted and MQZ in the aqueous phase extracted with hexane; the organic layer was then evaporated to dryness, reconstituted and an aliquot introduced to a gas chromatograph/mass spectrometer (GC/MS) system with ion-trap detector. Inter- and intra-day precision of the assay were less than 15.1 and $17.7{\%}$, respectively; Inter- and intra-day accuracy were less than 8.91 and $18.6{\%}$, respectively. The limit of quantification for the current assay was set at 1 ng/mL. To determine whether the current assay is applicable in a pharmacokinetic study for MQZ in human, oral formulation containing 10 mg MQZ was administered to healthy male subjects and blood samples collected. The current assay was able to quantify MQZ levels in most of the samples. The maximum concentration ($C_{max}$ was 8.5 ng/mL, which was obtained at 10.1 h, with mean half-life of approximately 45.5 h. Under the current sampling protocol, the ratio of $AUC_{t{\rightarrow}last}$ to $AUC_{t{\rightarrow}{\infty}}$ was $934{\%}$, indicating that the blood collection time of 216 h is reasonable for MQZ. Therefore, these observations indicate that an assay for MQZ in human plasma is developed by using GC/MS with ion-trap detector and validated for the study of pharmacokinetics of single oral dose of 10 mg MQZ, and that the current study design for the bioavailability study is adequate for the drug.

• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.117-128
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• 2018

Purpose : To evaluate the usability of plan transfer between TOMO HD and Radixact, we compared the differences of dose in transferred plans by evaluating the dose of normal organ and target. TOMO HDA and Radixact. The completed plans were transferred each other and we compared the differences of dose by evaluating the DVH of each plans. Materials and Methods : We planned 4 different plans assuming the treatment of 2 cases in Head and Neck Cancer and 2 cases Prostate cancer. Each plan was designed so that 95 % of the prescription dose was irradiated over 99 % of the target volume, and the normal organ constraints dose was based on the SMC tolerance dose protocol. Each plan was transferred to each equipment and DVH(dose volume histogram) analysis of the transferred plans was compared and evaluated. Results : The Mean dose of CTV and GTV was increased and decreased in the transferred plans, but there was no significant differences. The target coverage of CTV and GTV was decreased in all cases of transferred plans from TOMO HAD to Radixact, and the change of CI and HI in CTV was within 0.1. Normal organ dose was increased in most cases when transferring from HAD to Radixact in both treatment plans. Conclusion : According to the results of this experiment, the target coverage was above the standard and the normal organ dose was almost same or decreased when transferring the plans from Radixact to HDA equipment. However the target coverage was reduced when transferring the plans from HDA to Radixact and there was an increase in dose in normal organs that could cause sever side effects such as Optic Chiasm ($D_{max}$1.38 Gy), Bladder ($D_{max}$3.07 Gy), Penile Bulb ($D_{max}$1.14 Gy). Therefore, it is necessary to pay attention to the dose change when transferring the plan and one-time transfer due to equipment inspection will be useful for efficient radiation therapy, but if the transferred treatment plans continue for several consecutive days, the treatment plan should be resumed.