Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 12 de 12
Filter
Add more filters










Publication year range
1.
Sci Rep ; 14(1): 11033, 2024 May 14.
Article in English | MEDLINE | ID: mdl-38744912

ABSTRACT

The presented paper discusses the production of radioactive ion beams of francium, radium, and actinium from thick uranium carbide (UC x ) targets at ISOLDE, CERN. This study focuses on the release curves and extractable yields of francium, radium and actinium isotopes. The ion source temperature was varied in order to study the relative contributions of surface and laser ionization to the production of the actinium ion beams. The experimental results are presented in the form of release parameters. Representative extractable yields per µ C are presented for 222 - 231 Ac, several Ra and Fr isotopes in the mass ranges 214 ≤ A ≤ 233 and 205 ≤ A ≤ 231 respectively. The release efficiency for several isotopes of each of the studied elements was calculated by comparing their yields to the estimated in-target production rates modeled by CERN-FLUKA. The maximal extraction efficiency of actinium was calculated to be 2.1(6)% for a combination of surface ionization using a Ta ion source and resonant laser ionization using the two-step 438.58 nm, and 424.69 nm scheme.

2.
Appl Radiat Isot ; 208: 111289, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38508063

ABSTRACT

At CERN-ISOLDE, high-purity radioactive ion beams of 219Fr and 221RaF were investigated with α-decay spectroscopy at the CRIS and ASET experiments in the course of three different experimental campaigns. The half-life of 215At, α-decay daughter of 219Fr, is measured to be 36.3(3)[9]µs, and that of 221Ra was determined to be 26.2(1)[6]s, both of which are well in line with the trends in this region of the nuclear landscape but at odds with some of the reported literature.

3.
Appl Radiat Isot ; 202: 111044, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37797447

ABSTRACT

Terbium-152 is one of four terbium radioisotopes that together form a potential theranostic toolbox for the personalised treatment of tumours. As 152 Tb decay by positron emission it can be utilised for diagnostics by positron emission tomography. For use in radiopharmaceuticals and for activity measurements by an activity calibrator a high radionuclide purity of the material and an accurate and precise knowledge of the half-life is required. Mass-separation and radiochemical purification provide a production route of high purity 152Tb. In the current work, two mass-separated samples from the CERN-ISOLDE facility have been assayed at the National Physical Laboratory to investigate the radionuclide purity. These samples have been used to perform four measurements of the half-life by three independent techniques: high-purity germanium gamma-ray spectrometry, ionisation chamber measurements and liquid scintillation counting. From the four measurement campaigns a half-life of 17.8784(95) h has been determined. The reported half-life shows a significant difference to the currently evaluated half-life (ζ-score = 3.77), with a relative difference of 2.2 % and an order of magnitude improvement in the precision. This work also shows that under controlled conditions the combination of mass-separation and radiochemical separation can provide high-purity 152Tb.

4.
Appl Radiat Isot ; 190: 110480, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36209648

ABSTRACT

Terbium-155 has been identified for its potential for single-photon emission computed tomography (SPECT) in nuclear medicine. For activity measurements, an accurate and precise half-life of this radionuclide is required. However, the currently evaluated half-life of 5.32(6) d with a relative standard uncertainty of 1.1% determines the precision possible. Limited literature for the half-life measurements of this radionuclide is available and all reported investigations are prior to 1970. Further measurements are therefore needed to confirm the accuracy and improve the precision of the half-life for its use in the clinical setting. Two samples produced and mass separated at the CERN-MEDICIS facility have been measured at the National Physical Laboratory by two independent techniques: liquid scintillation counting and high-purity germanium gamma-ray spectrometry. A half-life of 5.2346(36) d has been determined from the weighted mean of the half-lives determined by the two techniques. The half-life reported in this work has shown a relative difference of 1.6% to the currently evaluated half-life and has vastly improved the precision.


Subject(s)
Nuclear Medicine , Radioisotopes , Half-Life , Radioisotopes/analysis , Tomography, Emission-Computed, Single-Photon/methods , Spectrometry, Gamma
5.
Int J Pharm ; 547(1-2): 169-180, 2018 Aug 25.
Article in English | MEDLINE | ID: mdl-29782971

ABSTRACT

In contact-less printing, such as piezo-electric drop on demand printing used in the study, the drop formation process is independent of the substrate. This means that having developed a printable formulation, printed pharmaceutical dosage forms can be obtained on any pharmaceutical grade substrate, such as polymer-based films. In this work we evaluated eight different oral films based on their suitability as printing substrates for sodium picosulfate. The different polymer films were compared regarding printed spot morphology, chemical stability and dissolution profile. The morphology of printed sodium picosulfate was investigated with scanning electron microscopy and optical coherence tomography. The spreading of the deposited drops was found to be governed by the contact angle of the ink with the substrate. The form of the sodium picosulfate drops changed on microcrystalline cellulose films at ambient conditions over 8 weeks and stayed unchanged on other tested substrates. Sodium picosulfate remained amorphous on all substrates according to small and wide angle X-ray scattering, differential scanning calorimetry and polarized light microscopy measurements. The absence of chemical interactions between the drug and substrates, as indicated by infrared spectroscopy, makes all tested substrates suitable for printing sodium picosulfate onto them.


Subject(s)
Drug Compounding/methods , Drug Delivery Systems , Printing , Administration, Oral , Cellulose/chemistry , Citrates/chemistry , Drug Liberation , Gelatin/chemistry , Hypromellose Derivatives/chemistry , Organometallic Compounds/chemistry , Picolines/chemistry , Titanium/chemistry , Wettability
6.
Z Gerontol Geriatr ; 47(4): 285-7, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24740531

ABSTRACT

Drugs represent the most common intervention strategy for managing acute and chronic medical conditions. In light of demographic change and the increasing age of patients, the classic model of drug research and development by the pharmaceutical industry and drug prescription by physicians is reaching its limits. Different stakeholders, e.g. industry, regulatory authorities, health insurance systems, physicians etc., have at least partially differing interests regarding the process of healthcare provision. The primary responsibility for the correct handling of medication and adherence to treatment schedules lies with the recipient of a drug-based therapy, i.e. the patient. It is thus necessary to interactively involve elderly patients, as well as the other stakeholders, in the development of medication and medication application devices, and in clinical trials. This approach will provide the basis for developing a strategy that better meets patients' needs, thus resulting in improved adherence to treatment schedules and better therapeutic outcomes.


Subject(s)
Clinical Trials as Topic/trends , Drug Design , Drug Industry/trends , Health Services Needs and Demand/trends , Population Dynamics/trends , Aged , Dosage Forms , Forecasting , Germany , Guideline Adherence/trends , Humans , Medication Adherence , Translational Research, Biomedical/trends
7.
Eur J Pharm Sci ; 48(1-2): 181-94, 2013 Jan 23.
Article in English | MEDLINE | ID: mdl-23142635

ABSTRACT

Enhanced therapeutics are drug products derived from existing generic drugs that provide additional benefits to the patients and the healthcare system. Enhanced therapeutics are considered to be an important and relatively low risk source of innovation. Pulmonary drug delivery is the major delivery route to treat chronic respiratory diseases and has been proven as a potential delivery route for complex drugs that cannot be delivered orally. Development of dry powder inhalation systems targets the delivery of fine drug particles to the deep lung surface by a combination of drug formulation, primary packaging and a device, whereby each contributes to the overall performance. Various methodologies for the non-clinical and clinical performance testing of orally inhaled products have been proposed and applied with variable success. Regulatory pathways have been developed and applied since. Considerable efforts have been made during the past decade to understand and optimize pulmonary drug delivery including their efficient commercial manufacturing. Pulmonary drug delivery remains an area of future innovation in the effective treatment of pulmonary diseases as well as the systemic delivery of systemically active complex drugs.


Subject(s)
Drug Delivery Systems , Dry Powder Inhalers , Administration, Inhalation , Drug Delivery Systems/economics , Dry Powder Inhalers/economics , Fees, Pharmaceutical , Humans , Pharmaceutical Preparations/administration & dosage , Pharmacokinetics , Therapeutic Equivalency
8.
Z Gerontol Geriatr ; 45(6): 479-84, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22806640

ABSTRACT

The age appropriateness of a pharmaceutical product for older patient populations is most important in achieving ease of use, administration, and adherence as well as the therapeutic benefit of the drug. Drug development is a lengthy and risky investment accompanied by extensive regulatory requirements to meet all the safety, efficacy, and quality criteria of a pharmaceutical product. Older adults represent a very heterogeneous patient population with different needs compared to younger adults. Major areas that should be considered in the design of age-appropriate products (AAP) are age- and disease-related aspects such as (a) different dose strengths, (b) issues in handling, administering, and managing the drug product, (c) and complex medication regimens. The application of different technologies can meet these specific needs and should be considered at the very beginning of product development when setting the targeted quality product profile (TQPP) or later on during the product life-cycle management.


Subject(s)
Drug Design , Drug Interactions , Drug-Related Side Effects and Adverse Reactions/prevention & control , Polypharmacy , Aged , Aged, 80 and over , Female , Humans , Male , Risk Factors
9.
Int J Pharm ; 430(1-2): 197-206, 2012 Jul 01.
Article in English | MEDLINE | ID: mdl-22525080

ABSTRACT

There is evidence that swallowing issues and dysphagia are an increasing problem of the aging population in the coming decades that is affecting oral medication administration. There is a variety of clinical expressions of swallowing dysfunction caused by aging, acute or chronic disease conditions, decline in physiological functions and adverse drug reactions. About one third of patients in long term care facilities experience serious difficulties with swallowing solid oral dosage forms (SODF). Manipulations of the solid oral drug products occur frequently in nursery homes leading to medication errors and potential changes in drug product performance. The alteration of the drug products is performed with the best intention of the care giver to help the patients but bears concerns about safety and lawfulness. Alternative SODF and drug delivery technologies should be considered in the development of new and generic products and their prescription to overcome medication administration problems in patients with swallowing difficulties of SODF.


Subject(s)
Deglutition Disorders/physiopathology , Deglutition , Pharmaceutical Preparations/administration & dosage , Administration, Oral , Age Factors , Chemistry, Pharmaceutical , Deglutition Disorders/diagnosis , Deglutition Disorders/epidemiology , Deglutition Disorders/therapy , Dosage Forms , Drug Delivery Systems , Drug-Related Side Effects and Adverse Reactions , Humans , Pharmaceutical Preparations/chemistry , Prevalence , Risk Factors , Technology, Pharmaceutical/methods
10.
Eur J Pharm Sci ; 31(5): 249-61, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17616376

ABSTRACT

Drug absorption, sufficient and reproducible bioavailability and/or pharmacokinetic profile in humans are recognized today as one of the major challenges in oral delivery of new drug substances. The issue arose especially when drug discovery and medicinal chemistry moved from wet chemistry to combinatorial chemistry and high throughput screening in the mid-1990s. Taking into account the drug product development times of 8-12 years, the apparent R&D productivity gap as determined by the number of products in late stage clinical development today, is the result of the drug discovery and formulation development in the late 1990s, which were the early and enthusiastic times of the combinatorial chemistry and high throughput screening. In parallel to implementation of these new technologies, tremendous knowledge has been accumulated on biological factors like transporters, metabolizing enzymes and efflux systems as well as on the physicochemical characteristics of the drug substances like crystal structures and salt formation impacting oral bioavailability. Research tools and technologies have been, are and will be developed to assess the impact of these factors on drug absorption for the new chemical entities. The conference focused specifically on the impact of compounds with poor solubility on analytical evaluation, prediction of oral absorption, substance selection, material and formulation strategies and development. The existing tools and technologies, their potential utilization throughout the drug development process and the directions for further research to overcome existing gaps and influence these drug characteristics were discussed in detail.


Subject(s)
Combinatorial Chemistry Techniques/methods , Drug Design , Administration, Oral , Biological Availability , Humans , Intestinal Absorption , Pharmaceutical Preparations/administration & dosage , Pharmaceutical Preparations/chemical synthesis , Pharmaceutical Preparations/chemistry , Pharmacokinetics , Solubility
11.
Cephalalgia ; 23(8): 790-802, 2003 Oct.
Article in English | MEDLINE | ID: mdl-14510925

ABSTRACT

In spite of the fact that migraine often manifests as a familial disorder, the role of the family in migraine has not been adequately explored. In this study parent-child interactions in 20 families with a child suffering from migraine were analysed and compared with 20 healthy families and 20 families with an asthma child. The families had to solve a puzzle within a limited time. Parent-child interactions within migraine and asthma families were asymmetric, revealing a disease-specific interpersonal context in the family. Communication with the affected child in migraine families was significantly more directive, with more specific instructions and less help, towards migraineurs than with the healthy siblings. Dominance of parents and submissive behaviour of children were the main features of interactions. In asthma families interactions were more conflicting and less cooperative. This study demonstrated a specific, asymmetric, pattern of family interactions predisposing children either to migraine or asthma.


Subject(s)
Asthma/psychology , Migraine Disorders/psychology , Parent-Child Relations , Adolescent , Adult , Analysis of Variance , Asthma/epidemiology , Chi-Square Distribution , Child , Female , Humans , Male , Middle Aged , Migraine Disorders/epidemiology
12.
Radiat Environ Biophys ; 32(1): 65-72, 1993.
Article in English | MEDLINE | ID: mdl-8460216

ABSTRACT

A thirty-minute exposure of mice to a homogeneous stationary magnetic field (SMF) of 1.4 Tesla at either 27 degrees C or 37 degrees C body temperature causes an inhibition of about 20 per cent of acetylcholinesterase (AChE, E.C. 3.11.7) in murine bone marrow cells (BMC) after 3.5 and 2 h, respectively, at the two aforementioned body temperatures. The extent of enzyme inhibition is independent of ambient temperature, but dependent on the time after exposure. This initial inhibition of AChE activity is followed by a limited recovery which is dependent upon the temperature during exposure to the SMF and remains incomplete even 15 h afterwards. We describe here certain enzymologic properties of AChE in BMC as well as inhibition studies with diisopropylfluorophosphate (DFP) to differentiate between AChE and nonspecific cholinesterases.


Subject(s)
Acetylcholinesterase/radiation effects , Bone Marrow/radiation effects , Magnetics , Animals , Bone Marrow/enzymology , Bone Marrow Cells , Cholinesterase Inhibitors/pharmacology , Erythroid Precursor Cells/enzymology , Erythroid Precursor Cells/radiation effects , Female , In Vitro Techniques , Isoflurophate/pharmacology , Megakaryocytes/enzymology , Megakaryocytes/radiation effects , Mice , Mice, Inbred Strains , Substrate Specificity
SELECTION OF CITATIONS
SEARCH DETAIL
...