Hydrophobic and Hydrophilic Film-Forming Gels for the Controlled Delivery of Drugs with Different Levels of Hydrophobicity

2020 ◽  
Vol 21 ◽  
Author(s):  
Khanh T. Nguyen ◽  
Phuong H.L. Tran ◽  
Hai V. Ngo ◽  
Thao T.D. Tran
Keyword(s):  
Sustained Release ◽  
Hydroxypropyl Methylcellulose ◽  
Controlled Delivery ◽  
Drying Time ◽  
Terbinafine Hydrochloride ◽  
Sustained Drug Delivery ◽  
Film Forming ◽  
Wide Range ◽  
Highly Hydrophobic ◽  
Different Levels

Background: This study aimed to evaluate the effects of hydrophobic and hydrophilic film-forming gels (FFGs) on the controlled delivery of drugs with different levels of hydrophobicity. Methods: This evaluation was carried out by employing zein and polyvinylpyrrolidone as hydrophobic and hydrophilic film-forming agents, respectively, in combination with hydroxypropyl methylcellulose functionalized as a hydrogel basement at a ratio that had been optimized to achieve the fastest drying time. Free curcumin or terbinafine hydrochloride was subsequently dispersed into blank FFGs to produce the final FFG formulations. Results: Although the extreme hydrophobicity of curcumin strongly limited its topical permeability compared to that of terbinafine hydrochloride, zein FFGs clearly resulted in a favourable sustained release system for highly hydrophobic drugs, such as curcumin. Moreover, polyvinylpyrrolidone would be highly effective for the sustained release of a less hydrophobic drug, such as terbinafine hydrochloride. Analyses of the wettability, surface morphology, chemical interactions and crystallinity of FFGs also helped to elucidate the mechanisms of their drug release profiles. Conclusion: This fundamental finding is beneficial for further design studies on FFGs as sustained drug delivery systems for topical drugs with a wide range of hydrophobicities.

scholarly journals Film-Forming Systems for the Delivery of DNDI-0690 to Treat Cutaneous Leishmaniasis

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 516
Author(s):  
Katrien Van Bocxlaer ◽  
Kerri-Nicola McArthur ◽  
Andy Harris ◽  
Mo Alavijeh ◽  
Stéphanie Braillard ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Cutaneous Leishmaniasis ◽  
Mouse Skin ◽  
Parasite Load ◽  
Leishmania Species ◽  
Lesion Size ◽  
Drying Time ◽  
Sustained Drug Delivery ◽  
Film Forming ◽  
The Impact

In cutaneous leishmaniasis (CL), parasites reside in the dermis, creating an opportunity for local drug administration potentially reducing adverse effects and improving treatment adherence compared to current therapies. Polymeric film-forming systems (FFSs) are directly applied to the skin and form a thin film as the solvent evaporates. In contrast to conventional topical dosage forms, FFSs strongly adhere to the skin, favouring sustained drug delivery to the affected site, reducing the need for frequent applications, and enhancing patient compliance. This study reports the first investigation of the use of film-forming systems for the delivery of DNDI-0690, a nitroimidazole compound with potent activity against CL-causing Leishmania species. A total of seven polymers with or without plasticiser were evaluated for drying time, stickiness, film-flexibility, and cosmetic attributes; three FFSs yielded a positive evaluation for all test parameters. The impact of each of these FFSs on the permeation of the model skin permeant hydrocortisone (hydrocortisone, 1% (w/v) across the Strat-M membrane was evaluated, and the formulations resulting in the highest and lowest permeation flux (Klucel LF with triethyl citrate and Eudragit RS with dibutyl sebacate, respectively) were selected as the FFS vehicle for DNDI-0690. The release and skin distribution of the drug upon application to Leishmania-infected and uninfected BALB/c mouse skin were examined using Franz diffusion cells followed by an evaluation of the efficacy of both DNDI-0690 FFSs (1% (w/v)) in an experimental CL model. Whereas the Eudragit film resulted in a higher permeation of DNDI-0690, the Klucel film was able to deposit four times more drug into the skin, where the parasite resides. Of the FFSs formulations, only the Eudragit system resulted in a reduced parasite load, but not reduced lesion size, when compared to the vehicle only control. Whereas drug delivery into the skin was successfully modulated using different FFS systems, the FFS systems selected were not effective for the topical application of DNDI-0690. The convenience and aesthetic of FFS systems alongside their ability to modulate drug delivery to and into the skin merit further investigation using other promising antileishmanial drugs.

Film-Forming Nanogels: Effects of Nanocarriers and Film-Forming Gel on the Sustained Release of Curcumin

2020 ◽  
Vol 20 ◽  
Author(s):  
Khanh T. Nguyen ◽  
Phuong H.L. Tran ◽  
Hai V. Ngo ◽  
Thao T.D. Tran
Keyword(s):  
Sustained Release ◽  
Hydroxypropyl Methylcellulose ◽  
Dosage Forms ◽  
Free Drug ◽  
Water Soluble ◽  
Hydrophobic Drug ◽  
Water Soluble Drug ◽  
Film Forming ◽  
Poorly Water Soluble ◽  
Poorly Water Soluble Drug

Background: Although film-forming hydrogels possess the advantages of both film and hydrogel dosage forms, certain limitations still remain. Objective: This study aims to investigate the use of film-forming hydrogels and the effects of nanocarriers on the sustained release of a poorly water-soluble drug, curcumin. Methods: The film-forming hydrogels contained either zein or polyvinylpyrrolidone as a film former, in addition to hydroxypropyl methylcellulose, oleic acid, ethanol and water. Curcumin was encapsulated in poly(lactic-co-glycolic acid) and gelatine nanoparticles using a sonoprecipitation method. Free drug and drug-loaded nanoparticles were later dispersed into blank hydrogels to produce the film-forming nanogels. Results: The results suggested that the encapsulation of curcumin in nanoparticles could reduce the drug particle size to less than 200nm for easier diffusion and could shield curcumin from chemical interactions that limit its topical permeability. curcumin was more compatible with gelatine nanoparticles than with poly(lactic-coglycolic acid) nanoparticles, and gelatine nanoparticles, in turn, were more compatible with zein than with polyvinylpyrrolidone film-forming nanogels. Therefore, gelatine nanoparticles in zein filmforming nanogels greatly elevated the permeability of curcumin by over five times that afforded by gelatine nanoparticles in polyvinylpyrrolidone film-forming nanogels. Conclusion: This research suggested that film-forming nanogel is a promising drug delivery system for both improved permeability and sustained topical diffusion of the extremely hydrophobic drug curcumin depending on the compatibility between the nanocarrier and the film-forming hydrogel.

Influencia de las condiciones de secado solar en la coloración de plantas medicinales

2019 ◽  
pp. 28-34
Author(s):  
Margarita Castillo-Téllez ◽  
Beatriz Castillo-Téllez ◽  
Juan Carlos Ovando-Sierra ◽  
Luz María Hernández-Cruz
Keyword(s):  
Medicinal Plants ◽  
Forced Convection ◽  
Rural Areas ◽  
Color Change ◽  
Drying Process ◽  
Scientific Medicine ◽  
Drying Time ◽  
Bacterial Proliferation ◽  
Wide Range ◽  
Very High

For millennia, humans have used hundreds of medicinal plants to treat diseases. Currently, many species with important characteristics are known to alleviate a wide range of health problems, mainly in rural areas, where the use of these resources is very high, even replacing scientific medicine almost completely. This paper presents the dehydration of medicinal plants that are grown in the State of Campeche through direct and indirect solar technologies in order to evaluate the influence of air flow and temperature on the color of the final product through the L* a* scale. b*, analyzing the activity of water and humidity during the drying process. The experimental results showed that the direct solar dryer with forced convection presents a little significant color change in a drying time of 400 min on average, guaranteeing the null bacterial proliferation and reaching a final humidity between 9 % and 11 %.

Development and Evaluation of Sustained Release Lipid Nanocarriers for Curcumin

2020 ◽  
Vol 5 (3) ◽  
pp. 224-235
Author(s):  
Harshal A. Pawar ◽  
Bhagyashree D. Bhangale
Keyword(s):  
Drug Delivery ◽  
Sustained Release ◽  
Drug Delivery Systems ◽  
Biological Activities ◽  
Curcuma Longa ◽  
Research Work ◽  
Elimination Rate ◽  
Delivery Systems ◽  
Physicochemical Stability ◽  
Wide Range

Background: Lipid based excipients have increased acceptance nowadays in the development of novel drug delivery systems in order to improve their pharmacokinetic profiles. Drugs encapsulated in lipids have enhanced stability due to the protection they experience in the lipid core of these nano-formulations. Phytosomes are newly discovered drug delivery systems and novel botanical formulation to produce lipophilic molecular complex which imparts stability, increases absorption and bioavailability of phytoconstituent. Curcumin, obtained from turmeric (Curcuma longa), has a wide range of biological activities. The poor solubility and wettability of curcumin are responsible for poor dissolution and this, in turn, results in poor bioavailability. To overcome these limitations, the curcumin-loaded nano phytosomes were developed to improve its physicochemical stability and bioavailability. Objective: The objective of the present research work was to develop nano-phytosomes of curcumin to improve its physicochemical stability and bioavailability. Methods: Curcumin-loaded nano phytosomes were prepared by using phospholipid Phospholipon 90 H using a modified solvent evaporation method. The developed curcumin nano phytosomes were evaluated by particle size analyzer and differential scanning calorimetry (DSC). Results: Results indicated that phytosomes prepared using curcumin and lipid in the ratio of 1:2 show good entrapment efficiency. The obtained curcumin phytosomes were spherical in shape with a size less than 100 nm. The prepared nano phytosomal formulation of curcumin showed promising potential as an antioxidant. Conclusion: The phytosomal complex showed sustained release of curcumin from vesicles. The sustained release of curcumin from phytosome may improve its absorption and lowers the elimination rate with an increase in bioavailability.

Preparation and Property Study of Core-Shell Ambient-Temperature Crosslinkable Polyacrylate Binder

2013 ◽  
Vol 469 ◽  
pp. 3-6 ◽  
Author(s):  
Mu Li ◽  
Xiao Song Lin ◽  
Xiao Yu Li ◽  
Hai Qiao Wang
Keyword(s):  
Ambient Temperature ◽  
Butyl Acrylate ◽  
Core Shell ◽  
Drying Time ◽  
Acrylic Polymer ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Film Forming ◽  
Water Based

As the binder of waterborne inks, the capability of acrylic polymer has great influences on the quality of inks. In this contribution, structured latex particles with a poly (stryrene-butyl acrylate-methacrylate) core and a poly (butyl acrylate-methyl methacrylate-methacrylic acid-diacetone acrylamide (DAAM)) shell, which can be used as binders of water-based ink, were prepared by emulsion polymerization. The emulsion can cure in the course of film forming at ambient temperature through the reaction between DAAM and the adipic acid dihydrazide (ADH). Fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC), transmission electron microscopy (TEM), atomic force microscopy (AFM) were used to characterize the structures and study the properties of the latices. The drying time of the crosslinking latices was investigated. In addition, influences of DAAM monomer dosage and the mole ratio of DAAM to ADH on the mechanical properties of self-crosslinkable core-shell latices were also discussed. It was found that the core-shell crosslinkable particles with a low glass transition temperature (Tg) core and a high Tg shell have better film properties and would be more applicable to binders of water-based ink for plastic film, in comparison with those particles with a high Tg core and a low Tg shell.

Synthesis of high viscosity index base stock and study on the lubricating properties

2016 ◽  
Vol 68 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Weiwei Wang ◽  
Shan Jiang ◽  
Yan Shen ◽  
Shunba Xia ◽  
Jiujun Xu
Keyword(s):  
Ionic Liquid ◽  
Reaction Time ◽  
Viscosity Index ◽  
Content Type ◽  
Group I ◽  
Film Forming ◽  
Wide Range ◽  
Catalyst Dosage ◽  
Group Ii ◽  
Lubricating Properties

Purpose – This paper aims to address the polymerization of 1-decene by [Emim]Cl/AlCl3 ionic liquid and the film-forming properties of the product compared with commercially available base stocks. Design/methodology/approach – Experiments were carried out to investigate the influence of [Emim]Cl/AlCl3 mole ratio, catalyst dosage, reaction temperature, reaction time and water on the polyreaction. Poly alpha-olefin (PAO) is prepared under optimal reaction condition. Film-forming properties of PAO have been compared with those of Group I, Group II and Group III base stocks, which are selected with approximately the same viscosity. Findings – Experimental results show that after a 4-h reaction time, yield of PAO can be higher than 85 per cent and viscosity index can be up to 160 with [Emim] Cl/AlCl3 mole ratio of 2:1, catalyst dosage of 3 per cent wt. and water content of 20 ppm. A strong influence of water on reaction is observed. With approximately the same viscosity, PAO shows the superiority in film thickness at low-sliding speeds compared with Group I and Group II base stocks. At high temperature, PAO provides a thicker film than other base stocks. Originality/value – In recent years, there has been considerable interest in ionic liquids. As a novel catalyst, it has so many advantages including low corrosion, low toxicity, low cost and a potentially wide range of properties compared with traditional catalysts. This paper reports the polymerization of 1-decene by [Emim]Cl/AlCl3 ionic liquid and the study on lubricating properties of PAO compared with mineral base stocks.

Soft EHL Lubrication of Complex Multiphase Fluids

2005 ◽  
Author(s):  
J. de Vicente ◽  
H. A. Spikes ◽  
J. R. Stokes
Keyword(s):  
Complex Fluids ◽  
Steel Ball ◽  
Film Forming ◽  
Wide Range ◽  
Multiphase Fluids ◽  
Water Based ◽  
Complex Rheology ◽  
Lubrication Properties ◽  
Flat Contact ◽  
Ehl Lubrication

The lubrication properties of a series of multiphase water-based fluids of complex rheology and microstructure, including o/w emulsions, have been studied in a rolling-sliding steel ball-on-elastomer flat contact. The results show that friction curves of Newtonian fluids made over a wide range of entrainment speeds and viscosity can be used to identify the prevailing mechanisms of lubrication for more complex fluids and, for emulsions, to show the predominant film-forming phase.

scholarly journals Psychology, Meaning Making, and the Study of Worldviews

2018 ◽  
Author(s):  
Ann Taves ◽  
Egil Asprem ◽  
Elliott Daniel Ihm
Keyword(s):  
Meaning Making ◽  
Sense Making ◽  
Evolutionary Perspective ◽  
Cognitive Level ◽  
Multidisciplinary Study ◽  
Human Ability ◽  
Wide Range ◽  
Object Of Study ◽  
Different Levels ◽  
Ways Of Life

To get beyond the solely negative identities signaled by atheism and agnosticism, we have to conceptualize an object of study that includes religions and non-religions. We advocate a shift from “religions” to “worldviews” and define worldviews in terms of the human ability to ask and reflect on “big questions” ([BQs], e.g., what exists? how should we live?). From a worldviews perspective, atheism, agnosticism, and theism are competing claims about one feature of reality and can be combined with various answers to the BQs to generate a wide range of worldviews. To lay a foundation for the multidisciplinary study of worldviews that includes psychology and other sciences, we ground them in humans’ evolved world-making capacities. Conceptualizing worldviews in this way allows us to identify, refine, and connect concepts that are appropriate to different levels of analysis. We argue that the language of enacted and articulated worldviews (for humans) and world-making and ways of life (for humans and other animals) is appropriate at the level of persons or organisms and the language of sense making, schemas, and meaning frameworks is appropriate at the cognitive level (for humans and other animals). Viewing the meaning making processes that enable humans to generate worldviews from an evolutionary perspective allows us to raise news questions for psychology with particular relevance for the study of nonreligious worldviews.

scholarly journals Formulation, Development and Evaluation of Bilayer Floating Tablet of Gemfibrozil

2019 ◽  
Vol 9 (4) ◽  
pp. 574-578
Author(s):  
Mohammad Faizan Mohammad Gufran ◽  
Sailesh Kumar Ghatuary ◽  
Reena Shende ◽  
Prabhat Kumar Jain ◽  
Geeta Parkhe
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Hydroxypropyl Methylcellulose ◽  
Immediate Release ◽  
In Vitro Dissolution ◽  
Log P ◽  
Physical Parameters ◽  
Direct Compression ◽  
Formulation Development ◽  
Compression Technique

Formulation development is an important part of drug design and development. Bioavailability and bioequivalence are totally dependent on formulation development. Now-a-days formulation development is done by following QbD (Quality by Design).The aim of present study is to formulate Gemfibrozil (Gem) sustained release (SR) and immediate release (IR) bilayer tablet by different concentration of Hydroxypropyl methylcellulose (HPMC) and HPMC K 100 M to control the release pattern. The sustained release layer of Gem was prepared by using different grades of HPMC like, HPMC K-15, HPMC K-4 along with other excipients by direct compression technique. The immediate release layer of Gem was prepared by Cross carmellose sodium, Crospovidone and Sodium starch glycolate by direct compression technique. The powders were evaluated for their flow properties and the finished tablets were evaluated for their physical parameters. The both immediate release and sustained release layers of Gem were characterized by FT-IR and in vitro dissolution studies. The drug release study of Gem was evaluated using USP-II paddle type dissolution apparatus. The release rate of Gem in immediate release layer was studied for 15 min in 0.1 N HCL media and that of Gem in sustained release layer was studied for 12 h in 0.1 N HCL. From the nine batches F6 batch showed good release behaviour 99.85% of drug is released over 12 hours. Gem belongs to BCS Class II (log P 3.6) with poor solubility and high permeability resulting in limited and variable bioavailability. Total four trial batches of each drug have been manufactured to optimize and develop a robust and stable formulation, the stability studies of the products also comply with ICH guideline. Keywords: Bilayer floating tablets, Gemfibrozil, Biphasic drug release, HPMC K 15.

Stomatal Development During Leaf Expansion in Tobacco and Sunflower

1975 ◽  
Vol 23 (2) ◽  
pp. 253 ◽  
Author(s):  
HM Rawson ◽  
CL Craven
Keyword(s):  
Leaf Area ◽  
Stomatal Density ◽  
Stomatal Development ◽  
Developmental Patterns ◽  
Full Size ◽  
Unit Leaf Area ◽  
Unit Leaf ◽  
Wide Range ◽  
Young Leaves ◽  
Different Levels

Changes in stomatal density and size were followed in tobacco and sunflower leaves expanding from 10% of final area (10% Amax) to Amax under different levels of radiation. Lower radiation increased final leaf area, reduced stomatal densities, and increased area per stoma but had little effect on stomatal area per unit leaf area at Amax. In very young leaves (20% Amax) there was a wide range in the sizes of individual stomata, some stomata being close to full size, but by Amax differences were small. The possible relationship between the developmental patterns described and photosynthesis is briefly discussed.

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