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Ultraviolet radiation (UVR) has various effects on human cells and tissues, which can lead to a variety of skin diseases and cause inconvenience to people's lives. Among them, solar dermatitis is one of the important risk factors for malignant melanoma, so prevention and treatment of solar dermatitis is very necessary. Additionally, liquiritin (LQ) has anti-inflammatory effects. In this study, we aimed to evaluate the anti-inflammatory and pro-wound healing effects of liquiritin carbomer gel cold paste (LQ-CG-CP) in vitro and in vivo. The results of MTT experiments showed no cytotoxicity of LQ at concentrations of 40 µg/mL and below and cell damage at UVB irradiation doses above 60 mJ/cm2. Moreover, LQ can promote cell migration. ELISA results also showed that LQ inhibited the elevation of the inflammatory factors tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) after UVB irradiation. In the mouse model of solar dermatitis, 2% LQ-CG-CP showed the best therapeutic efficacy for wound healing and relief of itching compared to MEIBAO moist burn moisturizer (MEBO). What is more, the results of skin histopathological examination show that LQ-CG-CP promotes re-epithelialization, shrinks wounds, and promotes collagen production, thus promoting wound healing. Simultaneously, LQ-CG-CP reduced TNF-α, IL-1ß, and IL-6 expression. In addition, LQ-CG-CP was not observed to cause histopathological changes and blood biochemical abnormalities in mice. Overall, LQ-CG-CP has great potential for the treatment of solar dermatitis.
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Resinas Acrílicas , Dermatite , Flavanonas , Glucosídeos , Queimadura Solar , Animais , Camundongos , Humanos , Raios Ultravioleta , Interleucina-6 , Fator de Necrose Tumoral alfa , Cicatrização , Interleucina-1beta , Anti-InflamatóriosRESUMO
Cancer has been an enormous pain point for patients and regulatory bodies across the globe. In Dec. 2023, the US FDA released guidance on benzene-grade carbomer formulations, which triggered pharmaceutical manufacturers to assess risk, test finished products, and reformulate drug products with benzene-grade carbomer. The immediate implementation of the stoppage of finished products with benzene-grade carbomers has threatened pharmaceutical excipients and finished product manufacturers. The gravity of this situation prompted the US Pharmacopeia to extend the deadline for discontinuation from August 1, 2025, to August 1, 2026, allowing manufacturers ample time for reformulation and regulatory compliance.There is an immediate need to understand the guidance and to learn how manufacturers should do the risk assessment and approach reformulation. This review provides an in-depth analysis of the risk assessment and reformulation processes involved in various dosage forms utilizing benzene-grade carbomer, supported by specific case studies.This review offers insights into navigating the USFDA guidelines to ensure formulation safety and compliance, thus enabling pharmaceutical practitioners to uphold the highest standards of patient care and tackle life cycle management challenges.The decision of the USFDA to restrict the usage of high benzene content of carbomer in the formulation is a welcome move. This article has shown a way for researchers to see opportunities in the path and provide best-in-class medicines to patients with a better formulation safety profile.
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Benzeno , United States Food and Drug Administration , Medição de Risco/métodos , Estados Unidos , Benzeno/química , United States Food and Drug Administration/normas , Humanos , Química Farmacêutica/métodos , Excipientes/química , Composição de Medicamentos/métodos , Indústria Farmacêutica/métodos , Indústria Farmacêutica/normas , Resinas Acrílicas/químicaRESUMO
Vaccination is one of the most widely used strategies to protect horses against pathogens. However, available equine vaccines often have limitations, as they do not always provide effective, long-term protection and booster injections are often required. In addition, research efforts are needed to develop effective vaccines against emerging equine pathogens. In this review, we provide an inventory of approved adjuvants for equine vaccines worldwide, and discuss their composition and mode of action when available. A wide range of adjuvants are used in marketed vaccines for horses, the main families being aluminium salts, emulsions, polymers, saponins and ISCOMs. We also present veterinary adjuvants that are already used for vaccination in other species and are currently evaluated in horses to improve equine vaccination and to meet the expected level of protection against pathogens in the equine industry. Finally, we discuss new adjuvants such as liposomes, polylactic acid polymers, inulin, poly-ε-caprolactone nanoparticles and co-polymers that are in development. Our objective is to help professionals in the horse industry understand the composition of marketed equine vaccines in a context of mistrust towards vaccines. Besides, this review provides researchers with a list of adjuvants, either approved or at least evaluated in horses, that could be used either alone or in combination to develop new vaccines.
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Adjuvantes Imunológicos , Nanopartículas , Cavalos , Animais , Adjuvantes Imunológicos/farmacologia , Vacinação/veterinária , Nanopartículas/uso terapêutico , PolímerosRESUMO
Due to its high instability and rapid degradation under adverse conditions, tetracycline hydrochloride (TC) can cause difficulties in the development of an effective but stable formulation for the topical treatment of acne. The aim of the following work was to propose a hydrogel formulation that would ensure the stability of the antibiotic contained in it. Additionally, an important property of the prepared formulations was the activity of the alcoholamines contained in them against the components of the model sebum. This feature may help effectively cleanse the hair follicles in the accumulated sebum layer. A series of formulations with varying proportions of anionic polymer and alcoholamine and containing different polymers have been developed. The stability of tetracycline hydrochloride contained in the hydrogels was evaluated for 28 days by HPLC analysis. Formulations containing a large excess of TRIS alcoholamine led to the rapid degradation of TC from an initial concentration of about 10 µg/mL to about 1 µg/mL after 28 days. At the same time, these formulations showed the highest activity against artificial sebum components. Thanks to appropriately selected proportions of the components, it was possible to develop a formulation that assured the stability of tetracycline for ca. one month, while maintaining formulation activity against the components of model sebum.
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Sebo , Tetraciclina , Tetraciclina/farmacologia , Tetraciclina/metabolismo , Sebo/química , Sebo/metabolismo , Hidrogéis/metabolismo , Antibacterianos/metabolismo , Pele , Polímeros/metabolismoRESUMO
Issues of regeneration of the cornea, which is the most vulnerable structure of the eyeball, suffering from various diseases and injuries, burns, when wearing contact lenses and glaucoma, are highly relevant for ophthalmologists. It is also necessary to minimize damage and stimulate corneal epithelization during and after the use of steroidal and non-steroidal anti-inflammatory drugs, antibacterial drugs and antiseptics, which have a cytotoxic effect and often inhibit regeneration processes, potentially even leading to the development of corneal epithelial defects. This review analyzes the effectiveness of a promising drug 5% dexpanthenol in terms of improving the reparative processes and the function of epithelial cells.
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Lesões da Córnea , Ácido Pantotênico , Humanos , Lentes de Contato , Córnea , Lesões da Córnea/tratamento farmacológico , Ácido Pantotênico/uso terapêuticoRESUMO
BACKGROUND: The stratum corneum poses a formidable barrier for dermal and transdermal delivery of drugs. Besides the stratum corneum barrier, the viable epidermis poses another challenge to pharmaceutical formulators. A drug is probably transdermally permeable if it rapidly crosses the epidermal secondary barrier, while stimulation of lamellar body secretion from granular cells and intracellular release of Ca++ from endoplasmic reticulum (ER) result in retardation. OBJECTIVE: To evaluate the skin permeability of lidocaine HCl loaded in nanoparticles made of carbomer calcified with calcium gluconate, while figuring out the physiological mechanism that regulates the Ca++ related skin barrier function. METHODS: Lidocaine hydrochloride was loaded in a nanoparticulate system based on calcified carbomer, fabricated by using a water-in-oil microemulsion as a precursor. In vitro release and percutaneous permeation testing were carried out to compare between calcified and non-calcified nanoparticles. In addition, comparison was also made between calcified nanoparticles using carbomer gels prepared at two pH values and at two different ratios of Ca++/carbomer. RESULTS: A unique structure of the calcified nanoparticles has been proposed, in which the carbomer nanoparticles are partially coated by gluconate ions through hydrogen bonding and partially through ionic interactions with calcium ions. Although the in vitro release data showed no difference between non-calcified and calcified carbomer nanoparticles, a calcium-related phenomenon of skin retardation has been revealed. CONCLUSIONS: It has been proposed that stimulation of lamellar body secretion from granular cells and Ca++ release from ER, which is elicited by the calcium gluconate-coated nanoparticles, result in dermal retardation of lidocaine.
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Cálcio , Absorção Cutânea , Gluconato de Cálcio/metabolismo , Pele/metabolismo , Administração Cutânea , Portadores de Fármacos/química , Lidocaína/química , Água/química , PermeabilidadeRESUMO
Globally, wound infection is considered to be one of the major healthcare problems, with bacterial infections being the most critical threat, leading to poor and delayed wound healing, and even death. As a superbug, methicillin-resistant Staphylococcus aureus (MRSA) causes a profound hazard to public health safety, prompting us to search for alternative treatment approaches. Herein, the MTT test and Hoechst/propidium iodide (PI) staining demonstrated that PD was slightly less toxic to human fibroblasts including Human keratinocytes (HaCaT) cell line than Silver sulfadiazine (SSD), and Vancomycin (Van). In the MRSA-infected wound model, PD hydrogel (1%, 2.5%) was applied with for 14 days. The wound healing of PD hydrogel groups was superior to the SSD, Van, and control groups. Remarkably, the experimental results showed that PD reduced the number of skin bacteria, reduced inflammation, and upregulated the expression of PCNA (keratinocyte proliferation marker) and CD31 (angiogenesis manufacturer) at the wound site by histology (including hematoxylin-eosin (HE) staining, Masson staining) and immunohistochemistry. Additionally, no toxicity, hemocompatibility or histopathological changes to organs were observed. Altogether, these results suggested the potential of PD hydrogel as a safe, effective, and low toxicity hydrogel for the future clinical treatment of MRSA-infected wounds.
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Staphylococcus aureus Resistente à Meticilina , Infecção dos Ferimentos , Resinas Acrílicas , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Humanos , Hidrogéis/uso terapêutico , Floroglucinol , Cicatrização , Infecção dos Ferimentos/tratamento farmacológicoRESUMO
After extensive studies of 1D and 2D skeletal carbo-mers based on C8 π-conjugating dialkynylbutatriene units (DABs: â¼C≡C-(R)C=C=C=C(R)-C≡Câ¼) bridging sp or sp2 centers in carbo-butene, carbo-xylylene or carbo-benzene derivatives, 3D versions are envisaged through carbo-barrelenes and partially reduced derivatives thereof where two or three DAB blades span a bridge between sp3 carbinol vertices or ether thereof. For R=Ph, stable representatives were synthesized through a pivotal [6]pericyclynedione, and extensively characterized by spectroscopic, electrochemical and crystallographic methods. Density functional theory calculations allow detailed analysis of structural and electronic features of the 7â Å high C26 barrel-shaped molecules, and show that they can behave as cages for ionic species. Beyond aesthetical concerns, the results could open prospects of applications in host-guest supramolecular chemistry and single molecule charge transport.
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Carbono , Carvão VegetalRESUMO
Some commonly used surfactants in cosmetic products raise concerns due to their skin-irritating effects and environmental contamination. Multifunctional, high-performance polymers are good alternatives to overcome these problems. In this study, agarose stearate (AS) with emulsifying, thickening, and gel properties was synthesized. Surfactant-free cosmetic formulations were successfully prepared from AS and carbomer940 (CBM940) mixed systems. The correlation of rheological parameter with skin feeling was determined to study the usability of the mixed systems in cosmetics. Based on rheological analysis, the surfactant-free cosmetic cream (SFC) stabilized by AS-carbomer940 showed shear-thinning behavior and strongly synergistic action. The SFC exhibited a gel-like behavior and had rheological properties similar to commercial cosmetic creams. Scanning electron microscope images proved that the AS-CBM940 network played an important role in SFC's stability. Oil content could reinforce the elastic characteristics of the AS-CBM940 matrix. The SFCs showed a good appearance and sensation during and after rubbing into skin. The knowledge gained from this study may be useful for designing surfactant-free cosmetic cream with rheological properties that can be tailored for particular commercial cosmetic applications. They may also be useful for producing medicine products with highly viscous or gel-like textures, such as some ointments and wound dressings.
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Resinas Acrílicas/síntese química , Cosméticos/síntese química , Excipientes/síntese química , Sefarose/análogos & derivados , Substâncias Viscoelásticas/síntese química , Resinas Acrílicas/química , Cosméticos/química , Excipientes/química , Géis , Humanos , Microscopia Eletrônica de Varredura , Reologia , Sefarose/síntese química , Sefarose/química , Creme para a Pele/síntese química , Creme para a Pele/química , Espectroscopia de Infravermelho com Transformada de Fourier , Tensoativos , Substâncias Viscoelásticas/químicaRESUMO
PURPOSE: Prospective, randomised, open-label, comparative study to evaluate efficacy of trehalose/sodium hyaluronate eye drops for post-operative discomfort and tear film stability in patients undergoing cataract surgery. METHODS: Patients with healthy ocular surface, subclinical, or mild dry eye were enrolled. Tear breakup time (TBUT), Schirmer test, dry eye symptoms, corneal fluorescein staining (CFS), and ocular surface disease (OSDI) evaluation were performed pre-operatively and at two and four weeks after surgery. Patients were assigned to receive trehalose/sodium hyaluronate eye drops b.i.d (Group A), or 0.9% unpreserved sodium chloride eye drops b.i.d for 4 weeks (Group B). RESULTS: One hundred and thirty-five patients were randomised, 66 patients in Group A (73.2 ± 4.5 years) and 69 patients in Group B (74.3 ± 3.8 years), 60.8% females. Fifteen patients (8 Group A) were lost at follow-up. Pre-operatively, no between-group differences were observed, and TBUT increased in Group A between the pre-operative and 2 and 4 week evaluations and was higher in group A than in Group B at 4 weeks. Schirmer test and CFS showed an improvement only in Group A four weeks post-operatively. In Group A an improvement was observed after two and four weeks in foreign body and puncture sensation, whilst a difference in blinking discomfort was observed after four weeks. In Group B we observed an improvement in puncture sensation two and four weeks after surgery. Mean OSDI scores differences between the two groups were significant at four weeks. CONCLUSIONS: Trehalose/sodium hyaluronate eye drops were effective in reducing signs and symptoms of dry eye and improving tear film stability.
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Catarata , Síndromes do Olho Seco , Síndromes do Olho Seco/diagnóstico , Síndromes do Olho Seco/tratamento farmacológico , Síndromes do Olho Seco/etiologia , Feminino , Humanos , Ácido Hialurônico , Masculino , Soluções Oftálmicas , Estudos Prospectivos , Lágrimas , TrealoseRESUMO
carbo-Benzene is an aromatic molecule devised by inserting C2 units within each C-C bond of the benzene molecule. By integrating the corresponding carbo-quinoid core as bridging unit in a π-extended tetrathiafulvalene (exTTF), it is shown that a carbo-benzene ring can be reversibly formed by electrochemical reduction or oxidation. The so-called carbo-exTTF molecule was thus experimentally prepared and studied by UV-visible absorption spectroscopy and cyclic voltammetry, as well as by X-ray crystallography and by scanning tunneling microscopy (STM) on a surface of highly oriented pyrolytic graphite (HOPG). The molecule and its oxidized and reduced forms were subjected to a computational study at the density functional theory (DFT) level, supporting carbo-aromaticity as a driving force for the formation of the dication, radical cation, and radical anion. By allowing co-planarity of the dithiolylidene rings and carbo-quinoidal core, carbo-exTTFs present a promising new class of redox-active systems.
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OBJECTIVE: Probiotic bacteria, such as different lactobacilli strains, have successfully been used to treat gingivitis and periodontitis or caries. By formulating probiotics as orodispersible tablet (ODT), the benefits of this dosage form could be utilized. Without any further measures, the probiotic bacteria will be eliminated too fast from the intended site of action, the oral mucosa. The use of mucoadhesive granules, composed of mucoadhesive polymer and probiotics, is a promising strategy to prolong the contact time between lactobacilli and oral mucosa without delaying disintegration. METHODS: Three common mucoadhesive polymers, anionic Carbopol 971P NF, nonionic Metolose 65SH50 and cationic chitosan were included into tablets either by direct compression (DC) or after granulation with the probiotics. Disintegration, mucoadhesion of the tablets, and storage stability of the probiotics were characterized. RESULTS: By incorporating a sufficient amount of polymer superior probiotic mucoadhesion could be achieved. All formulations based on granulated probiotics and mucoadhesive polymer fulfilled the Food and Drug Administration (FDA) acceptance level for disintegration of orodispersible tablets. These formulations exhibited excellent storage stability under refrigerated conditions over 30 months. Interestingly, ODTs including Carbopol 971P NF still proved superior mucoadhesion after long-term storage, whereas the mucoadhesive effect of Metolose 65SH50 and chitosan declined markedly. CONCLUSIONS: The results of this study suggest that Carbopol 971P NF was the most appropriate polymer for a probiotic mucoadhesive ODT.
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Polímeros/química , Probióticos , Adesividade , Administração Bucal , Mucosa Bucal/efeitos dos fármacos , ComprimidosRESUMO
The physicochemical properties, especially pH value of dental medicines, have significant influence on the health of oral cavity tissues. The pH of formulations should correspond to the value of saliva pH (5.5-8.0). For carbomer-based gels, the required pH value is obtained by neutralizing them with alkaline components, which leads to their structuring (thickening). This affects the physical properties of the gel, its residence time at the application site and the rate of release of active pharmaceutical ingredient. Therefore, the main purpose of this study is to evaluate the rheological, textural, and biopharmaceutical properties of Carbomer Polacril® 40P-based dental gel depending on the pH value. Evaluation of the rheological properties of gel preparations were performed by measuring the structural viscosity of the samples as a function of pH and temperature. The textural properties of the gel were evaluated by performing tests regarding back extrusion and spreadability. Carbomer Polacril® 40P-based gels haven't shown noticeable thixotropic behavior, and were characterized by plastic flow in the whole studied pH range. The structural viscosity at the selected average pH value hasn't differed at storage (25 °C) and application (37 °C) temperature. Texture studies of dental gels have shown a strong correlation with rheoparameters. Their rheological behavior and textural properties haven't changed significantly between the pH range of 5.5-6.6. The relatively narrow range of working pH values does not affect the change in the viscosity of the preparation significantly and, consequently, does not affect the release of APIs from the developed Carbomer Polacril® 40P-based dental gel.
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Resinas Acrílicas/química , Dentifrícios/química , Extratos Vegetais/química , Géis , Concentração de Íons de Hidrogênio , Reologia , ViscosidadeRESUMO
OBJECTIVE: To evaluate the survival of atraumatic restorative treatment (ART) restorations using high viscosity glass ionomer cement (GIC), compomer (COM), and glass carbomer (CAR) for occlusal and occlusoproximal cavitated dentin caries lesions in primary molars. METHODS: A total of 568 4-7-year-old children (287 occlusoproximal and 281 occlusal cavities) were selected in Barueri, Brazil. The patients were randomly allocated in three groups: GIC, COM, and CAR. All treatments were performed on school setting following ART premises. Evaluations were performed after 2, 6, 12, 18, 24, and 36 months. Restoration survival was evaluated using Kaplan-Meier survival analysis and log-rank test, while Cox regression analysis was used for testing association with clinical factors (α = 5%). RESULTS: The overall survival rate after 3 years of occlusal ART restorations was 73% (GIC = 83%; COM = 78%; CAR = 62%) and 49% for occlusoproximal ART restorations (GIC = 56%; COM = 56%; CAR = 36%). CAR restorations were less successful than GIC and COM for both occlusal and occlusoproximal restorations (p < 0.05). No difference was found between GIC and COM (p > 0.05). CONCLUSIONS: GIC and compomer are clinically more successful than CAR for occlusal and occlusoproximal restorations in primary molars. CLINICAL SIGNIFICANCE: Both compomer and high viscosity glass ionomer cement are suitable materials for ART in primary molars. However, glass carbomer cement should not be used for ART (#NCT02217098).
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Apatitas , Compômeros , Tratamento Dentário Restaurador sem Trauma , Cárie Dentária/terapia , Cimentos de Ionômeros de Vidro , Resinas Acrílicas , Brasil , Criança , Falha de Restauração Dentária , Restauração Dentária Permanente , HumanosRESUMO
OBJECTIVE: The aim of this study was to develop, characterize and evaluate stability of a gel containing coenzyme Q10 (Q10)-loaded liposomes, and enhance the stability of Q10 in the nanocarrier-containing gel compared to the conventional gel. METHODS: Q10-loaded liposome dispersions prepared from unsaturated or saturated lecithin, were characterized for particle size, polydispersity index (PDI), zeta-potential, pH value, oxidation index, Q10-content and morphology, and incorporated into carbomer gel. Liposome gels and liposome-free gel were analyzed for flow properties, pH values, Q10-content, and liposomes size and PDI (liposome gels), 48 h after preparation and in predetermined time intervals during 6 months storage at different temperatures in order to predict their long term stability. RESULTS: Liposomes were of small particle size, homogeneous, negatively charged, and their incorporation into gel did not significantly change (p > .05) their particle size and PDI. All gels revealed non-Newtonian, shear-thinning plastic flow behavior during storage with no marked changes in rheological parameters. Storage of gels did not significantly influence the pH value (p > .05), while it significantly decreased Q10-content (p < .05). Q10 was significantly more (p < .05) stable in liposome gel containing unsaturated lecithin liposomes (G1) than in gel containing saturated lecithin liposomes (G2) and liposome-free gel (G3). CONCLUSIONS: Q10-loaded liposome gel G1 was the optimal formulation, since during storage at different temperatures, it did not show significant increase in liposome size and PDI, it provided significantly higher stability for Q10 than other gels and its pH value was suitable for skin application. Due to limited Q10-stability it should be stored at 4 °C.
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Química Farmacêutica/métodos , Géis/síntese química , Reologia/métodos , Ubiquinona/análogos & derivados , Estabilidade de Medicamentos , Géis/análise , Interações Hidrofóbicas e Hidrofílicas , Lipossomos , Ubiquinona/análise , Ubiquinona/síntese química , Vitaminas/análise , Vitaminas/síntese químicaRESUMO
OBJECTIVES: The aim of this study was to evaluate potential development of montelukast sodium (MTS) as a nasal spray. MATERIALS AND METHODS: The formulations were prepared using hydroxypropyl cellulose (HPC) and carbomer 940 (C940). The prepared formulations were evaluated for clarity, pH, hydrodynamic size, zeta potential, viscosity, contact angle, surface tension, droplet size distribution, muco-adhesiveness, drug release, and stability. The suitable formulations were also assessed for their effects on nasal epithelial cells. RESULTS AND DISCUSSION: At room temperature (25 °C), the formulation containing 0.01% w/v C940 exhibited suitable viscosity and rheological properties. Spray droplets were in ranges of 10-40 µm, which are suitable for nasal administration. The works of adhesion of the formulations containing HPC or C940 were in the range of 0.8-4.0 and 0.2-27 µJ, respectively. In addition, the formulation containing 0.01% w/v C940 and the 0.5-15 µg/50 µL concentrations of MTS showed no signs of cytotoxicity and did not open the tight junction of nasal epithelial cells. CONCLUSION: The formulated MTS nasal spray is ideal for nasal administration for the treatment of allergic rhinitis. The formulation containing 0.01% w/v C940 had no toxicity nor alteration on the tight junction of nasal epithelial cells.
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Acetatos/química , Antiasmáticos/química , Desenvolvimento de Medicamentos/métodos , Células Epiteliais/efeitos dos fármacos , Sprays Nasais , Quinolinas/química , Acetatos/farmacologia , Antiasmáticos/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Ciclopropanos , Relação Dose-Resposta a Droga , Composição de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Células Epiteliais/metabolismo , Humanos , Quinolinas/farmacologia , SulfetosRESUMO
BACKGROUND: The objective of our study was to compare the upper and lower surface microhardness and surface changes of Glass Carbomer Cement (GCP) and EQUIA Forte (EF) in different thickness after thermo-light curing durations and aging. METHODS: A total of 504 samples (5 mm-diameter) were prepared by using GCP-252 (GCP Dental, and Vianen, Netherlands) and EF-252 (EQUIA Forte, GC, Tokyo, Japan). Three different thickness samples (2, 4, and 6 mm) were prepared with 84 samples in each subgroup. The samples were prepared by three curing procedures (Non-exposed, 60s, 90s). Their varnishes were applied to the upper surfaces of half of each subgroup (n = 7). The upper microhardness measurements were evaluated before and after aging. To compare the effect of different thicknesses, the bottom surfaces of the samples were evaluated before aging in terms of microhardness measurements. Also, the upper surfaces were analyzed in the SEM before and after aging. RESULTS: The upper surface values of all the samples were higher than the bottom values (p < 0.05). There were no significant differences between the varnished and non-varnished samples in both materials (p > 0.05). Although this increase was not significant in some groups, temperature variations increased the surface microhardness values of both materials except for the non-exposed-varnished EF samples. The highest microhardnesses values were recorded in the non-exposed-varnished EF (125.6 ± 6.79) and unvarnished GCP (88.1 ± 7.59) samples which were thermo-light cured for 90 s before aging. The bottom hardness values were affected by thickness variations in both GCP and EF materials (p < 0.05). The sample deformations and microcracks after aging were greater than before in all the materials. Thermo-light curing in 90 s to the samples reduced the cracks in both the materials before and after aging. CONCLUSIONS: Thermal aging adversely affected the microhardness of the materials, which is important for clinical success. The thermo-light curing process improved the microhardness of the GCP group without varnish application. Varnish application increased the microhardness of the EF group without applying thermo-light curing. The microhardness of the bottom surfaces decreased with increasing thickness. The thermo-light curing did not increase the bottom surface microhardness of all the samples.
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Apatitas/química , Lâmpadas de Polimerização Dentária , Cimentos de Ionômeros de Vidro/química , Cimentos de Ionômeros de Vidro/efeitos da radiação , Resinas Acrílicas , Resinas Compostas/efeitos da radiação , Dureza , Humanos , Japão , Teste de Materiais , Países Baixos , Propriedades de Superfície , Temperatura , Fatores de TempoRESUMO
In the development of drug delivery systems, an oral drug delivery system is the preferred route of drug administration. Many components play an important role in developing a drug delivery system. Amongst those components, polymers have evolved with these systems. Macromolecule compounds consisting of many monomer units which are joined to each other by different bonds are known as polymers. For drugs that are absorbed primarily in the upper gastrointestinal tract, floating drug delivery systems offer an additional advantage. The purpose behind this review was to focus on different types of floating drug delivery systems and different types of polymers used in floating drug delivery systems, focusing on acrylic acid derivatives and their applications. In this review, the main emphasis is on acrylic acid derivative polymers, their formulation and grades, and various patents on these types of polymers. Based on the literature survey, mainly 2 types of polymers are used in this drug delivery system; i.e., natural and synthetic. Examples of natural polymers are xanthan gum, guar gum or chitosan, and synthetic polymers include acrylic acid derivatives and hydroxylpropyl methylcellulose (HPMC). Eudragit and Carbopol are the most widely used acrylic acid derivatives.
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Acrilatos , Química Farmacêutica , Sistemas de Liberação de Medicamentos , Polímeros , Preparações de Ação Retardada , Derivados da Hipromelose , ComprimidosRESUMO
BACKGROUND: The overall success of dental restorations depends on the materials' ability to bond to dental structures and to eliminate the microleakage. Therefore, the aim of this study was to evaluate the shear bond strength (SBS) and microleakage of novel glass-ionomer restorative materials. MATERIALS AND METHODS: In this study 62 intact molars were used, of which 30 molars were sectioned buccolingually, embedded in acrylic resin, and polished to obtain flat dentin surfaces. Then, glass-ionomer cylinders were built on the specimens (n = 15) with a high-viscosity glass-ionomer cement (GIC) (EQUIA Fil), a glass-carbomer (Glassfill), a zirconia-reinforced GIC (Zirconomer), or a conventional GIC (RivaSelfCure), and SBS testing was performed. For microleakage test, Class V cavities were prepared on buccal and lingual surfaces of the remaining 32 teeth and divided into four groups (n = 16). Each group was restored with one of four GICs and subjected to microleakage testing. The data were statistically analyzed (P = 0.05). RESULTS: The highest SBS values were observed in Glassfill group (P < 0.05). There were no significant differences on the SBS values of other three materials (P > 0.05). Regarding microleakage evaluations, no significant differences were observed at enamel margins (P > 0.05), whereas at dentin margins, EQUIA Fil and Zirconomer showed less microleakage than Glassfill (P < 0.05). CONCLUSIONS: Although the glass-carbomer restorative materials revealed higher SBS, other tested materials might be more reliable in clinical use, as they offer better leakage resistance.
Assuntos
Colagem Dentária , Infiltração Dentária , Restauração Dentária Permanente , Cimentos de Ionômeros de Vidro , Teste de Materiais/métodos , Resistência ao Cisalhamento , Apatitas , Materiais Dentários , Humanos , Cimentos de Resina , ZircônioRESUMO
CONTEXT: Atopic dermatitis (AD) is a chronic skin disease characterized by inflammation of the skin and has exhibited remarkable repercussions on human life across the globe. Fluocinolone acetonide (FA), a topical corticosteroid is employed in the treatment of atopic dermatitis, but suffers from limited penetration into deeper epidermis of atopic skin. OBJECTIVE: The present investigation was focused to explore the utility of ß-cylcoethosomes in improvising the penetration deep into the skin. MATERIALS AND METHODS: ß-Cylcoethosomes developed using ß-cycloamylose by injection method were evaluated for vesicle size, entrapment efficiency and in vitro release. Central Composite design employed for the preparation depicted FA8 as an optimized formulation which was then formulated as dermatological gel using carbomer 934P as a gel base. The gels were characterized for pH, viscosity, drug content and in vitro permeability. RESULTS AND DISCUSSION: Optimized formulation (FA8) showed maximum desirability (0.795) with vesicle size of 228.33 ± 1.23 nm), EE (82.49 ± 1.21%) and CDR (90.90 ± 0.29%). FA8-loaded gels showed maximum in vitro permeability as found in BG and BGP (83.22 ± 0.72% and 84.02 ± 0.87). BG was selected as an optimized gel and compared with optimized reference ethosomal gel and control gel. CLSM studies depicted deeper uniform penetration of fluorescent dye deep into the epidermis via BG. Improved penetration was observed due to the synergistic effect exerted by ethanol and ß-cycloamylose. CONCLUSION: ß-cylcoethosomes proved to be a promising carrier for improvised penetration of fluocinolone acetonide via topical gel.