Study on pharmacokinetics of nimodipine nano-controlled release agent modified by host-guest reaction of β-cyclodextrin in rats

2021 ◽  
Vol 11 (6) ◽  
pp. 839-845
Author(s):  
Xiaoxiu Fu ◽  
Lin Ma ◽  
Yang Cao ◽  
Hengzhong Xu ◽  
Yan Guo
Keyword(s):  
Controlled Release ◽  
The Elderly ◽  
Rat Plasma ◽  
Cerebrovascular Diseases ◽  
Absolute Bioavailability ◽  
Release Agent ◽  
Dihydropyridine Calcium Channel Antagonist ◽  
Oral Preparation ◽  
Ischemic Cerebrovascular Diseases ◽  
The Stability

Nimodipine (NIMO) has been identified as a second-generation dihydropyridine calcium channel antagonist. NIMO’s specificity for the cerebrovascular smooth muscle contributes to its broad usage in treating ischemic cerebrovascular diseases in the elderly. Therefore, enhancing NIMO’s therapeutic effect and reducing its adverse reactions caused by short-term repeated use have become a focus of research. As a result, a new controlled-release preparation of NIMO, the carboxymethyl chitosan/nimodipine-hydroxypropyl-β-cyclodextrin nanoparticle (Nano-NIMO), was constructed based on hydroxypropyl-β-cyclodextrin. The novel composite Nano-NIMO preparation could significantly improve the stability of NIMO in rat plasma, achieving an absolute bioavailability as high as 62.3%, which is three times that of the traditional NIMO oral preparation. Therefore, Nano-NIMO is expected to provide a new direction for the preparation of modified controlled-release Nano- NIMO agents.

scholarly journals Stereo-Selective Pharmacokinetics of Ilimaquinone Epimers Extracted from a Marine Sponge in Rats

Marine Drugs ◽  
2019 ◽  
Vol 17 (3) ◽  
pp. 171 ◽  
Author(s):  
Heebin Son ◽  
Keumhan Noh ◽  
InWha Park ◽  
MinKyun Na ◽  
Sangtaek Oh ◽  
...  
Keyword(s):  
Plasma Concentrations ◽  
Elimination Rate ◽  
Systemic Exposure ◽  
Rat Plasma ◽  
Absolute Bioavailability ◽  
Anti Cancer ◽  
The Stability ◽  
The Individual ◽  
Intravenous And Oral Administration

An ilimquinone (IQ) mixture isolated from Hippiospongia metachromia, consisting of IQ and epi-ilimaquinone (epi-IQ), exerts anti-HIV, anti-microbial, anti-inflammatory, and anti-cancer effects. An HPLC-MS/MS method was developed for simultaneous determination of the two epimers in rat plasma, separating them using a biphenyl column. Ascorbic acid is added during the sample preparation to ensure the stability of both isomers. The plasma concentrations of the isomers were monitored following intravenous and oral administration of the IQ mixture in rats as well as the individual epimers that were separately orally administered. Compare to IQ, epi-IQ was much more stable in rat plasma, likely due to its configurations of decalin. Both substances decayed in more than bi-exponential pattern, with an elimination rate constant of 1.2 h−1 for IQ and 1.7 h−1 for epi-IQ. The epi-IQ was distributed more widely than IQ by about two-fold. Consequently, the clearance of epi-IQ was greater than that of IQ by about three-fold. The oral absolute bioavailability for IQ was 38%, and, that for epi-IQ, was 13%. Although the systemic exposure of IQ was greater than that of epi-IQ by ~8.7-fold, the clearance of each isomer was similar when administered either orally or intravenously, when normalized for bioavailability. The stereo-specific behavior of the isomers appears to originate from differences in both their tissue distribution and gastrointestinal permeability.

scholarly journals Pharmacokinetics of five phthalides in volatile oil of Ligusticum sinense Oliv.cv. Chaxiong, and comparison study on physicochemistry and pharmacokinetics after being formulated into solid dispersion and inclusion compound

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Peng-yi Hu ◽  
Ying-huai Zhong ◽  
Jian-fang Feng ◽  
Dong-xun Li ◽  
Ping Deng ◽  
...  
Keyword(s):  
Oral Administration ◽  
Solid Dispersion ◽  
Oral Bioavailability ◽  
Inclusion Compound ◽  
Phosphate Buffer Solution ◽  
Volatile Oil ◽  
Rat Plasma ◽  
Cerebrovascular Diseases ◽  
Absolute Bioavailability ◽  
Buffer Solution

Abstract Backgrounds The dried rhizome of Ligusticum sinense Oliv.cv. Chaxiong has been used to treat cardiovascular and cerebrovascular diseases, atherosclerosis, anemia and stroke. A high purity extract from chaxiong (VOC, brownish yellow oil) was extracted and separated. Its main components were senkyunolide A (SA, 33.81%), N-butylphthalide (NBP, 1.38%), Neocnidilide (NOL, 16.53%), Z-ligustilide (ZL, 38.36%), and butenyl phthalide (BP, 2.48%), respectively. Little is known about the pharmacokinetics of these phthalides in Chaxiong, and different preparations to improve the physicochemistry and pharmacokinetics of VOC have not been investigated. Methods At different predetermined time points after oral administration or intravenous administration, the concentrations of SA, NBP, NOL, ZL and BP in the rat plasma were determined using LC-MS/MS, and the main PK parameters were investigated. VOC-P188 solid dispersion and VOC-β-CD inclusion compound were prepared by melting solvent method and grinding method, respectively. Moreover, the physicochemical properties, dissolution and pharmacokinetics of VOC-P188 solid dispersion and VOC-β-CD inclusion compound in rats were assessed in comparison to VOC. Results The absorptions of SA, NBP, NOL, ZL and BP in VOC were rapid after oral administration, and the absolute bioavailability was less than 25%. After the two preparations were prepared, dissolution rate was improved at pH 5.8 phosphate buffer solution. Comparing VOC and physical mixture with the solid dispersion and inclusion compound, it was observed differences occurred in the chemical composition, thermal stability, and morphology. Both VOC-P188 solid dispersion and VOC-β-CD inclusion compound had a significantly higher AUC and longer MRT in comparison with VOC. Conclusion SA, NBP, NOL, ZL and BP in VOC from chaxiong possessed poor absolute oral bioavailability. Both VOC-P188 solid dispersion and VOC-β-CD inclusion compound could be prospective means for improving oral bioavailability of SA, NBP, NOL, ZL and BP in VOC.

Dyspnea Possibly Associated with Controlled-Release Morphine Sulfate Tablets

1988 ◽  
Vol 22 (5) ◽  
pp. 397-399 ◽  
Author(s):  
Harry D. Kerr
Keyword(s):  
Elderly Patient ◽  
Controlled Release ◽  
Severe Pain ◽  
The Elderly ◽  
Morphine Sulfate ◽  
Tablet Form ◽  
Respiratory Effects ◽  
Oral Preparation ◽  
Adenocarcinoma Of The Prostate ◽  
Chronic Severe Pain

Morphine sulfate in controlled-release tablet form is a relatively new oral preparation being used for the relief of chronic severe pain, such as that related to cancer. A patient with adenocarcinoma of the prostate with bone metastases experienced dyspnea possibly related to the ingestion of these tablets. Discontinuing the drug quickly resulted in disappearance of the dyspnea. The respiratory effects of morphine and the particular risks posed to the elderly patient are discussed.

scholarly journals Barrier-Free Wheelchair with a Mechanical Transmission

2021 ◽  
Vol 11 (11) ◽  
pp. 5280
Author(s):  
Jongseok Lee ◽  
Wonhyeong Jeong ◽  
Jaeoh Han ◽  
Taesu Kim ◽  
Sehoon Oh
Keyword(s):  
The Elderly ◽  
Transmission System ◽  
Motor Drives ◽  
Mechanical Transmission ◽  
Link Structure ◽  
Second Mode ◽  
Important Means ◽  
The Stability ◽  
Flat Ground ◽  
Climbing Stairs

Wheelchairs are an important means of transportation for the elderly and disabled. However, the movement of wheelchairs on long curbs and stairs is restricted. In this study, a wheelchair for climbing stairs was developed based on a mechanical transmission system that rotates the entire driving part through a link structure and an actuator to change the speed. The first mode drives the caterpillar, and the second mode drives the wheels. When driving on flat ground, it uses landing gears and wheels, and when climbing stairs, it uses the caterpillar; accordingly, a stable driving is possible. The stability of the transmission is confirmed through stress analysis. The method used in our study makes it is possible to manufacture lightweight wheelchairs because a single motor drives both the wheel and caterpillar through the transmission system.

Potential Protective Effect of Dl-3-n-Butylphthalide on Chronic Cerebral Ischemia Brain Injury

2021 ◽  
Vol 21 ◽  
Author(s):  
Fangfang Zhao ◽  
Yumin Luo
Keyword(s):  
Oxidative Stress ◽  
Cerebral Ischemia ◽  
Brain Dysfunction ◽  
Cerebrovascular Diseases ◽  
Pathophysiological Mechanism ◽  
Chronic Cerebral Ischemia ◽  
Celery Seed ◽  
Prevention And Treatment ◽  
Ischemic Cerebrovascular Diseases ◽  
The Common

: Chronic cerebral ischemia is one of the common ischemic cerebrovascular diseases. Chronic cerebral ischemia can lead to brain dysfunction, and its pathophysiological mechanism involves inflammation, blood-brain barrier destruction, oxidative stress, and other factors. Due to it being difficult to detect, it is easily overlooked, and it is often only observed following onset of cognitive dysfunction. At present, there are few drugs for this treatment. DL-3-N-BUTYLPHTHALIDE (NBP), a compound extracted from celery seed, may play an important role in protecting against brain damage caused by chronic cerebral ischemia. Therefore, we pay more attention to the prevention and treatment of NBP on chronic cerebral ischemia.

Remaking Medicare: The Voucher Myth

1998 ◽  
Vol 28 (1) ◽  
pp. 29-46
Author(s):  
Jonathan Oberlander
Keyword(s):  
Consumer Choice ◽  
Baby Boom ◽  
Market Competition ◽  
The Elderly ◽  
Medicare Beneficiaries ◽  
Short Term ◽  
Medicare Program ◽  
The Stability ◽  
Voucher System

There is growing enthusiasm for transforming Medicare into a voucher system. Advocates claim vouchers would increase the health care choices available to Medicare beneficiaries, reduce the regulatory burden on the federal government, and promote the benefits of fair market competition. In addition, some analysts contend vouchers are the only feasible solution to Medicare's short-term financing problems and the long-term “crisis” of the retirement of the baby-boom generation. The author argues against these claims. Vouchers would not work as advertised by proponents because of the limitations of risk-adjustment methods and unrealistic assumptions about consumer choice. Moreover, the elderly and disabled Medicare population is ill-suited to cope in a competitive insurance system. Implementation of vouchers would therefore pose a threat to both the health of beneficiaries and the stability of the Medicare program. The implications of this analysis for Medicare reform are discussed.

scholarly journals The Vulnerability of Vessels Involved in the Role of Embolism and Hypoperfusion in the Mechanisms of Ischemic Cerebrovascular Diseases

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Yong Peng Yu ◽  
Lan Tan
Keyword(s):  
Cerebral Infarction ◽  
Dominant Role ◽  
Cerebrovascular Diseases ◽  
Effective Care ◽  
Cerebrovascular Events ◽  
Accurate Definition ◽  
Ischemic Cerebrovascular Diseases ◽  
Vascular Stenosis

Accurate definition and better understanding of the mechanisms of stroke are crucial as this will guide the effective care and therapy. In this paper, we review the previous basic and clinical researches on the causes or mechanisms of ischemic cerebrovascular diseases (ICVD) and interpret the correlation between embolism and hypoperfusion based on vascular stenosis and arterial intimal lesions. It was suggested that if there is no embolus (dynamic or in situ emboli), there might be no cerebral infarction. Three kinds of different clinical outcomes of TIA were theoretically interpreted based on its mechanisms. We suppose that there is a correlation between embolism and hypoperfusion, and which mechanisms (hypoperfusion or hypoperfusion induced microemboli) playing the dominant role in each type of ICVD depends on the unique background of arterial intimal lesions (the vulnerability of vessels). That is to say, the vulnerability of vessels is involved in the role of embolism and hypoperfusion in the mechanisms of ischemic cerebrovascular diseases. This inference might enrich and provide better understandings for the underlying etiologies of ischemic cerebrovascular events.

scholarly journals Overview of hospitalizations by ambulatory care sensitive conditions in the municipality of Cotia, Brazil

2014 ◽  
Vol 48 (spe) ◽  
pp. 137-144
Author(s):  
Renata Laszlo Torres ◽  
Suely Itsuko Ciosak
Keyword(s):  
Heart Failure ◽  
Urinary Tract ◽  
The Elderly ◽  
Cerebrovascular Diseases ◽  
Descriptive Statistics ◽  
Ambulatory Care Sensitive Conditions ◽  
Age Group ◽  
Unified Health System ◽  
Significant Difference ◽  
Sensitive Conditions

Objective To describe the profile of Hospitalizations by Amulatory Care Sensitive Conditions (HACSC), in the Municipality of Cotia, from 2008 to 2012. Method ecological, exploratory, longitudinal study with a quantitative approach. Data on HACSC, by age group and sex, were obtained from the Department of the Unified Health System. For data analysis descriptive statistics were used. Results During the period, there were 46,676 admissions, excluding deliveries, 7,753 (16.61%) by HACSC. The main causes were cerebrovascular diseases, 16.96%, heart failure, 15.50%, hypertension, 10.80% and infection of the kidney and urinary tract, 10.51%. Regarding gender, HACSC occurred predominantly in males. There was a greater number of HACSC at extreme age ranges, especially in the elderly. Conclusion Chronic diseases predominate among the leading causes of HACSC and there was no significant difference between sex.





scholarly journals LC-MS/MS Method for Simultaneous Quantification of Dexmedetomidine, Dezocine, and Midazolam in Rat Plasma and Its Application to Their Pharmacokinetic Study

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Wenjuan Cui ◽  
Qin Liu ◽  
Shan Xiong ◽  
Lujun Qiao
Keyword(s):  
Storage Conditions ◽  
Rat Plasma ◽  
Selected Reaction Monitoring ◽  
Pharmacokinetic Studies ◽  
Reaction Monitoring ◽  
Simultaneous Quantification ◽  
Ionization Mode ◽  
The Stability ◽  
Lower Limits ◽  
Interday Precision

A simple, sensitive, and accurate LC-MS/MS method was established and validated for the simultaneous quantification of dexmedetomidine, dezocine, and midazolam in rat plasma. Chromatographic separation was achieved on a C18 column (50 mm × 2.1 mm, 3 µm) using a mobile phase composed of water (containing 0.1% formic acid) and acetonitrile. The lower limits of quantification were 0.1, 0.1, and 0.2 ng/mL for dexmedetomidine, dezocine, and midazolam in rat plasma, respectively. The analytes were determined with selected reaction monitoring under positive ionization mode. The intra- and interday precision and accuracy were all within acceptable limits during the entire validation, and the stability of analytes was acceptable under various storage conditions. The validated method was successfully applied in pharmacokinetic studies of dexmedetomidine, dezocine, and midazolam following intravenous injection.

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