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1.
Confl Health ; 15(1): 78, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34727960

RESUMO

BACKGROUND: The Syrian conflict has created the worst humanitarian refugee crisis of our time, with the largest number of people displaced. Many have sought refuge in Egypt, where they are provided with the same access to healthcare services as Egyptian citizens. Nevertheless, in addition to the existing shortcomings of the Egyptian health system, many obstacles specifically limit refugees' access to healthcare. This study looks to assess equity across levels of care after observing services utilization among the Syrian refugees, and look at the humanitarian dilemma when facing resource allocation and the protection of the most vulnerable. METHODS: A cross-sectional survey was used and collected information related to access and utilization of outpatient and inpatient health services by Syrian refugees living in Egypt. We used concentration index (CI), horizontal inequity (HI) and benefit incidence analysis (BIA) to measure the inequity in the use of healthcare services and distribution of funding. We decomposed inequalities in utilization, using a linear approximation of a probit model to measure the contribution of need, non-need and consumption influential factors. RESULTS: We found pro-rich inequality and horizontal inequity in the probability of refugees' outpatient and inpatient health services utilization. Overall, poorer population groups have greater healthcare needs, while richer groups use the services more extensively. Decomposition analysis showed that the main contributor to inequality is socioeconomic status, with other elements such as large families, the presence of chronic disease and duration of asylum in Egypt further contributing to inequality. Benefit incidence analysis showed that the net benefit distribution of subsidies of UNHCR for outpatient and inpatient care is also pro-rich, after accounting for out-of-pocket expenditures. CONCLUSION: Our results show that without equitable subsidies, poor refugees cannot afford healthcare services. To tackle health inequities, UNHCR and organisations will need to adapt programmes to address the social determinants of health, through interventions within many sectors. Our findings contribute to assessments of different levels of accessibility to healthcare services and uncover related sources of inequities that require further attention and advocacy by policymakers.

2.
J Cosmet Sci ; 69(3): 203-212, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30052194

RESUMO

A mechanistic understanding of the role of polymers in waterproofing anhydrous sunscreen formulations has been hypothesized in the past, but has never been clearly established. In this article, we demonstrate the utility of field emission scanning electron microscopy (SEM) to generate images of sunscreen films in the presence and absence of several polymers. VA/butyl maleate/isobornyl acrylate copolymer was studied alone and in combination with hydroxypropyl cellulose and acrylates/dimethicone copolymer. Anhydrous sunscreen formulations were sprayed onto stratum corneum substrates and left to dry. SEM micrographs of treated stratum corneum sections were then collected at various magnifications. Vapor transmission data were collected using an evaporimeter to understand the permeability of these films in the presence and absence of film formers. Examination of the SEM images reveals that after spraying the product onto a layer of corneocytes, the sunscreen filters formed a hydrophobic barrier over the skin, whereas added polymers formed films over the sunscreen layer. The shape of the film formed by various polymers and its porosity were influenced by chemistry and concentration. When more than one polymer was incorporated in the sunscreen formulation, the interactions between the polymers influenced the formation of the film. Cumulative evaporimeter data indicated that the sunscreen phase had the highest reduction in cumulative evaporation rate (39.3%/h) followed by the addition of a film former to the spray, which reached an additional reduction of 17.9%/h in the best case. This method was also used to examine the film properties of a commercial sun protection factor 30 sunscreen product containing VA/butyl maleate/isobornyl acrylate copolymer. SEM micrographs of the commercial product applied to skin showed the same fingerprint as prototype formulations containing VA/butyl maleate/isobornyl acrylate copolymer. Overall, this method can be used by sun care scientists in the development and optimization of anhydrous sunscreen sprays.


Assuntos
Polímeros/química , Protetores Solares/química , Composição de Medicamentos , Gases/análise , Voluntários Saudáveis , Humanos , Microscopia Eletrônica de Varredura , Pele/química , Pele/efeitos dos fármacos , Fator de Proteção Solar
3.
J Cosmet Sci ; 67(3): 121-59, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-29394015

RESUMO

Identifying meaningful and measurable rheological parameters that shadow the dynamic shear stresses sustained in the initial application and subsequent spreading of structured cosmetic formulations onto the skin is quite challenging. When applied to non-Newtonian soft solids, traditional oscillatory rheological testing tends to best correlate with the "at-rest" state, or, more fundamentally, with the initial and thermodynamically reversible perturbations in the physiochemical networking that binds components of the amalgamated microstructure. In addition, after yielding, as an applied film is further thinned while spreading on the skin surface, shear rates during flow processes may rapidly and dynamically increase to 104 s⁻¹ , which is a magnitude that is not practically simulated with a standard rotational rheometer. Realistically speaking, it is rare that a single rheological measurement or resultant parameter predicts the sensorial appeal of a complex fluid during the entire scope of a spreading process. Large amplitude oscillatory shear (LAOS) methodology is an augmentation of standard oscillatory rheology, or small amplitude oscillatory shear (SAOS), and delivers a means to dynamically probe the deforming microstructure of a soft solid as it rheologically transitioned from a viscoplastic material to a structured fluid. LAOS rheology was performed on four different prototypes having different skincare textures to produce Bowditch­Lissajous plots (henceforth truncated to Lissajous in the remainder of the document) for subsequent association with previously measured sensorial properties. Insights into the shapes of the curves and their relation to paralleled sensorial analyses are primarily based on the performance of the composite prototypes rather than speculating on the individual contribution of each constituent to the dynamics of the adapting microstructure. Therefore, transitions in the Lissajous trajectories may be used to visually describe changes in the bulk rheology as the physical components of the local viscoelastic environment are controllably sheared. In this work, Lissajous profiles are amassed with smooth and rough surfaces data utilizing standard rheological techniques, including oscillatory SAOS, stress ramps, Brookfield viscometry, and the manifestation of interfacial or complex flow properties, such as wall-slip and shear-banding phenomena. Practical influences on the human stratum corneum, including thermal softening and electrostatic shielding, are also considered. Additionally, outcomes from texture profile analysis are reported and contrasted with the accompanying results. Ultimately, the objective is to make meaningful connections between trends in Lissajous trajectories and paralleled sensorial analyses conducted by a trained expert panel. For the reader, a basic level of rheological knowledge is assumed.


Assuntos
Cosméticos/química , Composição de Medicamentos , Humanos , Reologia , Higiene da Pele , Fenômenos Fisiológicos da Pele
4.
J Cosmet Sci ; 63(3): 213-21, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23193694

RESUMO

The aim of this study was to investigate the mechanism by which a VA/butyl maleate/isobornyl acrylate copolymer increases the SPF and water resistance of sunscreen formulations. Anhydrous sunscreen formulations with and without polymer were applied on polymethyl methacrylate (PMMA) plates and absorbance spectra were generated. Before immersion, the areas under the curve for the control and test samples were 98.49 and 117.09, respectively, and were 94.63 and 118.22, after immersion. Static and after-immersion, in vivo SPF values confirmed a boost in SPF and an increase in water resistance for the formulation containing the polymer (VA/butyl maleate/isobornyl acrylate copolymer). Digital imaging of sunscreen films combined with image analysis and contact angle measurements suggest that the polymer conformation changes upon exposure to water. The polymer forms a protective barrier over the sunscreen film upon exposure to water, which explains the enhancement in water resistance. The polymeric film formed has a different refractive index than the sunscreen film. The change in refractive indices causes diffraction of incident light, thus increasing its pathlength, leading to an increase in SPF.


Assuntos
Polímeros/química , Protetores Solares/química , Área Sob a Curva , Humanos , Interações Hidrofóbicas e Hidrofílicas , Absorção Cutânea , Espectrofotometria Ultravioleta , Fator de Proteção Solar/métodos
5.
J Cosmet Sci ; 62(3): 317-25, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21839034

RESUMO

In this study, digital photography in combination with image analysis was used to measure the luster of several lipstick formulations containing varying amounts and types of polymers. A weighed amount of lipstick was applied to a mannequin's lips and the mannequin was illuminated by a uniform beam of a white light source. Digital images of the mannequin were captured with a high-resolution camera and the images were analyzed using image analysis software. Luster analysis was performed using Stamm (L(Stamm)) and Reich-Robbins (L(R-R)) luster parameters. Statistical analysis was performed on each luster parameter (L(Stamm) and L(R-R)), peak height, and peak width. Peak heights for lipstick formulation containing 11% and 5% VP/eicosene copolymer were statistically different from those of the control. The L(Stamm) and L(R-R) parameters for the treatment containing 11% VP/eicosene copolymer were statistically different from these of the control. Based on the results obtained in this study, we are able to determine whether a polymer is a good pigment dispersant and contributes to visually detected shine of a lipstick upon application. The methodology presented in this paper could serve as a tool for investigators to screen their ingredients for shine in lipstick formulations.


Assuntos
Cosméticos , Lábio , Humanos
6.
J Cosmet Sci ; 55(1): 65-80, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15037921

RESUMO

Salicylic acid (SA) is a beta hydroxy acid and has multifunctional uses in the treatment of various diseases in skin such as acne, psoriasis, and photoaging. One problem often cited as associated with salicylic acid is that it can be quite irritating at pH 3-4, where it exhibits the highest activity in the treatment of skin diseases. We have identified strategies to control the irritation potential of salicylic acid formulations and have focused on hydroalcoholic solutions used in acne wipes. One strategy is to control the penetration of SA into the skin. Penetration of the drug into various layers of skin, i.e., epidermis, dermis, and receptor fluid, was measured using a modified Franz in vitro diffusion method after various exposure times up to 24 hours. A polyurethane polymer (polyolprepolymer-15) was found to be an effective agent in controlling delivery of SA. In a dose-dependent fashion it targeted delivery of more SA to the epidermis as compared to penetration through the skin into the receptor fluid. It also reduced the rapid rate of permeation of a large dose of SA through the skin in the first few hours of exposure. A second strategy that proved successful was incorporation of known mild nonionic surfactants like isoceteth-20. These surfactants cleanse the skin, yet due to their inherent mildness (because of their reduced critical micelle concentration and monomer concentration), keep the barrier intact. Also, they reduce the rate of salicylic acid penetration, presumably through micellar entrapment (either in solution or on the skin surface after the alcohol evaporates). Cumulative irritation studies showed that targeting delivery of SA to the epidermis and reducing the rapid early rate of penetration of large amounts of drug through the skin resulted in a reduced irritation potential. In vivo irritation studies also showed that the surfactant system is the most important factor controlling irritancy. SA delivery is secondary, as formulations with less SA content reduced the rate of delivery to the receptor and yet were some of the most irritating formulations tested, presumably due to the action of the specific anionic surfactant on the barrier. Alcohol content also did not appreciably affect irritation and SA delivery; formulations with considerably lower alcohol content but containing anionic versus nonionic surfactant systems exhibited considerably higher irritancy. Thus the surfactant type was again the predominant factor in those studies, although arguably alcohol plays some role (solubilization of SA). Results showed that both polymers and mild surfactants work in concert to provide the optimal formulation benefits of targeted delivery and reduced irritation. Synergistic relationships among hydroalcoholic formulation components will be discussed along with the mechanisms likely involved in controlling delivery of SA to skin.


Assuntos
Salicilatos/administração & dosagem , Salicilatos/efeitos adversos , Absorção Cutânea/fisiologia , Pele/efeitos dos fármacos , Acne Vulgar/tratamento farmacológico , Administração Cutânea , Química Farmacêutica , Humanos , Técnicas In Vitro , Poliuretanos/administração & dosagem , Poliuretanos/química , Poliuretanos/farmacocinética , Salicilatos/química , Salicilatos/farmacocinética , Pele/metabolismo , Testes de Irritação da Pele , Tensoativos/administração & dosagem , Tensoativos/química , Tensoativos/farmacocinética
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