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1.
Proc Natl Acad Sci U S A ; 120(1): e2214143120, 2023 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-36574684

RESUMO

Due to its multifaceted impact in various applications, icing and ice dendrite growth has been the focus of numerous studies in the past. Dendrites on wetting (hydrophilic) and nonwetting (hydrophobic) surfaces are sharp, pointy, branching, and hairy. Here, we show a unique dendrite morphology on state-of-the-art micro/nanostructured oil-impregnated surfaces, which are commonly referred to as slippery liquid-infused porous surfaces or liquid-infused surfaces. Unlike the dendrites on traditional textured hydrophilic and hydrophobic surfaces, the dendrites on oil-impregnated surfaces are thick and lumpy without pattern. Our experiments show that the unique ice dendrite morphology on lubricant-infused surfaces is due to oil wicking into the porous dendritic network because of the capillary pressure imbalance between the surface texture and the dendrites. We characterized the shape complexity of the ice dendrites using fractal analysis. Experiments show that ice dendrites on textured oil-impregnated surfaces have lower fractal dimensions than those on traditional lotus leaf-inspired air-filled porous structures. Furthermore, we developed a regime map that can be used as a design guideline for micro/nanostructured oil-impregnated surfaces by capturing the complex effects of oil chemistry, oil viscosity, and wetting ridge volume on dendrite growth and morphology. The insights gained from this work inform strategies to reduce lubricant depletion, a major bottleneck for the transition of micro/nanostructured oil-impregnated surfaces from bench-top laboratory prototypes to industrial use. This work will assist the development of next-generation depletion-resistant lubricant-infused ice-repellent surfaces.


Assuntos
Excipientes , Gelo , Alimentos , Lubrificantes , Dendritos
2.
Biomacromolecules ; 25(6): 3554-3565, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38729918

RESUMO

Hydrogels are considered as a potential cartilage replacement material based on their structure being similar to natural cartilage, which are of great significance in repairing cartilage defects. However, it is difficult for the existing hydrogels to combine the high load bearing and low friction properties (37 °C) of cartilage through sample methods. Herein, we report a facile and new fabrication strategy to construct the PNIPAm/EYL hydrogel by using the macrophase separation of supersaturated N-isopropylacrylamide (NIPAm) monomer solution to promote the formation of liposomes from egg yolk lecithin (EYL) and asymmetric template method. The PNIPAm/EYL hydrogels possess a relatively high compressive strength (more than 12 MPa), fracture energy (9820 J/m2), good fatigue resistance, lubricating properties, and excellent biocompatibility. Compared with the PNIPAm hydrogel, the friction coefficient (COF 0.046) of PNIPAm/EYL hydrogel is reduced by 50%. More importantly, the COF (0.056) of PNIPAm/EYL hydrogel above lower critical solution temperature (LCST) does not increase significantly, exhibiting heat-tolerant lubricity. The finite element analysis further proves that PNIPAm/EYL hydrogel can effectively disperse the applied stress and dissipate energy under load conditions. This work not only provides new insights for the design of high-strength lubricating hydrogels but also lays a foundation for the treatment of cartilage injury as a substitute material.


Assuntos
Resinas Acrílicas , Hidrogéis , Hidrogéis/química , Resinas Acrílicas/química , Animais , Temperatura Alta , Lubrificantes/química , Cartilagem/química , Lecitinas/química , Força Compressiva , Lipossomos/química , Gema de Ovo/química , Materiais Biocompatíveis/química
3.
J Nanobiotechnology ; 22(1): 160, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589911

RESUMO

Dry eye disease (DED) is associated with ocular hyperosmolarity and inflammation. The marketed topical eye drops for DED treatment often lack bioavailability and precorneal residence time. In this study, we investigated catechol-functionalized polyzwitterion p(MPC-co-DMA), composed of 2-methacryloyloxyethyl phosphorylcholine (MPC) and dopamine methacrylamide (DMA) monomers, as potential topical nanotherapeutics for DED. The copolymers were synthesized via random free-radical copolymerization, producing different proportions of catecholic functionalization. All as-prepared polymer compositions displayed good ocular biocompatibility. At a feeding ratio of 1:1, p(MPC1-co-DMA1) can facilitate a robust mucoadhesion via Michael addition and/or Schiff base reaction, thus prolonging ocular residence time after 4 days of topical instillation. The hydration lubrication of MPC and radical-scavenging DMA endow the nano-agent to ease tear-film hyperosmolarity and corneal inflammation. A single dose of p(MPC1-co-DMA1) (1 mg/mL) after 4 days post-instillation can protect the cornea against reactive oxygen species, inhibiting cell apoptosis and the over-expression of pro-inflammatory factors (IL-6 and TNF-α). In clinical assessment, DED-induced rabbit eyes receiving p(MPC1-co-DMA1) could increase lacrimal fluid secretion by 5-fold higher than cyclosporine A. The catechol-functionalized polyzwitterion with enhanced lubricity, mucoadhesion, and anti-oxidation/anti-inflammation properties has shown high promise as a bioactive eye drop formulation for treating DED.


Assuntos
Antioxidantes , Lubrificantes , Animais , Coelhos , Antioxidantes/farmacologia , Materiais Biocompatíveis , Anti-Inflamatórios , Soluções Oftálmicas , Catecóis , Inflamação
4.
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
5.
AAPS PharmSciTech ; 25(6): 138, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890193

RESUMO

Unexpected cross-contamination by foreign components during the manufacturing and quality control of pharmaceutical products poses a serious threat to the stable supply of drugs and the safety of customers. In Japan, in 2020, a mix-up containing a sleeping drug went undetected by liquid chromatography during the final quality test because the test focused only on the main active pharmaceutical ingredient (API) and known impurities. In this study, we assessed the ability of a powder rheometer to analyze powder characteristics in detail to determine whether it can detect the influence of foreign APIs on powder flow. Aspirin, which was used as the host API, was combined with the guest APIs (acetaminophen from two manufacturers and albumin tannate) and subsequently subjected to shear and stability tests. The influence of known lubricants (magnesium stearate and leucine) on powder flow was also evaluated for standardized comparison. Using microscopic morphological analysis, the surface of the powder was observed to confirm physical interactions between the host and guest APIs. In most cases, the guest APIs were statistically detected due to characteristics such as their powder diameter, pre-milling, and cohesion properties. Furthermore, we evaluated the flowability of a formulation incorporating guest APIs for direct compression method along with additives such as microcrystalline cellulose, potato starch, and lactose. Even in the presence of several additives, the influence of the added guest APIs was successfully detected. In conclusion, powder rheometry is a promising method for ensuring stable product quality and reducing the risk of unforeseen cross-contamination by foreign APIs.


Assuntos
Contaminação de Medicamentos , Pós , Reologia , Pós/química , Reologia/métodos , Contaminação de Medicamentos/prevenção & controle , Excipientes/química , Acetaminofen/química , Celulose/química , Preparações Farmacêuticas/química , Controle de Qualidade , Aspirina/química , Química Farmacêutica/métodos , Lactose/química , Composição de Medicamentos/métodos , Lubrificantes/química , Princípios Ativos
6.
Nat Mater ; 21(8): 848-858, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35761059

RESUMO

Room-temperature ionic liquids and their mixtures with organic solvents as lubricants open a route to control lubricity at the nanoscale via electrical polarization of the sliding surfaces. Electronanotribology is an emerging field that has a potential to realize in situ control of friction-that is, turning the friction on and off on demand. However, fulfilling its promise needs more research. Here we provide an overview of this emerging research area, from its birth to the current state, reviewing the main achievements in non-equilibrium molecular dynamics simulations and experiments using atomic force microscopes and surface force apparatus. We also present a discussion of the challenges that need to be solved for future applications of electrotunable friction.


Assuntos
Líquidos Iônicos , Fricção , Lubrificantes , Simulação de Dinâmica Molecular
7.
Sex Transm Infect ; 99(7): 489-496, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37258272

RESUMO

OBJECTIVE: The vaginal metabolome is a significant factor in the vaginal microenvironment, and data are emerging on its independent role in urogenital health. Condomless vaginal intercourse and personal lubricant use are common practices that may affect the vaginal metabolome. The aim of the present study is to describe the associations between condomless intercourse and lubricant use on the vaginal metabolome. METHODS: This study used archived mid-vaginal swabs from a 10-week observational cohort of reproductive age women who self-collected samples and recorded behavioural diaries daily. Cases and controls were defined as participants who self-reported condomless vaginal intercourse with or without lubricant use, respectively. Samples were drawn prior to and following condomless vaginal intercourse. Twenty-two case participants were race/ethnicity matched to 22 control participants. Mid-vaginal swabs were subjected to 16S rRNA gene amplicon sequencing and untargeted ultrahigh performance liquid chromatography tandem mass spectroscopy metabolomics. Bayesian mixed-effects regression (unadjusted and adjusted for the vaginal microbiota) was used to evaluate differences in metabolite concentration associated with vaginal intercourse and lubricant use. RESULTS: Both condomless penile-vaginal intercourse and lubricant use were independently associated with higher (up to 8.3-fold) concentrations of metabolites indicative of epithelial damage (eg, sarcosine) and many host-produced antioxidants. Lubricant use was significantly associated with increases in lipids related to cellular damage, host-produced sphingolipids (antimicrobials), antioxidants and salicylate, a cooling agent common to lubricants, in a study design which controls for the independent effect of intercourse. Metabolites involved in oxidative stress and salicylate were strongly correlated with several molecular bacterial vaginosis-associated bacteria. CONCLUSIONS: This study provides important foundational data on how condomless vaginal-penile intercourse and lubricant use affect the vaginal metabolome and may affect the protective mechanisms in the vaginal microenvironment.


Assuntos
Lubrificantes , Metaboloma , Humanos , Feminino , RNA Ribossômico 16S , Teorema de Bayes , Salicilatos
8.
J Sex Med ; 20(4): 498-506, 2023 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-36781402

RESUMO

BACKGROUND: A range of personal lubricants with different formulations and subsequent properties are available for relief of discomfort associated with vaginal dryness; however, there are limited clinical data to support the efficacy and safety of many commercially available lubricants. AIM: To determine the effectiveness and safety of 5 water-based personal lubricants for the relief of intimate discomfort associated with vaginal dryness in pre- and postmenopausal women: 4 that were formulated to meet the World Health Organization (WHO) guidelines for osmolality and pH and 1 preexisting lubricant of higher osmolality and pH. METHODS: An open-label, parallel-design study was performed in women aged 18 to 65 years with mild-to-moderate vaginal dryness and dyspareunia. Participants were randomized to 1 of 5 lubricants (A-E) from 3 brands (Durex, KY, Queen V). They were instructed to use their allocated lubricants during vaginal intercourse at least once a week over a 4-week period. The Female Sexual Function Index (FSFI) measured sexual functioning after 4 weeks of use as an indicator of lubricant performance. OUTCOMES: The primary outcome was change from baseline in total FSFI score after 4 weeks of product use. RESULTS: A total of 174 women completed the study. The primary end point-a prespecified increase in FSFI ≥4 points from baseline after 4 weeks of use-was met by all 5 lubricants tested. A statistically significant improvement was observed across all 6 domains of the FSFI from baseline to 4 weeks of use with all 5 lubricants (P < .0001 for lubrication and pain reduction and P < .05 for all other domains). No serious adverse events occurred in the study, and the tolerance of all 5 lubricants was good/very good. CLINICAL IMPLICATIONS: The efficacy and safety of the tested lubricants are not compromised when formulated to meet the WHO criterion of osmolality ≤1200 mOsm/kg. The lubricants tested in this investigation can be used not only to relieve symptomatology of vaginal dryness and dyspareunia but also to enhance overall sexual satisfaction. STRENGTHS AND LIMITATIONS: This study provides clinical evidence for the efficacy and safety of 5 lubricants, including those formulated to meet WHO guidelines, in relieving symptoms of vaginal dryness and improving the overall sexual experience. The open-label design may have introduced bias into the study. CONCLUSION: All 5 lubricants, including those formulated to be compliant with guidelines on pH and osmolality, can be considered effective and well tolerated for the relief of discomfort associated with vaginal dryness.


Assuntos
Dispareunia , Doenças Vaginais , Feminino , Humanos , Dispareunia/etiologia , Dispareunia/tratamento farmacológico , Lubrificantes/uso terapêutico , Água , Coito , Doenças Vaginais/tratamento farmacológico , Vagina
9.
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
10.
Environ Res ; 231(Pt 2): 116120, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37182830

RESUMO

2,6-Di-tert-butyl-hydroxytotulene (BHT) is an additive commonly used in the manufacturing of lubricants to improve their antioxidant properties. However, in this study, we found that BHT affects the biodegradation of bio-lubricants by influencing the microbial community during the degradation of bio-lubricants. Specifically, BHT was found to reduce bacterial richness in activated sludge, but it increased the relative abundance of Actinobacteria (from 21.24% to 40.89%), Rhodococcus (from 17.15% to 31.25%), Dietzia (from 0.069% to 6.49%), and Aequorivita (from 0.90% to 1.85%). LEfSe analysis and co-occurrence network analysis suggested that Actinobacteria could be potential biomarkers and keystone taxa in microbial communities. Using the MetaCyc pathway database, the study found that BHT interfered with cellular biosynthetic processes. Additionally, the study also showed that mineral-lubricant base oils, which are difficult to degrade, significantly altered the diversity and composition of the microbiome. Overall, the findings demonstrate that BHT and mineral-lubricant base oils can substantially alter bacterial richness, structure, and function, potentially contributing to the difficulty in degrading lubricants. These findings have implications for the development of more biodegradable lubricants and the management of industrial waste containing lubricants.


Assuntos
Lubrificantes , Microbiota , Lubrificantes/química , Lubrificantes/metabolismo , Óleos , Antioxidantes , Minerais
11.
Climacteric ; 26(4): 292-295, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37105219

RESUMO

Vulvovaginal atrophy (VVA) is a chronic and progressive disease that affects sexuality and quality of life. VVA is preventable and treatable, but requires long-term and often sequential treatment. Sequential treatment consists of designing a strategy that uses one or more medications for a long enough time to achieve the desired benefits with minimal risk and maximum adherence. Currently available therapeutic options consist of topical over-the-counter products (including non-hormonal lubricants and moisturizers applied to the vagina), systemic hormone therapy and estrogens, and prescribed vaginal dehydroepiandrosterone (DHEA). In addition, we have a selective estrogen receptor modulator, ospemifene, and new energy-based treatments (laser and radiofrequency). There are clear differences between the treatments both in the mechanism of action and in the efficacy. Compliance is very low, and patients complain about the use of the vaginal route, often due to its low efficacy, or express fear of the long-term use of estrogens or the price of the treatments. We believe that, as a first option, and for physiological, preventive and efficacy reasons, we should consider the prescription of treatments that work on estrogen receptors. As a second option, there are vaginal moisturizers, which are effective on symptoms but do not prevent or improve conditions. Finally, techniques using heat, which although each time represent a clearer alternative, but on the other hand are the cost and the long-term safety data, give us a third option. Of course, we consider that vulvar moisturizers and lubricants can be used at any time.


Assuntos
Dispareunia , Pós-Menopausa , Feminino , Humanos , Qualidade de Vida , Estrogênios/uso terapêutico , Moduladores Seletivos de Receptor Estrogênico/uso terapêutico , Vagina/patologia , Vulva/patologia , Atrofia/tratamento farmacológico , Lubrificantes/uso terapêutico , Dispareunia/tratamento farmacológico
12.
Chem Pharm Bull (Tokyo) ; 71(9): 687-694, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37661374

RESUMO

Lactose is an excipient used extensively for bulking, diluting, and molding active pharmaceutical ingredients in tablet manufacturing. Particularly, granulated lactose (GL) intended for direct powder compression has distinct properties due to differences in manufacturing methods. It contributes to handling blended powders for tableting and tablet quality. In this study, we aimed to compare the functions of different forms of GL added as excipients during direct powder compression on the tablet properties and the effect of magnesium stearate (Mg-S) used as a lubricant on each type of GL. Different GL types obtained using different manufacturing methods (agitated granulation, GL-AG; spray-dried granulation, GL-SD; fluidized bed granulation, GL-FB) were blended with maize starch, low-substituted hydroxypropyl cellulose, and paracetamol in a V-type blender for 10 min. Mg-S was added at varying amounts (0.1, 1.0, and 2.0%) and blending times (5, 10, and 30 min) for the nine types of blended powders for tableting formulation. The powders were tableted, and the tablets were evaluated for weight and drug loading variations, tensile strength, friability, and disintegration time. When tablets with the same blending conditions were compared, the tensile strength and disintegration time were in the order of GL-FB > GL-SD > GL-AG. For each GL, we analyzed the effects of changes in the added amount of Mg-S and blending time using contour plots, evaluated the effects of blending conditions on tablet properties, and determined the target tablet properties. We investigated the optimization of the lubricant blending conditions to obtain suitable tablets.


Assuntos
Excipientes , Lactose , Pós , Lubrificantes , Comprimidos
13.
Ophthalmic Plast Reconstr Surg ; 39(6): 632-635, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37486341

RESUMO

PURPOSE: Surgical fires pose a substantial risk to patients and can cause significant injury, especially in oculofacial surgery. Ocular surface lubricants can potentially act as fuel for an operating room fire. We present an experimental analysis of the flammability of 9 commonly used ophthalmic lubricants under 4 ignition sources used in oculofacial surgery with and without supplemental oxygen. METHODS: The flammability of 9 ophthalmic lubricants were tested under various operating room conditions. Each lubricant was exposed to 4 different ignition sources: an open flame lighter, monopolar cautery, bipolar cautery, and hand-held high temperature cautery, and the response of the lubricant was recorded. The testing was conducted both in room air and with 6 L/minute of 100% oxygen directed at the lubricant through a nasal cannula. Any reaction in which there was ignition, sparking, smoking, or a transient or permanent change in appearance of the lubricant was deemed notable. RESULTS: Of the 9 lubricants tested, 4 displayed a reaction to the ignition source. Without supplemental oxygen, 100% petrolatum and neomycin-polysporin-bacitracin-hydrocortisone ointment produced some smoke when applied with the high temperature cautery. Notably, under both the conditions of no supplemental oxygen and with the addition of 6 L/minute of 100% oxygen, the carboxymethylcellulose drops and lidocaine jelly both conducted and sparked with the monopolar cautery leaving visible burn marks on the paper. CONCLUSIONS: The overall fire hazard posed by ocular surface lubricants is low. Some topical lubricants can conduct electricity from monopolar cautery, which could increase the risk of inadvertent electrical burns. Certain lubricants could potentially become a fuel source when used in combination with hand-held high temperature battery cautery. Bipolar cautery was not associated with either increased conductivity or flammability with any of the lubricants tested.


Assuntos
Queimaduras , Incêndios , Humanos , Salas Cirúrgicas , Queimaduras/etiologia , Oxigênio , Lubrificantes
14.
Vet Ophthalmol ; 26 Suppl 1: 81-88, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36749146

RESUMO

OBJECTIVE: Determine the precorneal retention time of five different ocular lubricants commonly used in dogs. ANIMALS STUDIED: Six healthy Beagle dogs (n = 12 eyes). PROCEDURES: Five ocular lubricants were studied: Artificial Tears Solution® (1.4% polyvinyl alcohol), I-Drop® Vet Plus (0.25% hyaluronate), Optixcare® Eye Lube Plus (0.25% hyaluronate), Systane® Ultra (0.4% polyethylene glycol 400 and 0.3% propylene glycol), and Artificial Tears Ointment® (mineral oil/white petrolatum). Each lubricant was mixed with 10% sodium fluorescein to achieve 1% fluorescein formulations. Following topical administration of 35 mg in each eye, tear fluid was collected with capillary tubes at selected times (0, 1, 5, 10, 20, 30, 40, 50, 60, 90, 120, 180 min) and fluorescein concentrations were measured with a computerized scanning ocular fluorophotometer. RESULTS: Tear fluorescence was significantly greater with Artificial Tears Ointment® compared with other lubricant formulations from 1 to 20 min post-administration. Median (range) precorneal retention times were significantly different among the 5 lubricants, ranging from 40 minutes (20-90 min) for Artificial Tears Ointment®, 35 min (20-90 min) for Systane® Ultra, 30 min (10-60 min) for I-Drop® Vet Plus, 25 min (10-60 min) for Optixcare® Eye Lube Plus, and 10 min (10-20 min) for Artificial Tears Solution®. Precorneal retention time was significantly lower for Artificial Tears Solution® compared with the other 4 formulations. CONCLUSIONS: This study established normative data for the retention time of common lubricants on the ocular surface of dogs, which may be used to guide clinicians with their choice of lubricant and frequency of administration.


Assuntos
Doenças do Cão , Síndromes do Olho Seco , Cães , Animais , Lubrificantes Oftálmicos , Fluorofotometria/veterinária , Síndromes do Olho Seco/veterinária , Soluções Oftálmicas , Pomadas , Lubrificantes , Lágrimas , Fluoresceínas
15.
Nano Lett ; 22(19): 7761-7767, 2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36170968

RESUMO

Interfacial water is a widespread lubricant down to the nanometer scale. We investigate the lubricities of molecularly thin H2O and D2O films confined between mica and graphene, via the relaxation of initially applied strain in graphene employing Raman spectroscopy. Surprisingly, the D2O films are at least 1 order of magnitude more lubricant than H2O films, despite the similar bulk viscosities of the two liquids. We propose a mechanism based on the known selective permeation of protons vs deuterons through graphene. Permeated protons and left behind hydroxides may form ion pairs clamping across the graphene sheet and thereby hindering the graphene from sliding on the water layer. This explains the lower lubricity but also the hindering diffusivity of the water layer, which yields a high effective viscosity in accordance with findings in dewetting experiments. Our work elucidates an unexpected effect and provides clues to the behavior of graphene on hydrous surfaces.


Assuntos
Grafite , Silicatos de Alumínio , Deutério , Grafite/química , Hidróxidos , Lubrificantes , Prótons , Água/química
16.
Molecules ; 29(1)2023 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-38202705

RESUMO

The lubricating properties of the lubricants were tested under boundary friction conditions; it was found that the surface-active additives had reduced the wear mark and thus the value of the Goz/40 parameter (limiting load of wear). The introduction of a surfactant containing amide compounds into the oils and greases was highly effective in slowing down the oxidation process. Lubricants containing mono-15 ([3-(N,N,N-dimethylbuthylamine)propyl]hexadecanamide chloride) and 15-4-15 (tetramethylene-bis [3-(N,N,N-dimethylamine)propyl]hexadecanamide) additives were characterised by higher oxidation stability compared to the unmodified lubricants. Both of the analysed substances showed bactericidal properties against Staphylococcus aureus and Salmonella enteritica. Tests of antibacterial activity in the lubricants with the addition of mono-15 and 15-4-15 confirmed that these lubricants can be considered bactericidal against Gram-positive and Gram-negative bacteria.


Assuntos
Antibacterianos , Lubrificantes , Lubrificantes/farmacologia , Antibacterianos/farmacologia , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Amidas/farmacologia
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.
Pharm Dev Technol ; 28(3-4): 363-370, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36987819

RESUMO

Mixing/blending is a crucial operation in the manufacturing of solid drug products in the pharmaceutical industry. Although usually described and controlled in specific steps, blending is also inherent to other operations such as the transference of materials and equipment feeding systems. This study aimed to investigate a simple and fast wettability testing procedure capable to foresee the potential over-blending effects of lubricants occurring during the manufacturing of solid dosage forms. An industrial batch blend was submitted to two mixing mechanisms studies (diffusion and shear) during increasing time periods, and the developed wettability testing procedure was applied to assess their impact on blend water uptake. Capsules filled with these blends were tested for dissolution and disintegration. The method was applied to capsules with known dissolution results manufactured at an industrial scale. Results demonstrated that processes inducing shear stress led to less permeable blends with consequent retardation on capsules dissolution of at least 35% in the tested timepoints and obtained study metrics above 500 s. Moreover, disintegration testing was not able to detect non-compliant dissolutions, while the proposed wettability testing procedure proved to be able to identify performance failures. Wettability results correlate the effect of mixing mechanisms to capsules dissolution performance, evidencing that this technique can be applied in the pharmaceutical industry to evaluate possible over-blending effects.


Assuntos
Química Farmacêutica , Lubrificantes , Molhabilidade , Química Farmacêutica/métodos , Solubilidade , Cápsulas , Comprimidos
19.
Tidsskr Nor Laegeforen ; 143(11)2023 08 15.
Artigo em Norueguês | MEDLINE | ID: mdl-37589352

RESUMO

BACKGROUND: In Norway, approximately 360 000 cervical screening samples were taken in 2020, of which 11 000 were registered as inadequate. We therefore wished to investigate doctors' knowledge of cervical sample-taking in the primary health service. MATERIAL AND METHOD: An anonymous survey on cervical sample-taking was sent by email to around 4 700 members of the Norwegian College of General Practice in September 2021. RESULTS: Of the 1 039 doctors who responded to the survey, 820 (79 %) reported that they always indicate the reason for taking the sample in the requisition form, and 898 (86 %) reported that they avoid taking a sample during menstruation. Only one in three doctors (343) correctly indicated the location of the squamocolumnar junction in postmenopausal women. In response to a question aimed at users of the ThinPrep method, which is particularly sensitive to sampling errors, 426 out of 697 (61 %) answered that they either avoid using a lubricant or use a water-based lubricant, while only 35 % of the doctors responded that they stop taking the sample if bleeding occurs. INTERPRETATION: The results show that although many doctors have satisfactory knowledge, a continuous focus on cervical sample-taking is essential. Correct sampling and knowledge of anatomical factors in postmenopausal women may be significant for reducing the number of inadequate samples.


Assuntos
Medicina Geral , Médicos de Atenção Primária , Manejo de Espécimes , Neoplasias do Colo do Útero , Feminino , Humanos , Detecção Precoce de Câncer , Lubrificantes , Atenção Primária à Saúde , Manejo de Espécimes/métodos , Manejo de Espécimes/normas , Conhecimentos, Atitudes e Prática em Saúde , Noruega
20.
Antimicrob Agents Chemother ; 66(11): e0081622, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36255254

RESUMO

Data to inform behaviorally congruent delivery of rectal microbicides as lubricants are scant. Dapivirine (DPV) is a nonnucleoside reverse transcriptase inhibitor which has been demonstrated to be well-tolerated and efficacious in multiple clinical trials when used in a vaginal ring formulation. DPV gel administered rectally with an applicator was found to be well-tolerated in a phase 1 clinical trial. MTN-033, a single site, open label, sequence randomized, crossover study, enrolled HIV-negative men to receive 0.05% DPV gel intrarectally using an applicator (2.5 g) and self-administered on an artificial phallus as lubricant (up to 10 g). The study evaluated the pharmacokinetics (in plasma, rectal fluid, and mucosal rectal tissue), safety, acceptability, and pharmacodynamics of DPV gel when applied rectally. Statistical comparisons between methods of application were performed using mixed effects models or Wilcoxon's signed rank tests. Sixteen participants used DPV gel by applicator and 15/16 participants used gel as lubricant (mean, 1.8 g; SD, 0.8). DPV plasma AUC0-24h after use as lubricant was estimated to be 0.41 times the AUC0-24h (95% CI 0.24, 0.88) after use with applicator. While DPV was quantifiable in plasma and luminal fluid, it was not quantifiable in tissue for both applicator and as lubricant administration. No related adverse events (AE) were reported, and 15/15 participants felt the gel was easy to use. Evidence of local delivery and systemic absorption of DPV when dosed as an anal lubricant supports the feasibility and potential for development of lubricant-delivered rectal microbicides. There were no safety concerns associated with use of DPV gel and participants reported finding it easy to use. However, lower DPV exposure in plasma and lack of quantifiable DPV in rectal tissue indicate that higher potency, concentration, and longer half-life antiretrovirals with optimized formulations will be needed to achieve protective tissue concentrations.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Humanos , Masculino , Feminino , Lubrificantes/uso terapêutico , Estudos Cross-Over , Pirimidinas/farmacocinética , Inibidores da Transcriptase Reversa/uso terapêutico , Géis , Infecções por HIV/tratamento farmacológico , Infecções por HIV/prevenção & controle
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