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1.
Molecules ; 26(21)2021 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-34771027

RESUMEN

An extension of neo-Darwinism, termed preassembly, states that genetic material required for many complex traits, such as echolocation, was present long before emergence of the traits. Assembly of genes and gene segments had occurred over protracted time-periods within large libraries of non-coding genes. Epigenetic factors ultimately promoted transfers from noncoding to coding genes, leading to abrupt formation of the trait via de novo genes. This preassembly model explains many observations that to this present day still puzzle biologists: formation of super-complexity in the absence of multiple fossil precursors, as with bat echolocation and flowering plants; major genetic and physical alterations occurring in just a few thousand years, as with housecat evolution; lack of precursors preceding lush periods of species expansion, as in the Cambrian explosion; and evolution of costly traits that exceed their need during evolutionary times, as with human intelligence. What follows in this paper is a mechanism that is not meant to supplant neo-Darwinism; instead, preassembly aims to supplement current ideas when complexity issues leave them struggling.


Asunto(s)
Evolución Molecular , Selección Genética/genética , Animales , Humanos , Filogenia
2.
Oncology ; 98(8): 520-527, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32369814

RESUMEN

In this review, human methotrexate dosing regimens, as well as their relationship to data from in vitro cell culture and in vivo animal and human studies, are discussed. Low-dose, intermediate-dose, and high-dose therapies are covered. Since in vitro and in vivo screenings of potential cancer drugs are commonplace in the development of cancer chemotherapy, comparisons of the three criteria for effectiveness are important.


Asunto(s)
Antimetabolitos Antineoplásicos/administración & dosificación , Antimetabolitos Antineoplásicos/uso terapéutico , Metotrexato/administración & dosificación , Metotrexato/uso terapéutico , Neoplasias/tratamiento farmacológico , Adolescente , Adulto , Animales , Niño , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Humanos , Masculino , Metotrexato/química , Neoplasias/patología
3.
Saudi Pharm J ; 28(8): 994-1003, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32792844

RESUMEN

Rheumatoid arthritis (RA) is an autoimmune disease associated with severe joint pain. Herein, we report lornoxicam loaded cellulosic microsponge gel formulation with sustained anti-inflammatory effects that are required to manage arthritic pain. The microsponges were formulated using quasi emulsion-solvent diffusion method employing four different surfactant systems, namely polyvinyl alcohol (PVA), Tween80, Gelucire 48/16 and Gelucire 50/13. All the lornoxicam loaded microsponge formulations were extensively characterized with a variety of analytical tools. The optimized microsponge formulation was then converted into gel formulation. The lornoxicam loaded microsponge gel formulation had adequate viscosity and sufficient pharmaceutical properties as confirmed by the texture analysis and the drug release followed Super case II transport. It is noteworthy that we described the preparation of a new cellulosic polymers based microsponge system for delivery of lornoxicam to provide quick as well as lasting (sustained) anti-inflammatory effects in rats using carrageenan induced rat paw edema model. We were able to demonstrate a 72% reduction in inflammation within 4 h using the optimize transdermal gel formulation utilizing Transcutol P as permeation enhancer and with the aid of skin micro-piercing by microneedles, hence, demonstrating the potential of this microsponge gel formulation in arthritis management.

4.
Med Princ Pract ; 28(1): 91-95, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30355921

RESUMEN

OBJECTIVE: To present a case of Hashimoto encephalopathy as a complication of autoimmune thyroiditis. CLINICAL PRESENTATION AND INTERVENTION: A previously healthy 56-year-old female presented with rapidly progressive cognitive decline and visual hallucinations. Being a diagnosis of exclusion, Hashimoto encephalopathy required an extensive laboratory and diagnostic workup, which was done over the course of a 15-day hospitalization. The patient recovered after initial treatment with intravenous methylprednisolone and was then switched to prednisone p.o. CONCLUSION: This case report illustrates the importance of awareness for Hashimoto encephalopathy, as it remains one of the few easily treatable and reversible causes of rapid cognitive decline.


Asunto(s)
Encefalitis/complicaciones , Enfermedad de Hashimoto/complicaciones , Tiroiditis Autoinmune/complicaciones , Antiinflamatorios/uso terapéutico , Encefalitis/diagnóstico , Encefalitis/tratamiento farmacológico , Femenino , Enfermedad de Hashimoto/diagnóstico , Enfermedad de Hashimoto/tratamiento farmacológico , Humanos , Metilprednisolona/uso terapéutico , Persona de Mediana Edad , Resultado del Tratamiento
5.
Med Princ Pract ; 27(6): 501-507, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30173215

RESUMEN

Rheumatoid arthritis (RA) is a chronic, inflammatory, systemic autoimmune disease, affecting the joints with varying severity among patients. The risk factors include age, gender, genetics, and environmental exposure (cigarette smoking, air pollutants, and occupational). Many complications can follow, such as permanent joint damage requiring arthroplasty, rheumatoid vasculitis, and Felty syndrome requiring splenectomy if it remains unaddressed. As there is no cure for RA, the treatment goals are to reduce the pain and stop/slow further damage. Here, we present a brief summary of various past and present treatment modalities to address the complications associated with RA.


Asunto(s)
Artritis Reumatoide/tratamiento farmacológico , Corticoesteroides/efectos adversos , Corticoesteroides/uso terapéutico , Analgésicos Opioides/uso terapéutico , Antiinflamatorios no Esteroideos/efectos adversos , Antiinflamatorios no Esteroideos/uso terapéutico , Anticuerpos Monoclonales Humanizados/uso terapéutico , Antirreumáticos/efectos adversos , Antirreumáticos/uso terapéutico , Artritis Reumatoide/complicaciones , Artritis Reumatoide/cirugía , Humanos , Inmunosupresores/uso terapéutico , Proteína Antagonista del Receptor de Interleucina 1/uso terapéutico , Leflunamida/uso terapéutico , Modalidades de Fisioterapia , Factores de Riesgo , Factor de Necrosis Tumoral alfa/uso terapéutico
6.
Saudi Pharm J ; 26(1): 64-70, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29379334

RESUMEN

The development of nanoparticle-based drug formulations has yielded the opportunities to address and treat challenging diseases. Nanoparticles vary in size but are generally ranging from 100 to 500 nm. Through the manipulation of size, surface characteristics and material used, the nanoparticles can be developed into smart systems, encasing therapeutic and imaging agents as well as bearing stealth property. Further, these systems can deliver drug to specific tissues and provide controlled release therapy. This targeted and sustained drug delivery decreases the drug related toxicity and increase patient's compliance with less frequent dosing. Nanotechnology has proven beneficial in the treatment of cancer, AIDS and many other disease, also providing advancement in diagnostic testing.

7.
BMC Complement Altern Med ; 14: 226, 2014 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-25002129

RESUMEN

BACKGROUND: The essential oil (EO) of Artemisia vulgaris L. has been traditionally used worldwide for treating a large number of diseases. Although major components in A. vulgaris EO have been shown to inhibit growth of different cancer cells, as pure compounds or part of other plants extracted oil, no information is known about its anti-proliferative activities. Therefore, the current investigation has evaluated the toxicity of the plant extracted oil from buds (AVO-b) and leaves (AVO-l) and characterized their growth inhibitory effects on cancer cells. METHODS: AVO-b and AVO-l from A. vulgaris L. were extracted by hydrodistillation, and their effect on the viability of human HL-60 promyelocytic leukemia and various other cancer cell lines was tested using MTT assay. Flow cytometric analysis of apoptosis, DNA fragmentation assay, caspases enzymatic activities and Western blotting were used to determine the apoptotic pathway triggered by their action on HL-60 cells. RESULTS: Low concentrations of AVO-b and AVO-l inhibited the growth of HL-60 cells in a dose- and time-dependent manner. Employing flow cytometric, DNA fragmentation and caspase activation analyses, demonstrated that the cytotoxic effect of the oils is mediated by a caspase-dependent apoptosis. Kinetic studies in the presence and absence specific caspase inhibitors showed that activation of caspase-8 was dependent and subsequent to the activation of caspases-9 and -3. In addition, the essential oil caused a disruption of the mitochondrial transmembrane potential (ΔΨm), increased the release of cytochrome c to the cytosol, and altered the expression of certain members of Bcl-2 family (Bcl-2, Bax and Bid), Apaf-1 and XIAP. Interestingly, low doses of AVO-b and AVO-1 also induced apoptosis in various cancer cell lines, but not in noncancerous cells. CONCLUSIONS: The results demonstrate that the EO-induced apoptosis in HL-60 cells is mediated by caspase-dependent pathways, involving caspases-3, -9, and -8, which are initiated by Bcl-2/Bax/Bid-dependent loss of ΔΨm leading to release of cytochrome c to the cytoplasm to activate the caspase cascade. The finding that AVO-b and AVO-l are more efficient to induce apoptosis in different cancer cell lines than noncancerous cells, suggests that A. vulgaris might be a promising source for new anticancer agents.


Asunto(s)
Apoptosis/efectos de los fármacos , Artemisia/química , Mitocondrias/efectos de los fármacos , Aceites Volátiles/farmacología , Caspasas/metabolismo , Supervivencia Celular/efectos de los fármacos , Citocromos c/metabolismo , Células HL-60 , Humanos , Aceites Volátiles/química , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo
8.
Prog Mol Biol Transl Sci ; 202: 127-154, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38237984

RESUMEN

This chapter provides an overview of the innate immune response to SARS-CoV-2, focusing on the recognition, activation, and evasion strategies employed by the virus. The innate immune system plays a crucial role in the early defense against viral infections, and understanding its response to SARS-CoV-2 is essential for developing effective therapeutic approaches. The chapter begins by explaining the basics of the innate immune system, including its components and salient features. It discusses the various pattern recognition receptors involved in recognizing SARS-CoV-2, such as toll-like receptors, RIG-I-like receptors, NOD-like receptors, and other cytosolic sensors. The binding and entry of the virus into host cells and subsequent activation of innate immune cells, including neutrophils, monocytes, macrophages, dendritic cells, NK cells, and ILCs, are explored. Furthermore, the secretion of key cytokines and chemokines, including type I interferons, IL-6, IL-17, and TNF-alpha, is discussed as part of the innate immune response. The concept of PANoptosis, involving programmed cell death mechanisms, is introduced as a significant aspect of the response to SARS-CoV-2. The chapter also addresses the innate immune evasion strategies employed by SARS-CoV-2, which allow the virus to evade or subvert the host immune response, contributing to viral persistence. Understanding these strategies is crucial for developing targeted therapies against the virus.


Asunto(s)
COVID-19 , Virosis , Humanos , SARS-CoV-2 , Inmunidad Innata , Citocinas
9.
Cureus ; 16(6): e62081, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38868548

RESUMEN

A patient with multiple comorbidities and an eight-year history of tracheostomy was being treated for tracheitis. At this point, she became incapable of using regular speaking valves, and multiple attempts to reintroduce the speaking valve failed. A Ferrer adjustable speaking valve (FASV) was designed with gradations of outflow closure, allowing air to go through the vocal cords for phonation. The FASV was offered to her through the compassionate use program at the FDA. At 20% initial closure, the patient was able to tolerate the valve and was advanced to 50% closure, at which point she could phonate partially. The use of the valve was terminated at the time of her transfer, 23 days after the initiation of use. This suggests the safety and possible efficacy of using an adjustable speaking valve earlier than regular valves, allowing patients to communicate earlier and further exercise their diaphragms.

10.
J Clin Transl Res ; 9(3): 175-181, 2023 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-37275580

RESUMEN

Background: Although cardiovascular disease (CVD) has markedly declined since the early 1960s due to medical advances and better management, this condition persists as the most critical and preventable cause of death in the US. For that reason, the identification and application of more sensitive, specific, validated, and noninvasive biomarkers of cardiovascular functioning in the primary care setting for the early identification of CVD risk at the subclinical level are warranted. Aim: The goal of the present review is twofold: first, to familiarize the primary care practitioner with noninvasive aortic hemodynamic parameters, including how these could be integrated into primary care services and patient management, and second, to propose a model for earlier detection of CVD based on the noninvasive hemodynamic parameters in the primary care setting. Relevance for Patients: Implementation of noninvasive hemodynamic monitoring in a primary care setting could help in the identification of heart disease risk at the early onset thus preventing the need for expensive treatment or death at later stages.

11.
J Endocr Soc ; 7(10): bvad112, 2023 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-37693687

RESUMEN

Context: Ketogenic diet has recently made a comeback as a part of lifestyle and dietary modifications in patients with polycystic ovary syndrome (PCOS). Despite studies suggesting its beneficial effects in reversing hormonal imbalance in women with PCOS, evidence has been patchy and derived from small populations under varying conditions. Objective: To pool evidence from clinical trials to study the effects of ketogenic diet on reproductive hormones (LH/FSH ratio, free testosterone, serum progesterone) and observe evidence of weight change. Methods: PubMed, ScienceDirect, Scopus, and Web of Science core collection were searched for clinical trials evaluating the effects of ketogenic diet in established PCOS women consistent with the Rotterdam classification. Single- or double-arm studies that included an outcome of interest were included. Two investigators worked independently to screen potential articles and a designated investigator extracted data on study characteristics and evaluated the outcomes. Data were pooled using a random-effects model. The quality of selected studies was assessed using the Cochrane Risk of Bias Tool. Results: Following ≥45 days of intervention with ketogenic diet among women with PCOS, significant improvement was observed in reproductive hormone levels, with reduced LH/FSH ratio (d -0.851; 95% CI -1.015, -0.686; P < .001), reduced serum free testosterone (d -0.223; 95% CI -0.328, -0.119; P  < .001), and an increased in serum sex hormone binding globulin (SHBG) (d 9.086; 95% CI 3.379, 14.792; P = .002). Significant weight loss was unanimously observed in all included studies (d -11.56; 95% CI -14.97, -8.15; P < .001). Conclusion: Short-term ketogenic diet potentially improved hormonal imbalances commonly associated with PCOS.

12.
J Thorac Dis ; 15(11): 6265-6278, 2023 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-38090319

RESUMEN

Background: N7-methylguanosine (m7G) is an important posttranscriptional modification affecting mRNA and tRNA functions and stability. The genes regulating the m7G process have been previously found involved in the carcinogenesis process. We aimed to analyze the role of m7G-related genes as potential prognostic markers for lung squamous cell carcinoma (LSCC). Methods: Twenty-nine m7G-related genes were selected for the analysis in the LSCC cohort of the Cancer Genome Atlas (TCGA). Univariate, multivariate, and Kaplan-Meier analyses were used to evaluate the predictive value of risk model developed with m7G signature for overall survival (OS).. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of differentially expressed genes (DEGs) were performed for high- and low-risk LSCC groups. Results: We identified 17 differentially expressed m7G methylation-related genes in LSCC versus normal tissues. The expression of five m7G-related genes (EIF3D, LSM1, NCBP2, NUDT10, and NUDT11) was identified as an independent prognostic marker for OS in LSCC patients. A risk model with these five m7G-related genes predicted 2-, and 3-year survival rates of 0.623 and 0.626, respectively. The risk score significantly correlated with OS: LSCC patients with a higher risk score had shorter OS (P<0.01) and it was associated with lower immune response (P<0.01). Conclusions: We developed a novel m7G-related gene signature that can be of great utility to predict the prognosis for patients with LSCC.

13.
Bull Environ Contam Toxicol ; 89(4): 699-703, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22936015

RESUMEN

Transport processes are the hallmark of functioning kidney. Various nephrotoxicants disrupt the transport processes to manifest nephrotoxicity. Of several nephrotoxicants, mercuric chloride (HgCl(2)) depletes the reduced glutathione (GSH) in kidney and has been observed to affect the in vitro p-aminohippurate (PAH) transport by basolateral (BL) membrane vesicles. The role of renal nonprotein sulfhydryls such as, reduced GSH has been demonstrated to affect the PAH transport by BL membrane vesicles. The role of protein sulfhydryls in transport process of PAH by BL membrane is not known. Due to mercury mediated effects on sulfhydryls, the effects of protein-sulfhydryls (-SH) modifying reagents in the current study were investigated on PAH transport by BL membrane. It was observed that modification of -SH by p-chloromercuribenzoate sulphate (pCMBS), and mercuric chloride (HgCl(2)) decreased while recovering the protein -SH with dithiothreitol treatment provided protection against the effects of pCMBS, and HgCl(2) on PAH transport by BL membrane vesicles.


Asunto(s)
Sustancias Peligrosas/toxicidad , Riñón/efectos de los fármacos , Compuestos de Sulfhidrilo/toxicidad , Animales , Transporte Biológico/efectos de los fármacos , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Glutatión/metabolismo , Riñón/metabolismo , Riñón/ultraestructura , Ratas , Ácido p-Aminohipúrico/metabolismo
14.
Biomolecules ; 12(10)2022 10 09.
Artículo en Inglés | MEDLINE | ID: mdl-36291651

RESUMEN

Infectious diseases have been a threat to human health globally. The relentless efforts and research have enabled us to overcome most of the diseases through the use of antiviral and antibiotic agents discovered and employed. Unfortunately, the microorganisms have the capability to adapt and mutate over time and antibiotic and antiviral resistance ensues. There are many challenges in treating infections such as failure of the microorganisms to respond to the therapeutic agents, which has led to more chronic infections, complications, and preventable loss of life. Thus, a multidisciplinary approach and collaboration is warranted to create more potent, effective, and versatile therapies to prevent and eradicate the old and newly emerging diseases. In the recent past, natural medicine has proven its effectiveness against various illnesses. Most of the pharmaceutical agents currently used can trace their origin to the natural products in one way, shape, or form. The full potential of natural products is yet to be realized, as numerous natural resources have not been explored and analyzed. This merits continuous support in research and analysis of ancient treatment systems to explore their full potential and employ them as an alternative or principal therapy.


Asunto(s)
Antivirales , Productos Biológicos , Humanos , Antivirales/farmacología , Antivirales/uso terapéutico , Medicina Tradicional , Productos Biológicos/uso terapéutico , Antibacterianos/uso terapéutico , Preparaciones Farmacéuticas
15.
Artículo en Inglés | MEDLINE | ID: mdl-35652393

RESUMEN

Chlorpheniramine Maleate (CPM), also known as chlorphenamine, is a potent alkylamine first-generation H1 antihistamine that has been around since the 1950s. CPM is a widely popular drug commonly used to treat allergic conditions, given its antihistamine properties. Although mainly used in over-the-counter treatment for cough and colds, various studies discuss a wide range of CPM's clinical uses, such as treating asthma, plasma cell gingivitis, chronic urticaria, depression, among others. This antihistamine is usually taken orally; however, intravenous, intramuscular, and subcutaneous routes have been documented. Intranasal routes have recently been explored, especially due to its antiviral properties against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Accordingly, given CPM's extensive medical and safety profile, the present review explores this versatile drug's current and potential clinical applications. Although it is widely used mainly for treating common colds and aforementioned allergic conditions, it can be concluded that CPM can be considered to be used for other clinical indications. The repurposing of CPM for other clinical indications such as COVID-19 needs to be further explored through more extensive studies.

16.
Ann Transl Med ; 10(7): 420, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35530953

RESUMEN

Background: The hospitalization for asthma exacerbation has varied with seasons, however, the underlying weather reasons have not been fully explored yet. This study is aimed to explore the effect of weather factors on increased number of hospitalization due to worsening of asthma symptoms. This will provide more information to the relevant authorities to allocate appropriate medical resources as per the weather conditions in Qingdao, China. Methods: All adult patients admitted for asthma exacerbation from 1 January, 2017 to 31 December, 2019 were enrolled from 13 main hospitals of Qingdao. The clinical data, including age, sex, smoking history, etc., were collected from the electronic medical record (EMR) systems. The hourly air quality of Qingdao from 2017-2019, including the air quality index (AQI), PM2.5 and PM10, was obtained from the China National Environmental Monitoring Centre. All these parameters during 2017-2019 were compared monthly. For meteorological data, the monthly horizontal wind at 850 hPa and vertical velocity at 500 hPa during 1960-2020 were obtained from National Center for Environmental Prediction (NCEP) and the National Center for Atmospheric Research (NCAR) global reanalysis dataset. The correlation analysis was applied to determine the association between asthma hospitalizations and the environmental factors, including atmospheric pressure, humidity, vertical visibility, and etc., monthly. Results: In all, 10,549 asthmatic inpatients (45.7% males, 54.3% females) were included in the study. The inpatients number for asthma exacerbation had a plateau lasting from March to June of 2019, accompanied with high PM2.5 and PM10, as well as bad air quality from January to March of 2019, potentially governed by the El Niño event in 2018. However, there was no significance correlation between the number of asthma hospitalizations and the average value of all environmental factors. Conclusions: The high rate of hospitalization for asthma exacerbation in Qingdao during the spring of 2019 was associated with the unfavorable weather conditions, which might be linked to the atmospheric circulation in East Asia.

17.
Toxicol Rep ; 9: 521-533, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35371924

RESUMEN

The incidence of hypertension with diabetes mellitus (DM) as a co-morbid condition is on the rise worldwide. In 2000, an estimated 972 million adults had hypertension, which is predicted to grow to 1.56 billion by 2025. Hypertension often leads to diabetes mellitus that strongly puts the patients at an increased risk of cardiovascular, kidney, and/or atherosclerotic diseases. Hypertension has been identified as a major risk factor for the development of diabetes; patients with hypertension are at two-to-three-fold higher risk of developing diabetes than patients with normal blood pressure (BP). Causes for the increase in hypertension and diabetes are not well understood, environmental factors (e.g., exposure to environmental toxicants like heavy metals, organic solvents, pesticides, alcohol, and urban lifestyle) have been postulated as one of the reasons contributing to hypertension and cardiovascular diseases (CVD). The mechanism of action(s) of these toxicants in developing hypertension and CVDs is not well defined. Research studies have linked hypertension with the chronic consumption of alcohol and exposure to metals like lead, mercury, and arsenic have also been linked to hypertension and CVD. Workers chronically exposed to styrene have a higher incidence of CVD. Recent studies have demonstrated that exposure to particulate matter (PM) in diesel exhaust and urban air contributes to increased CVD and mortality. In this review, we have imparted the role of environmental toxicants such as heavy metals, organic pollutants, PM, alcohol, and some drugs in hypertension and CVD along with possible mechanisms and limitations in extrapolating animal data to humans.

18.
J Am Chem Soc ; 133(9): 2881-3, 2011 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-21322595

RESUMEN

Cryo-TEM and NaCl-leakage experiments demonstrated that the cationic polymer polylysine induces fusion of anionic liposomes but that the cationic polymer poly(N-ethyl-4-vinylpyridinium bromide) (PEVP) does not, although both polymers bind strongly to the liposomes. The difference was traced to the thickness of the coatings at constant charge coverage. Polylysine is believed to form planar ß-sheets that are sufficiently thin to allow membrane fusion. In contrast, looping and disorganization among adsorbed PEVP molecules physically prevent fusion. A similar effect is likely to be applicable to important polycation-induced fusion of cell membranes.


Asunto(s)
Liposomas/metabolismo , Poliaminas/metabolismo , Polilisina/metabolismo , Polivinilos/metabolismo , Liposomas/ultraestructura , Conformación Molecular , Poliaminas/química , Polielectrolitos , Polilisina/química , Polivinilos/química
19.
Langmuir ; 27(23): 13975-7, 2011 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-22029476

RESUMEN

Surfactant action is caused in part by a dramatic reduction in surface tension. Using surface excess measurements from a radioactive surfactant, it was possible to show that (a) the surface tension declines only slightly when the occupancy of the air/water interface increases from 0 to 60% of the maximum and (b) the steep drop in surface tension in region B (Figure 1 ), frequently observed to be linear, begins at about 80% occupancy. Surfactant continues to enter the interface cooperatively up to and past the critical micelle concentration. Linearity in region B is not indicative of surface saturation despite a seemingly constant surface excess throughout the region. The disparity between interfacial areas determined by surface tension and by other methods is discussed in terms of these results.

20.
Pharmaceuticals (Basel) ; 14(2)2021 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-33573103

RESUMEN

Preparing a suitable formulation for parenteral administration is already a difficult task; this, coupled with poor water-soluble new chemical entity (NCE), complicates this situation even further. There are several methodologies available to enhance water solubility, but this alone does not entail successful formulation. Making a micro/nano emulsion with a suitable surfactant not only increases the drug solubility but also the cell membrane permeability. Thus, not only biopharmaceutic classification system (BCS)-II (low solubility compounds) but also BCS-III (low permeability) and BCS-IV drugs (low solubility and low permeability) can be further exploited. Those drug candidates otherwise will not move further in NCE evaluation or clinical trials. This succinct review article delves into various aspects of biphasic micro/nano emulsion systems for parenteral drug delivery including the structure of the biphasic colloidal systems, characterization parameters, stability issues, regulatory considerations, and applications in life sciences.

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