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1.
Gynecol Endocrinol ; 40(1): 2317268, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38468593

RESUMO

BACKGROUND: Vaginal dryness (VD) represents a significant concern affecting women across diverse life stages, encompassing both pre- and postmenopausal women at any age. Dyspareunia, defined by genital pain that can be experienced before, during, or after intercourse, is often associated with vaginal dryness. AIM: This study aimed to evaluate the effectiveness and safety of a water-based vaginal lubricant with hyaluronic acid to reduce sexual discomfort associated with vaginal dryness. METHODS: A prospective, multicenter, uncontrolled clinical investigation was conducted over a three-month period in women aged 18 years or older experiencing pain or difficulty during sexual intercourse for whom the use of a vaginal lubricant was recommended. RESULTS: Significant improvements were observed in the FSFI scores, indicating enhanced sexual function (p < .001). Vaginal dryness symptoms, including irritation, dryness, itching, and dyspareunia, significantly decreased after product use (p < .001). CLINICAL IMPLICATIONS: This study contributes to the limited scientific knowledge on the application of lubricants in the context of symptoms associated with VD. STRENGTHS & LIMITATIONS: In addition to the short study period, inherent limitations of the study design, and lack of placebo control, it is pertinent to acknowledge that some of the pros used in this study were not based on validated questionnaires. However, as far as we know, this study is the only one that analyzes well-being and sexual pleasure as results using a lubricant formulated with hyaluronic acid. CONCLUSION: This tested vaginal lubricant with hyaluronic acid has demonstrated efficacy in improving vaginal dryness and female sexual function, particularly in reducing pain and improving lubrication during sexual intercourse, and showed a favorable safety profile, with minimal and transient adverse events.


Assuntos
Dispareunia , Doenças Vaginais , Feminino , Humanos , Atrofia/patologia , Ácido Hialurônico/uso terapêutico , Lubrificantes/uso terapêutico , Dor/tratamento farmacológico , Estudos Prospectivos , Vagina/patologia , Doenças Vaginais/tratamento farmacológico , Doenças Vaginais/patologia , Água
2.
J Mech Behav Biomed Mater ; 152: 106439, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38325166

RESUMO

Osteoarthritis is a degenerative disease that is widely found in the elderly population, with a trend towards a younger age group in recent years. In the early stages of arthritis, patients are treated with hyaluronic acid injections and anti-inflammatory drugs. However, it has been found that hyaluronic acid can only play a supportive role and does not have a lubricating effect, and due to the absence of blood vessels, nerves, and lymphatic vessels in the articular cartilage, the oral anti-inflammatory drugs cannot reach the interface of the inflammatory joints adequately, and the drug utilisation rate is low. Herein, we designed and prepared a brush-like bionic lubricant for joint lubrication and drug loading. The poly(2-methyl-2-oxazoline) branched chain was grafted onto the hyaluronic acid main chain by ring-opening polymerisation and graft polymerisation to form a brush-like bionic lubricin containing multiple hydrophilic groups, which was self-assembled to encapsulate the drug by using its multi-branched special structure for drug loading. The friction behaviour tests on the articular cartilage surface showed that the prepared bionic lubricin has excellent lubrication effect, with a minimum friction coefficient of 0.036 close to the lubrication effect of natural synovial fluid, which is mainly due to the hydrophilic groups on its molecular chain that can adsorb the water molecules and form a hydration layer at the cartilage interface, which plays the role of hydration lubrication. In addition, in vitro drug release studies showed that the synthesised drug-loading biomimetic lubricin had a certain drug release capacity, and the maximum drug release rate could reach 77.8 % at 72 h. The synthesis of this bionic lubricant with dual functions of lubrication and drug release provides a new idea for the treatment of osteoarthritis.


Assuntos
Cartilagem Articular , Osteoartrite , Humanos , Idoso , Liberação Controlada de Fármacos , Biomimética , Ácido Hialurônico , Lubrificação , Osteoartrite/tratamento farmacológico , Anti-Inflamatórios , Lubrificantes
4.
Carbohydr Polym ; 330: 121821, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38368102

RESUMO

Restoration of the lubrication functions of articular cartilage is an effective treatment to alleviate the progression of osteoarthritis (OA). Herein, we fabricated chitosan-block-poly(sulfobetaine methacrylate) (CS-b-pSBMA) copolymer via a free radical polymerization of sulfobetaine methacrylate onto activated chitosan segment, structurally mimicking the lubricating biomolecules on cartilage. The successful copolymerization of CS-b-pSBMA was verified by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and 1H nuclear magnetic resonance. Friction test confirmed that the CS-b-pSBMA copolymer could achieve an excellent lubrication effect on artificial joint materials such as Ti6Al4V alloy with a coefficient of friction as low as 0.008, and on OA-simulated cartilage, better than the conventional lubricant hyaluronic acid, and the adsorption effect of lubricant on cartilage surface was proved by a fluorescence labeling experiment. In addition, CS-b-pSBMA lubricant possessed an outstanding stability, which can withstand enzymatic degradation and even a long-term storage up to 4 weeks. In vitro studies showed that CS-b-pSBMA lubricant had a favorable antibacterial activity and good biocompatibility. In vivo studies confirmed that the CS-b-pSBMA lubricant was stable and could alleviate the degradation process of cartilage in OA mice. This biomimetic lubricant is a promising articular joint lubricant for the treatment of OA and cartilage restoration.


Assuntos
Cartilagem Articular , Quitosana , Osteoartrite , Animais , Camundongos , Quitosana/farmacologia , Lubrificantes , Biomimética , Lubrificação , Polímeros/farmacologia
5.
Ther Deliv ; 15(4): 253-266, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38420754

RESUMO

Purpose: To explore 'magnesium myristate' for its dual functionality as a lubricant and binder in the formulation of tablets. Methods: Using (DoE), tablet formulations using magnesium myristate and conventional excipients (magnesium stearate and PVP K30) were developed by wet granulation technique. The prepared granules and formulated tablets were evaluated for pre- and post-compression parameters, respectively. Results: Magnesium myristate exhibited excellent flow properties. The optimized formulations containing magnesium myristate exhibited increased hardness and in vitro drug release in comparison to conventional excipients. f2 similarity index for in vitro drug release showed no significant variations with optimized formulations and with the marketed formulations. Conclusion: Magnesium myristate shows a promising replacement for conventional excipients as both a lubricant and binder in tablet formulation.


Assuntos
Excipientes , Magnésio , Miristatos , Lubrificantes , Comprimidos , Composição de Medicamentos , Solubilidade
6.
Int J Pharm ; 651: 123792, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38190952

RESUMO

The majority of tablets manufactured contain lubricants to reduce friction during ejection. However, especially for plastically deforming materials, e.g., microcrystalline cellulose (MCC), the internal addition of lubricants is known to reduce tablet tensile strength. This reduction is caused by the surface coverage by lubricant particles, the extent of which depends on both process and formulation parameters. Previously published models to predict the lubrication effect on mechanical strength do not account for changes in the excipient particle size. In this study, the impact of both lubricant concentration and mixing time on the tensile strength of tablets consisting of three different grades of MCC and four grades of magnesium stearate (MgSt) was evaluated. By taking into account the particle size of the applied excipients, a unifying relationship between the theoretically estimated surface coverage and compactibility reduction was identified. Evaluating the dispersion kinetics of MgSt as a function of time reveals a substantial impact of the initial surface coverage on the dispersion rate, while the minimal tensile strength was found to be comparable for the majority of formulations. In summary, the presented work extends the knowledge of lubricant dispersion and facilitates the reduction of necessary experiments during the development of new tablet formulations.


Assuntos
Celulose , Excipientes , Ácidos Esteáricos , Tamanho da Partícula , Excipientes/química , Ácidos Esteáricos/química , Comprimidos/química , Lubrificantes/química , Resistência à Tração
7.
PLoS One ; 19(1): e0295121, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38266033

RESUMO

OBJECTIVES: During the insertion of cochlear implant (CI) electrode arrays, forces occur which may cause trauma and poorer hearing outcomes. Unfortunately, research groups investigating factors influencing insertion forces come to contradicting results, especially regarding insertion speed. This study was conducted to investigate the origin of these contradicting results and to determine how different testing conditions influence experimental findings. METHODS: Repeated, automated insertions with three different FLEX28 CI electrode arrays (MED-EL, Innsbruck, Austria) were performed into a newly developed, anatomically correct and 3D-printed mean scala tympani phantom. The testing protocol for each electrode included variations in insertion speed (v = 0.1-2.0 mm/s) and lubrication (90%, 50%, and 10% liquid soap), resulting in 51 insertions per electrode array and a total of 153 insertions. RESULTS: The test setup and protocol allowed for repeatable insertions with only minimal change in the morphology of the insertion force profiles per testing condition. Strong but varying dependencies of the maximal insertion forces and work were found regarding both lubrication and speed: work-speed dependency is constant for the 10% lubricant, negative for the 50% lubricant and positive for the 90% lubricant. CONCLUSION: Our results can explain part of the contradicting results found within previous studies by translating interrelations known from lubricated rubber friction to the field of CI electrode array insertion. We show that the main driver behind measured bulk forces are most likely the generated friction forces, which are strongly dependent on insertion speed and lubrication. The employed test setup allows for conducting repeatable and comparable insertion studies, which can be recapitulated by other centers due to the detailed explanation of the test setup as well as the developed and freely available insertion phantom. This study hence represents another important step toward standardizing CI array insertion testing.


Assuntos
Implante Coclear , Implantes Cocleares , Lubrificação , Cóclea , Lubrificantes
8.
Hum Fertil (Camb) ; 27(1): 2285349, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38044638

RESUMO

Vaginal lubricants are commonly used to aid sexual pleasure and/or to help combat vaginal dryness and dyspareunia. Several studies have reported their impact on sperm function, however there are no published guidelines to help healthcare professionals and couples select a vaginal lubricant that is 'sperm-safe'. To address this, we conducted a literature search using both PubMed and Scopus to identify and appraise manuscripts that reported the impact of lubricants on sperm function. We did not restrict the literature search by year of publication, and we only included manuscripts that looked at the impact of vaginal lubricants on human sperm. The quality of the eligible studies was assessed using the Björndahl et al., (2016) checklist for semen analysis, as most of the studies reported the findings of a basic semen analysis. A total of 24 articles were eligible for analysis with a total of 35 vaginal lubricants (that were available to buy over the counter) being included, 2 of which studied the effect of vaginal lubricants on sperm function in vivo, and 22 being conducted in vitro. KY Jelly, PreSeed and Astroglide were most studied, with most manuscripts focussing on their impact on sperm motility. A paucity of data on most lubricants combined with methodological variations between studies and limited/no reporting on pregnancy outcomes means greater efforts are required before an evidence-based guideline can be published.


Assuntos
Lubrificantes , Motilidade dos Espermatozoides , Feminino , Humanos , Masculino , Lubrificantes/farmacologia , Sêmen , Espermatozoides , Análise do Sêmen
9.
J Chromatogr A ; 1713: 464525, 2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38000198

RESUMO

Lubricating oils help an internal combustion engine function effectively by reducing friction and wear on the engine's moving parts. They typically consist of petroleum-derived base oil and various additives to achieve the desired characteristics in automotive engine oils. Determination of aromatics and polar additives in the finished and used lubricating oils is not possible with existing methods hence their development is significant from the perspectives of environment and reuse/re-refining of used lubricating oils. This study reports the development of a new HPLC method to determine additives in the finished lubricating oils and/or polars in the used engine oils. The proposed method is simple, fast (runtime of 13 min), does not require sample pre-treatment, and exhibits high precision and superior limits of detection and quantification. The method demonstrated good linear response ranging from 0.1 to 30 mass for total aromatics and 0.1 to 20 % for additives. The method validation was carried out by analyzing brand-new commercial two and four-wheeler lubricants with used automotive lubricants. Based on the proposed method, the aromatics and additives concentration ranges in the studied finished lubricants were estimated between 0.20-1.70 % (mass) and 0.20-3.50 % (mass), respectively. Similarly, for used lubricants, the aromatics and additives were estimated to be 1.00-6.10 % and 0.60-2.40 % (mass), respectively.


Assuntos
Hidrocarbonetos Aromáticos , Petróleo , Cromatografia Líquida de Alta Pressão , Óleos , Petróleo/análise , Lubrificantes/análise , Lubrificantes/química
10.
Adv Mater ; 36(9): e2308972, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37917884

RESUMO

Slippery liquid-infused porous surfaces (SLIPS) have received widespread attention in the antifouling field. However, the reduction in antifouling performance caused by lubricant loss limits their application in marine antifouling. Herein, inspired by the skin of a poison dart frog which contains venom glands and mucus, a porous liquid (PL) based on ZIF-8 is prepared as a lubricant and injected into a silicone polyurethane (SPU) matrix to construct a new type of SLIPS for marine antifouling applications: the slippery porous-liquid-infused porous surface (SPIPS). The SPIPS consists of a responsive antifoulant-releasing switch between "defensive" and "offensive" antifouling modes to intelligently enhance the antifouling effect after lubricant loss. The SPIPS can adjust antifouling performance to meet the antifouling requirements under different light conditions. The wastage of antifoulants is reduced, thereby effectively maintaining the durability and service life of SLIPS materials. The SPIPS exhibits efficient lubricant self-replenishment, self-cleaning, anti-protein, anti-bacterial, anti-algal, and self-healing (97.48%) properties. Furthermore, it shows satisfactory 360-day antifouling performance in actual marine fields during boom seasons, demonstrating the longest antifouling lifespan in the field tests of reported SLIPS coatings. Hence, the SPIPS can effectively promote the development of SLIPS for neritic antifouling.


Assuntos
Incrustação Biológica , Animais , Incrustação Biológica/prevenção & controle , Porosidade , Lubrificantes , Poliuretanos
11.
J Mech Behav Biomed Mater ; 149: 106236, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37984287

RESUMO

Friction coefficient is considered as a measurement for clinical comfort of soft contact lenses. One of the main challenges in the tribology field is to evaluate the friction in soft materials such as soft contact lenses. In this work, we aim to evaluate the friction at the eyelid-lens contact using a new technique. This technique is based on a single-degree-of-freedom (SDOF) mass-spring system having a sliding contact. The experimental technique measures the free responses of the mechanical system. The friction is then evaluated from the damped free responses with a high accuracy. A variety of soft contact lenses are tested with some lubricants under many physiological conditions. The results are discussed and compared with those in the literature.


Assuntos
Lentes de Contato Hidrofílicas , Fricção , Lubrificantes
12.
ACS Appl Mater Interfaces ; 16(1): 1675-1687, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38127457

RESUMO

The ocular environment is crucial for a biological lubrication system. An unstable condition of tear film may cause a series of ocular diseases due to serious friction, such as dry eye syndrome, which has drawn extensive attention nowadays. In this study, an in vitro biocompatible superlubricity system, containing thermogelling copolymers (PCGA-PEG-PCGA) and slow-release lubricant (PEG 300/Tween 80), was constructed. First, the sol-gel transition temperature and gel strength of PCGA-PEG-PCGA were adjusted based on the ocular environment by regulating the length of PCGA blocks. Furthermore, the copolymer hydrogel exhibited a reliable slow-release property within 10 days and showed low cytotoxicity. Then, the superlubricity (coefficient of friction of approximately 0.005) was achieved with its released PEG 300/Tween 80 aqueous solution at the sliding velocity range of 1-100 mm s-1 and pressure range of 10-22 kPa. However, the lubrication behaviors varied, while PEG 300 chains and Tween 80 micelles were demonstrated to form a multilayer and a single layer adsorption structure on the sliding surface, respectively. On the whole, the composite lubrication systems, especially the one composed of Tween 80, showed excellent tribological properties owing to the stable slow-release and full hydration effects under ocular conditions, which hold great potential for improving ocular lubrication and maintaining human visual health.


Assuntos
Lubrificantes , Polissorbatos , Humanos , Lubrificantes/química , Polietilenoglicóis/química , Polímeros
13.
ACS Appl Mater Interfaces ; 15(48): 56433-56441, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-37975828

RESUMO

Tethered-liquid perfluorocarbons (TLPs) are a class of liquid-infused surfaces with the ability to reduce blood clot formation (thrombosis) on blood-contacting medical devices. TLP comprises a tethered perfluorocarbon (TP) infused with a liquid perfluorocarbon (LP); this LP must be retained to maintain the antithrombotic properties of the layer. However, the stability of the LP layer remains in question, particularly for medical devices under blood flow. In this study, the lubricant thickness is spatially mapped and quantified in situ through confocal dual-wavelength reflection interference contrast microscopy. TLP coatings prepared on glass substrates are exposed to the flow of 37% glycerol/water mixtures (v/v) or whole blood at a shear strain rate of around 2900 s-1 to mimic physiological conditions (similar to flow conditions found in coronary arteries). Excess lubricant (>2 µm film thickness) is removed upon commencement of flow. For untreated glass, the lubricant is completely depleted after 1 min of shear flow. However, on optimized TLP surfaces, nanoscale films of lubricants (thickness between 100 nm and 2 µm) are retained over many tens of minutes of flow. The nanoscale films conform to the underlying structure of the TP layer and are sufficient to prevent the adhesion of red blood cells and platelets.


Assuntos
Fluorocarbonos , Lubrificantes , Lubrificantes/farmacologia , Lubrificantes/química , Excipientes
14.
Sci Rep ; 13(1): 19833, 2023 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-37985688

RESUMO

Xerostomia, the subjective sensation of 'dry mouth' affecting at least 1 in 10 adults, predominantly elders, increases life-threatening infections, adversely impacting nutritional status and quality of life. A patented, microgel-reinforced hydrogel-based aqueous lubricant, prepared using either dairy or plant-based proteins, has been demonstrated to offer substantially enhanced lubricity comparable to real human saliva in in vitro experiments. Herein, we present the benchmarking of in vitro lubrication performance of this aqueous lubricant, both in its dairy and vegan formulation against a range of widely available and employed commercial saliva substitutes, latter classified based on their shear rheology into "liquids", "viscous liquids" and "gels", and also had varying extensional properties. Strikingly, the fabricated dairy-based aqueous lubricant offers up to 41-99% more effective boundary lubrication against liquids and viscous liquids, irrespective of topography of the tested dry mouth-mimicking tribological surfaces. Such high lubricity of the fabricated lubricants might be attributed to their limited real-time desorption (7%) from a dry-mouth mimicking hydrophobic surface unlike the tested commercial products including gels (23-58% desorption). This comprehensive benchmarking study therefore paves the way for employing these microgel-based aqueous lubricant formulations as a novel topical platform for dry mouth therapy.


Assuntos
Microgéis , Xerostomia , Adulto , Humanos , Idoso , Saliva/química , Hidrogéis , Lubrificantes/química , Benchmarking , Qualidade de Vida , Saliva Artificial , Xerostomia/terapia , Excipientes
15.
Eur J Pharm Biopharm ; 193: 262-273, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37944711

RESUMO

This study discusses the lubricant properties of magnesium stearate solid lipid nanoparticles (MgSt-SLN) and their effect on the tabletability, mechanical properties, disintegration, and acetaminophen-model dissolution time of microcrystalline cellulose (MCC) tablets prepared by direct compression. The behavior of MgSt-SLN was compared to reference material (RM) to identify advantages and drawbacks. The nanoprecipitation/ion exchange method was employed to prepare the MgSt-SLN. Particle size, zeta potential, specific surface area, morphology, and true density were measured to characterize the nanosystem. The MgSt-SLN particle sizes obtained were 240 ± 5 nm with a specific surface area of 12.2 m2/g. The MCC tablets with MgSt-SLN presented a reduction greater than 20 % in their ejection force, good tabletability, higher tensile strength, lower disintegration delay, and marked differences in acetaminophen dissolution when compared to the RM. The reduced particle size of the magnesium stearate seems to offer a promising technological advantage as an efficient lubricant process that does not affect the properties of tablets.


Assuntos
Acetaminofen , Lubrificantes , Lubrificantes/química , Ácidos Esteáricos/química , Excipientes/química , Comprimidos/química , Resistência à Tração
16.
Rev Bras Ginecol Obstet ; 45(11): e724-e728, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38029774

RESUMO

OBJECTIVE: To determine if the use of lubricating gel on the speculum during the cervicovaginal cytology examination interferes with the results obtained, as well as whether it reduces reported discomfort in patients. DATA SOURCES: A systematic review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, with a search in the Pubmed/Medline, Scielo, Cochrane Library, Embase databases of articles published between January 2011 and May 2022. The keywords used were cytology, speculum, lubricant, result, and pain. SELECTION OF STUDIES: The initial search resulted in 306 articles, of which were excluded three because they were duplicates, 257 after reading the title and abstract and 41 after reading the full text. Thus, five articles were selected for the study: four randomized clinical trials and one metanalysis. DATA COLLECTION: The selection of articles was performed by two investigators. The 5 selected articles were read in full and submitted to a comparative analysis. DATA SYNTHESIS: Screening through cervicovaginal cytology allows for early diagnosis and reduction of associated mortality, but the procedure can be associated with pain. A small amount of aqueous lubricating gel in the speculum can be used to reduce the discomfort associated with performing cervicovaginal cytology. CONCLUSION: The use of lubricating gel in the speculum does not seem to be associated with a change in the cytology result and reduces the discomfort associated with its insertion into the vagina.


OBJETIVO: Determinar se o uso de gel lubrificante no espéculo durante o exame de citologia cervicovaginal interfere com os resultados obtidos e se diminui o desconforto relatado por pacientes. FONTES DE DADOS: Foi realizada uma revisão sistemática segundo as recomendações do Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), com pesquisa nas bases de dados Pubmed/Medline, Scielo, Cochrane Library, Embase, de artigos publicados entre janeiro de 2011 e julho de 2022. Utilizaram-se as palavras-chave citologia, espéculo, lubrificante, resultado e dor. SELEçãO DOS ESTUDOS: A pesquisa inicial resultou em 306 artigos, dos quais foram excluídos três por se encontrarem duplicados, 257 após a leitura do título e do resumo e 41 após a leitura integral. Assim, foram selecionados cinco artigos para o estudo: quatro ensaios clínicos aleatorizados e uma metanálise. COLETA DE DADOS: A seleção dos artigos foi realizada por dois investigadores. Os cinco artigos selecionados foram lidos na íntegra e submetidos a uma análise comparativa. SíNTESE DOS DADOS: O rastreio através da citologia cervicovaginal permite um diagnóstico precoce e redução da mortalidade associada, mas a sua realização pode estar associada a dor. Uma pequena quantidade de gel lubrificante aquoso pode ser utilizada no espéculo para diminuir o desconforto associado à realização da citologia cervicovaginal. CONCLUSãO: A utilização de gel lubrificante não está associada a alteração do resultado da citologia e diminui o desconforto associado à sua introdução na vagina.


Assuntos
Lubrificantes , Dor , Feminino , Humanos , Dor/etiologia , Vagina
17.
Pharm Dev Technol ; 28(10): 992-999, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37938090

RESUMO

Punch sticking is a recurrent problem during the pharmaceutical tableting process. Powder moisture content plays a key role in the buildup of sticking; it evaporates due to increased tablet temperature, accumulates at the punch-tablet interface, and causes sticking through capillary force. This study investigated the effects of compaction pressure (CP), compaction speed (CS), and lubrication level (magnesium stearate (MgSt) ratio) on tablet surface temperature (TST) and tablet surface moisture content (TSMC). TST and TSMC were measured with an infrared thermal camera and near-infrared sensor, respectively. Microcrystalline cellulose was used as the tableting powder and MgSt as the lubricant. The low range of CS values (16-32 mm/s) considered in this study did not have significant effects on TST and TSMC. MgSt ratio had a significant positive effect on TST; this may be explained by the increase in powder blend effusivity with the addition of MgSt. However, MgSt ratio did not have a significant effect on TSMC. CP had a significant positive effect on both TST and TSMC. Increased CP induced higher heat generation through particle deformation and friction during the compaction phase, leading to increased TST. Furthermore, the water vapor diffusion rate through the powder bed might have increased due to the rise in thermal energy and led to further moisture accumulation at the tablet-punch interface, causing the significant positive effect of CP on TSMC. This result may explain the occurrence of sticking regardless of the CP applied during the tableting process.


Assuntos
Lubrificantes , Ácidos Esteáricos , Lubrificação , Pós/química , Temperatura , Lubrificantes/química , Comprimidos/química , Ácidos Esteáricos/química
18.
PLoS One ; 18(10): e0290346, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37856508

RESUMO

The artificial joint is one of the most effective methods to treat joint injuries. The service performance of artificial joints is gradually weakened because of the wear of artificial joints in actual service. In order to obtain the potential failure mechanism of the artificial joint in actual service, the study was carried out with the multiple factors that affect the service performance of the artificial joint. The experimental study was carried out on the change rule of mechanical behavior of the contact interface between the artificial joint of titanium alloy and cortical bone. The multi-factor is compression load, contact load, friction velocity, and lubrication environment, respectively. The results indicate that the friction coefficient, wear mass, and wear coefficient of Ti-6A1-4V titanium alloy decreased with the increasing of the compression load. The friction rate and the friction coefficient of Ti-6A1-4V titanium alloy decreased with the increasing of the contact load. The wear mass and friction coefficient of Ti-6A1-4V titanium alloy increased with the increasing of contact load. The lubrication effect is better with the increasing of lubricant concentration. Based on the observation of the SEM, the wear type influenced by compression load and friction rate is mainly abrasive wear and oxidation wear. The wear type influenced by contact load is mainly abrasive wear and adhesive wear. The wear type influenced by lubricants is mainly oxidation wear. When wear mass and wear coefficient are used as the criteria for evaluating friction and wear, the order of influential factors to friction and wear of Ti-6Al-4V titanium alloy plate is friction rate, compression load, contact load, and lubricant concentration. This research can provide a theoretical reference for the optimal manufacture of the artificial joint of titanium alloy and optimal rules of safe service conditions.


Assuntos
Osso Cortical , Titânio , Fricção , Ligas , Lubrificantes , Teste de Materiais , Propriedades de Superfície
19.
Cont Lens Anterior Eye ; 46(6): 102064, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37806847

RESUMO

PURPOSE: This study aimed to investigate the bacterial contamination of multi-use tear drops, gels, and ointments that patients use at home. METHOD: A total of 271 multi-use containers used by 168 patients were examined. Conjunctival culture samples were obtained from patients who used tear drops, gels, and ointments that were found to be contaminated. RESULTS: Bacterial contamination was detected in 33 (12.2 %) out of the 271 containers. The contamination rate was 7.9 % in tear drops, 11.7 % in gels, and 32 % in ointments. A statistically significant difference was found between the drops, gels, and ointment groups (P = 0.04). Bacterial contamination was detected in 25 (18.9 %) out of 132 collapsible tubes and 8 (5.8 %) out of 139 plastic bottles (P = 0.01). Important bacteria, including Pseudomonas stutzeri, Pseudomonas aeruginosa, Bacillus licheniformis, Paenibacillus pabuli, Proteus mirabilis, Pantoea agglomerans, Morganella morganii, Serratia marcescens, and Serratia liquefaciens, were detected. Mucorales spp. fungus was seen in a gel. Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus, and M. morganii were found in the conjunctival microbiota of three patients. CONCLUSION: The overall contamination rate of ocular lubricants was low (12.2%); however, a significant difference was found between the drops, gels, and ointments. The contamination rate was higher in gels and ointments than that in drops. The contamination rate was found to be increased in the collapsible tube. The use of ocular lubricants is safe; however, patients must be cautious when using multi-use tear drops, gels, and ointments to avoid contamination. Whenever possible, bottles should be preferred instead of collapsible tubes.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Humanos , Pomadas , Bactérias , Géis , Lubrificantes
20.
Pharm Res ; 40(10): 2479-2492, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37752367

RESUMO

INTRODUCTION: Tablets are commonly produced by internally adding particulate lubricants, which are known to possibly lower the mechanical strength of tablets. This reduction is caused by the coverage of matrix forming components by lubricant particles, resulting in decreased interparticulate interactions. The known incompatibilities with some active compounds of the predominantly used lubricant, magnesium stearate, call for the in-depth characterization of alternative lubricants. PURPOSE: Investigation of the dispersion behavior of five commonly applied pharmaceutical lubricants by mathematically modeling the dispersion kinetics for short and extended mixing times. METHODS: The dispersion behavior of five different pharmaceutical lubricants were examined by systematically varying lubricant concentration and mixing time of binary formulations and evaluating the kinetic of tensile strength reduction by theoretically estimating the surface coverage based on particle sizes. RESULTS: For short mixing times, a unifying relationship between compactibility reduction and theoretical surface coverage was identified. Subsequently, for extended mixing times, distinct differences in the shear strength and dispersion kinetics of the investigated lubricants were found. CONCLUSIONS: The lubricant particle size controls the tensile strength reduction if short mixing times are applied. For extended mixing times, the investigated lubricants can be divided into two groups in terms of dispersion kinetics. Possible underlying reasons are discussed in detail in order to enhance the general understanding of lubricant dispersions in tablet formulations.


Assuntos
Lubrificantes , Ácidos Esteáricos , Composição de Medicamentos , Resistência à Tração , Excipientes , Comprimidos
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