scholarly journals Modern polymers in prolonged release tablet technology

2020 ◽  
Vol 2 (1) ◽  
pp. 36-43
Author(s):  
Julia M. Kotsur ◽  
Elena V. Flisyuk
Keyword(s):  
Release Kinetics ◽  
Active Pharmaceutical Ingredient ◽  
Delivery Systems ◽  
Prolonged Release ◽  
Third Generation ◽  
Medicinal Substance ◽  
Continuous Release ◽  
Pharmaceutical Substances ◽  
Made In

Currently, the delivery systems of second and third generation are of particular interest among pharmaceutical forms. Second generation pharmaceutical forms include systems with prolonged release of the active substance, third generation pharmaceutical forms include systems with controlled release. A slow continuous release of a medicinal substance may be achieved by using special excipients or by using special technologies. For the production of tablets with prolonged release, the most common are special excipients, namely, polymers and their compositions. The use of polymers as carriers of pharmaceutical substances used to program the kinetic frequency and location of the release is known since the middle of XX century [9]. To date, significant progress has been made in the use of polymers to prolong the release: the influence and interaction of polymers and drugs have been studied, the mechanisms of drug release have been studied, ways of programming release kinetics using various properties of polymers, etc. In the article the modern state in the field of technology of tablets with prolonged release is considered. Advantages of prolonged release, mathematical models for description of drug forms with prolonged release are described. Technologies of tablets with prolonged release, types of delivery systems and mechanisms of release of an active pharmaceutical ingredient are considered. The article presents modern polymers that are used in the technology of tablets with prolonged release. The classification of polymers in relation to water and to physiological liquids is presented.

ASPECTS IN BUILDING A COMPANY WEB-SITE AND ITS ROLE FOR THE DEVELOPMENT OF BUSINESS

2018 ◽  
pp. 117-124
Author(s):  
Petar Halachev ◽  
Victoria Radeva ◽  
Albena Nikiforova ◽  
Miglena Veneva
Keyword(s):  
Life Cycle ◽  
Web Site ◽  
The Internet ◽  
A Company ◽  
The Web ◽  
Design Construction ◽  
Made In ◽  
Site Types

This report is dedicated to the role of the web site as an important tool for presenting business on the Internet. Classification of site types has been made in terms of their application in the business and the types of structures in their construction. The Models of the Life Cycle for designing business websites are analyzed and are outlined their strengths and weaknesses. The stages in the design, construction, commissioning, and maintenance of a business website are distinguished and the activities and requirements of each stage are specified.

Vegetation on technogenic habitats in the far-north taiga and south forest-tundra of the European North-East of Russia. Alliance Chamerio angustifolii–Matricarion hookeri A. Ishbirdin et al. 1996

2019 ◽  
pp. 77-94
Author(s):  
I. A. Likhanova ◽  
G. S. Shushpannikova ◽  
L. P. Turubanova
Keyword(s):  
Komi Republic ◽  
Oil Fields ◽  
Soil Enrichment ◽  
Far North ◽  
North East ◽  
European North ◽  
Ecological Scales ◽  
Floristic Classification ◽  
Made In

The results of floristic classification of technogenic vegetation (alliance Chamerio angustifolii–Matricarion hookeri A. Ishbirdin et al. 1996, order Chamerio–Betuletalia nanae Khusainov et al. in Sumina 2012, class Matricario–Poetea arcticae A. Ishbirdin in Sumina 2012) conducted by the Braun-Blanquet method (Braun-Blanquet, 1964; Mirkin, Naumova, 1998) are given. 98 geobotanical relevés, made in 1981–2013 on areas of oil fields and suburbs of the Usinsk city (Komi Republic) (56–60о N, 67–66о E), were involved into analysis (Fig. 1). The ecological parameters like moisture (F) and mineral nitrogen soil enrichment (N) were assessed using the Ellenberg ecological scales (Ellenberg, 1974).

Design of Lamivudine Loaded Nanoparticles for Oral Application by Nano Spray Drying Method: A New Approach to use an Antiretroviral Drug for Lung Cancer Treatment

2020 ◽  
Vol 23 (10) ◽  
pp. 1064-1079
Author(s):  
Ahmet Alper Öztürk ◽  
İrem Namlı ◽  
Kadri Güleç ◽  
Şennur Görgülü
Keyword(s):  
Lung Cancer ◽  
Cancer Treatment ◽  
Anticancer Activity ◽  
Cell Line ◽  
Anticancer Drugs ◽  
Release Kinetics ◽  
Prolonged Release ◽  
Lung Cancer Treatment ◽  
Anticancer Properties ◽  
Ft Ir

Aims: To prepare lamivudine (LAM)-loaded-nanoparticles (NPs) that can be used in lung cancer treatment. To change the antiviral indication of LAM to anticancer. Background: The development of anticancer drugs is a difficult process. One approach to accelerate the availability of drugs is to reclassify drugs approved for other conditions as anticancer. The most common route of administration of anticancer drugs is intravenous injection. Oral administration of anticancer drugs may considerably change current treatment modalities of chemotherapy and improve the life quality of cancer patients. There is also a potentially significant economic advantage. Objective: To characterize the LAM-loaded-NPs and examine the anticancer activity. Methods: LAM-loaded-NPs were prepared using Nano Spray-Dryer. Properties of NPs were elucidated by particle size (PS), polydispersity index (PDI), zeta potential (ZP), SEM, encapsulation efficiency (EE%), dissolution, release kinetics, DSC and FT-IR. Then, the anticancer activity of all NPs was examined. Results: The PS values of the LAM-loaded-NPs were between 373 and 486 nm. All NPs prepared have spherical structure and positive ZP. EE% was in a range of 61-79%. NPs showed prolonged release and the release kinetics fitted to the Weibull model. NPs structures were clarified by DSC and FT-IR analysis. The results showed that the properties of NPs were directly related to the drug:polymer ratio of feed solution. NPs have potential anticancer properties against A549 cell line at low concentrations and non-toxic to CCD 19-Lu cell line. Conclusion: NPs have potential anticancer properties against human lung adenocarcinoma cells and may induce cell death effectively and be a potent modality to treat this type of cancer. These experiments also indicate that our formulations are non-toxic to normal cells. It is clear that this study would bring a new perspective to cancer therapy.

Nanoporous anodic titanium dioxide layers as potential drug delivery systems: Drug release kinetics and mechanism

2016 ◽  
Vol 143 ◽  
pp. 447-454 ◽  
Author(s):  
Magdalena Jarosz ◽  
Anna Pawlik ◽  
Michał Szuwarzyński ◽  
Marian Jaskuła ◽  
Grzegorz D. Sulka
Keyword(s):  
Drug Delivery ◽  
Titanium Dioxide ◽  
Drug Release ◽  
Drug Delivery Systems ◽  
Release Kinetics ◽  
Delivery Systems ◽  
Kinetics And Mechanism ◽  
Potential Drug ◽  
Drug Release Kinetics

scholarly journals pH-Responsive Release of Ruthenium Metallotherapeutics from Mesoporous Silica-Based Nanocarriers

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 460
Author(s):  
Minja Mladenović ◽  
Ibrahim Morgan ◽  
Nebojša Ilić ◽  
Mohamad Saoud ◽  
Marija V. Pergal ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Mesoporous Silica ◽  
Inductively Coupled Plasma ◽  
Drug Delivery Systems ◽  
Mesoporous Silica Nanoparticles ◽  
Release Kinetics ◽  
Delivery Systems ◽  
Emission Spectrometry ◽  
Ph Responsive

Ruthenium complexes are attracting interest in cancer treatment due to their potent cytotoxic activity. However, as their high toxicity may also affect healthy tissues, efficient and selective drug delivery systems to tumour tissues are needed. Our study focuses on the construction of such drug delivery systems for the delivery of cytotoxic Ru(II) complexes upon exposure to a weakly acidic environment of tumours. As nanocarriers, mesoporous silica nanoparticles (MSN) are utilized, whose surface is functionalized with two types of ligands, (2-thienylmethyl)hydrazine hydrochloride (H1) and (5,6-dimethylthieno[2,3-d]pyrimidin-4-yl)hydrazine (H2), which were attached to MSN through a pH-responsive hydrazone linkage. Further coordination to ruthenium(II) center yielded two types of nanomaterials MSN-H1[Ru] and MSN-H2[Ru]. Spectrophotometric measurements of the drug release kinetics at different pH (5.0, 6.0 and 7.4) confirm the enhanced release of Ru(II) complexes at lower pH values, which is further supported by inductively coupled plasma optical emission spectrometry (ICP-OES) measurements. Furthermore, the cytotoxicity effect of the released metallotherapeutics is evaluated in vitro on metastatic B16F1 melanoma cells and enhanced cancer cell-killing efficacy is demonstrated upon exposure of the nanomaterials to weakly acidic conditions. The obtained results showcase the promising capabilities of the designed MSN nanocarriers for the pH-responsive delivery of metallotherapeutics and targeted treatment of cancer.

scholarly journals Towards feedback-controlled nanomedicines for smart, adaptive delivery

2018 ◽  
Vol 244 (4) ◽  
pp. 283-293 ◽  
Author(s):  
Stephen J. Jones ◽  
Annette F. Taylor ◽  
Paul A Beales
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
The Body ◽  
Living Systems ◽  
Prolonged Release ◽  
Drug Bioavailability ◽  
Drug Release Profile ◽  
Chemical Systems

Nanomedicines for controlled drug release provide temporal and spatial regulation of drug bioavailability in the body. The timing of drug release is usually engineered either for slow gradual release over an extended period of time or for rapid release triggered by a specific change in its physicochemical environment. However, between these two extremes, there is the desirable possibility of adaptive nanomedicines that dynamically modulate drug release in tune with its changing environment. Adaptation and response through communication with its environment is a fundamental trait of living systems; therefore, the design of biomimetic nanomedicines through the approaches of bottom-up synthetic biology provides a viable route to this goal. This could enable drug delivery systems to optimize release in synchronicity with the body’s natural biological rhythms and the personalized physiological characteristics of the patient, e.g. their metabolic rate. Living systems achieve this responsiveness through feedback-controlled biochemical processes that regulate their functional outputs. Towards this goal of adaptive drug delivery systems, we review the general benefits of nanomedicine formulations, provide existing examples of experimental nanomedicines that encapsulate the metabolic function of enzymes, and give relevant examples of feedback-controlled chemical systems. These are the underpinning concepts that hold promise to be combined to form novel adaptive release systems. Furthermore, we motivate the advantages of adaptive release through chronobiological examples. By providing a brief review of these topics and an assessment of the state of the art, we aim to provide a useful resource to accelerate developments in this field. Impact statement The timing and rate of release of pharmaceuticals from advanced drug delivery systems is an important property that has received considerable attention in the scientific literature. Broadly, these mostly fall into two classes: controlled release with a prolonged release rate or triggered release where the drug is rapidly released in response to an environmental stimulus. This review aims to highlight the potential for developing adaptive release systems that more subtlety modulate the drug release profile through continuous communication with its environment facilitated through feedback control. By reviewing the key elements of this approach in one place (fundamental principles of nanomedicine, enzymatic nanoreactors for medical therapies and feedback-controlled chemical systems) and providing additional motivating case studies in the context of chronobiology, we hope to inspire innovative development of novel “chrononanomedicines.”

scholarly journals Correlation between Campanacci’s radiological classification of giant cell tumor of bone and expression of Cyclin D1 and PCNA

2017 ◽  
Vol 7 (1) ◽  
pp. 47
Author(s):  
Eréndira G. Estrada-Villaseñor ◽  
Hidalgo Bravo Alberto ◽  
C. Bandala ◽  
P. De la Garza-Montano ◽  
Reyes Medina Naxieli ◽  
...  
Keyword(s):  
Cyclin D1 ◽  
Giant Cell Tumor ◽  
Giant Cell ◽  
Descriptive Study ◽  
Cell Tumor ◽  
Giant Cell Tumors ◽  
Radiological Classification ◽  
Tumors Of Bone ◽  
Made In

Giant cell tumor of bone is considered by his behavior a benign but aggressive neoplasm. The objective of our study was to determine if there is a correlation between the Campanacci’s radiological classification of giant cell tumors of bone and the expression by immunohistochemistry of Cyclin D1 and proliferation cell nuclear antibody (PCNA). A retrospective and descriptive study was made. In total, there were 27 cases. All cases showed Cyclin D1 and PCNA positivity. Rho Spearman for Campanacci and Cyclin D1 expression was 0.06 and for Campanacci and PCNA was 0.418. We conclude that there is a positive correlation between PCNA expression in giant cell tumors of Bone and the Campanacci’s radiological classification II and III, butCyclin D1 expression was no related with radiologic features.

An Analysis of Systems of Classifying Mild Cognitive Impairment in Older People

2002 ◽  
Vol 36 (1) ◽  
pp. 133-140 ◽  
Author(s):  
Alexander Collie ◽  
Paul Maruff
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Older People ◽  
Classification Systems ◽  
Inclusion Criteria ◽  
Exclusion Criteria ◽  
Genetic Studies ◽  
The Past ◽  
Made In

Objective: Over the past two decades, a number of systems have been developed for the classification of cognitive and behavioural abnormalities in older people, in order that individuals at high risk of developing neurodegenerative disease, particularly Alzheimer's disease, may be identified well before the disease manifests clinically. This article critically examines the inclusion and exclusion criteria of a number of such classification systems, to determine the effect that variations in criterion may have on clinical, behavioural and neuroimaging outcomes reported from older people with mild cognitive impairment. Method: Qualitative review of the literature describing systems of classifying mild cognitive impairment, and outcomes from clinical, behavioural, neuroimaging and genetic studies of older people with mild cognitive impairment. Results: The exclusion and inclusion criteria for these classification systems vary markedly, as do the design of studies upon which the validity of these systems has been assessed. Minor changes to individual exclusion/inclusion criterion may result in substantial changes to estimates of the prevalence and clinical outcome of mild cognitive impairment, while inadequate experimental design may act to confound the interpretation of results. Conclusions: As a result of these factors, accurate and consistent estimates of the outcome of mild cognitive impairments in otherwise healthy older people are yet to be obtained. On the basis of this analysis of the literature, optimal criteria via which accurate classifications of mild cognitive impairment can be made in future are proposed.

scholarly journals Diatoms Green Nanotechnology for Biosilica-Based Drug Delivery Systems

Pharmaceutics ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 242 ◽  
Author(s):  
Monica Terracciano ◽  
Luca De Stefano ◽  
Ilaria Rea
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Low Cost ◽  
Release Kinetics ◽  
Drug Carrier ◽  
Drug Loading ◽  
Three Dimensional ◽  
Delivery Systems ◽  
Diatom Frustule ◽  
Artificial Environment

Diatom microalgae are the most outstanding natural source of porous silica. The diatom cell is enclosed in a three-dimensional (3-D) ordered nanopatterned silica cell wall, called frustule. The unique properties of the diatom frustule, including high specific surface area, thermal stability, biocompatibility, and tailorable surface chemistry, make diatoms really promising for biomedical applications. Moreover, they are easy to cultivate in an artificial environment and there is a large availability of diatom frustules as fossil material (diatomite) in several areas of the world. For all these reasons, diatoms are an intriguing alternative to synthetic materials for the development of low-cost drug delivery systems. This review article focuses on the possible use of diatom-derived silica as drug carrier systems. The functionalization strategies of diatom micro/nanoparticles for improving their biophysical properties, such as cellular internalization and drug loading/release kinetics, are described. In addition, the realization of hybrid diatom-based devices with advanced properties for theranostics and targeted or augmented drug delivery applications is also discussed.

Sign in / Sign up

Export Citation Format

Share Document