Metal release from stainless steel particles in vitro—influence of particle size

2007 ◽  
Vol 9 (1) ◽  
pp. 74-81 ◽  
Author(s):  
K. Midander ◽  
J. Pan ◽  
I. Odnevall Wallinder ◽  
C. Leygraf
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Metal Release

Pyrolysis of brown algae (Bifurcaria Bifurcata) in a stainless steel tubular reactor: From a review to a case study

2018 ◽  
Vol 14 (1) ◽  
pp. 31-60 ◽  
Author(s):  
M. Y. Guida ◽  
F. E. Laghchioua ◽  
A. Hannioui
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Flow Rate ◽  
Brown Algae ◽  
Tubular Reactor ◽  
Nitrogen Flow ◽  
Nitrogen Flow Rate ◽  
Bifurcaria Bifurcata ◽  
Bio Oil

This article deals with fast pyrolysis of brown algae, such as Bifurcaria Bifurcata at the range of temperature 300–800 °C in a stainless steel tubular reactor. After a literature review on algae and its importance in renewable sector, a case study was done on pyrolysis of brown algae especially, Bifurcaria Bifurcata. The aim was to experimentally investigate how the temperature, the particle size, the nitrogen flow rate (N2) and the heating rate affect bio-oil, bio-char and gaseous products. These parameters were varied in the ranges of 5–50 °C/min, below 0.2–1 mm and 20–200 mL. min–1, respectively. The maximum bio-oil yield of 41.3wt% was obtained at a pyrolysis temperature of 600 °C, particle size between 0.2–0.5 mm, nitrogen flow rate (N2) of 100 mL. min–1 and heating rate of 5 °C/min. Liquid product obtained under the most suitable and optimal condition was characterized by elemental analysis, 1H-NMR, FT-IR and GC-MS. The analysis of bio-oil showed that bio-oil from Bifurcaria Bifurcata could be a potential source of renewable fuel production and value added chemicals.

Formulation and Evaluation of Mefloquine Hydrochloride Nanoparticles

2014 ◽  
Vol 7 (1) ◽  
pp. 2377-2386
Author(s):  
Dilip Kumar Gupta ◽  
B K Razdan ◽  
Meenakshi Bajpai
Keyword(s):  
Particle Size ◽  
Sustained Release ◽  
In Vitro Release ◽  
Entrapment Efficiency ◽  
Taste Masking ◽  
Diffusion Method ◽  
Drug Entrapment Efficiency ◽  
Resistant Strains ◽  
Vitro Release

The present study deals with the formulation and evaluation of mefloquine hydrochloride nanoparticles. Mefloquine is a blood schizonticidal quinoline compound, which is indicated for the treatment of mild-to-moderate acute malarial infections caused by mefloquine-susceptible multi-resistant strains of P. falciparum and P. vivax. The purpose of the present work is to minimize the dosing frequency, taste masking toxicity and to improve the therapeutic efficacy by formulating mefloquine HCl nanoparticles. Mefloquine nanoparticles were formulated by emulsion diffusion method using polymer poly(ε-caprolactone) with six different formulations. Nanoparticles were characterized by determining its particle size, polydispersity index, drug entrapment efficiency, drug content, particle morphological character and drug release. The particle size ranged between 100 nm to 240 nm. Drug entrapment efficacy was >95%. The in-vitro release of nanoparticles were carried out which exhibited a sustained release of mefloquine HCl from nanoparticles up to 24 hrs. The results showed that nanoparticles can be a promising drug delivery system for sustained release of mefloquine HCl.

Preparation, Characterization and In-vitro release of Piroxicam-loaded Solid Lipid Nanoparticles

2010 ◽  
Vol 3 (3) ◽  
pp. 1136-1146
Author(s):  
V K Verma ◽  
Ram A
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Solid Lipid Nanoparticles ◽  
In Vitro Release ◽  
Entrapment Efficiency ◽  
Lipid Nanoparticles ◽  
Diffusion Method ◽  
Solid Lipid ◽  
Vitro Release

 Solid lipid nanoparticles (SLNs) of piroxicam where produced by solvent emulsification diffusion method in a solvent saturated system. The SLNs where composed of tripamitin lipid, polyvinyl alcohol (PVAL) stabilizer, and solvent ethyl acetate. All the formulation were subjected to particle size analysis, zeta potential, drug entrapment efficiency, percent drug loading determination and in-vitro release studies. The SLNs formed were nano-size range with maximum entrapment efficiency. Formulation with 435nm in particle size and 85% drug entrapment was subjected to scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for surface morphology, differential scanning calorimetry (DSC) for thermal analysis and short term stability studies. SEM and TEM confirm that the SLNs are nanometric size and circular in shape. The drug release behavior from SLNs suspension exhibited biphasic pattern with an initial burst and prolong release over 24 h. 

Solid Lipid Nanoparticles for Topical Delivery of Acitretin for the Treatment of Psoriasis by Design of Experiment

2020 ◽  
Vol 12 (2) ◽  
pp. 4474-4491
Author(s):  
Rajkumar Aland ◽  
Ganesan M ◽  
P. Rajeswara Rao ◽  
Bhikshapathi D. V. R. N.
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Solid Lipid Nanoparticles ◽  
Drug Loading ◽  
Entrapment Efficiency ◽  
Lipid Nanoparticles ◽  
Tem Analysis ◽  
In Vitro Drug Release ◽  
Solid Lipid

The main objective for this investigation is to develop and optimize the solid lipid nanoparticles formulation of acitretin for the effective drug delivery. Acitretin loaded SLNs were prepared by hot homogenization followed by the ultrasonication using Taguchi’s orthogonal array with eight parameters that could affect the particle size and entrapment efficiency. Based on the results from the analyses of the responses obtained from Taguchi design, three different independent variables including surfactant concentration (%), lipid to drug ratio (w/w) and sonication time (s) were selected for further investigation using central composite design. The  lipid Dynasan-116, surfactant poloxomer-188 and co surfactant egg lecithin resulted in better percent drug loading and evaluated for particle size, zeta potential, drug entrapment efficiency, in vitro drug release and stability. All parameters were found to be in an acceptable range. TEM analysis has demonstrated the presence of individual nanoparticles in spherical shape and the results were compatible with particle size measurements.  In vitro drug release of optimized SLN formulation (F2) was found to be 95.63 ± 1.52%, whereas pure drug release was 30.12 after 60 min and the major mechanism of drug release follows first order kinetics release data for optimized formulation (F2) with non-Fickian (anomalous) with a strong correlation coefficient (R2 = 0.94572) of Korsemeyer-Peppas model. The total drug content of acitretin gel formulation was found to 99.86 ± 0.012% and the diameter of gel formulation was 6.9 ± 0.021 cm and that of marketed gel was found to be 5.7 ± 0.06 cm, indicating better spreadability of SLN based gel formulation. The viscosity of gel formulation at 5 rpm was found to be 6.1 x 103 ± 0.4 x 103 cp. The release rate (flux) of acitretin across the membrane and excised skin differs significantly, which indicates about the barrier properties of skin. The flux value for SLN based gel formulation (182.754 ± 3.126 μg cm−2 h−1) was found to be higher than that for marketed gel (122.345 ± 4.786 μg cm−2 h−1). The higher flux and Kp values of SLN based gel suggest that it might be able to enter the skin easily as compared with marketed gel with an advantage of low interfacial tension of the emulsifier film that ensures an excellent contact to the skin. This topically oriented SLN based gel formulation could be useful in providing site-specific dermal treatment of psoriasis

Development and Ex-vivo Evaluation of Topiramate Mucoadhesive Nanoparticles for Intranasal Delivery

2020 ◽  
Vol 13 (6) ◽  
pp. 5250-5255
Author(s):  
Ashwin Kumar Tulasi ◽  
Anil Goud Kandhula ◽  
Ravi Krishna Velupula
Keyword(s):  
Particle Size ◽  
Nasal Mucosa ◽  
Intranasal Administration ◽  
Ex Vivo ◽  
Chemical Properties ◽  
Brain Targeting ◽  
Oral Tablet ◽  
Promising Alternative ◽  
Ex Vivo Permeation

Topiramate is a second-generation antiepileptic drug used in partial, generalized seizures as an oral tablet. Oral route of administration is most convenient but shows delayed absorption. Moreover, in emergency cases, parenteral administration is not possible as it requires medical assistance. Hence, the present study was aimed to develop topiramate mucoadhesive nanoparticles for intranasal administration using ionotropic gelation method. The developed nanoparticles were evaluated for physico-chemical properties like particle size, zeta potential, surface morphology, drug content, entrapment efficiency, in vitro drug release, mucoadhesive strength, and ex vivo permeation studies in excised porcine nasal mucosa. Optimized nanoparticle formulation (T9) was composed oil mucoadhesive agent (Chitosan 1% w/w), cross linking polymer (TPP) and topiramate 275mg, 100mg and 4% respectively. It showed particle size of 350nm, high encapsulation efficacy and strong mucoadhesive strength. In vitro drug diffusion of optimized formulation showed 95.12% release of drug after 180min. Ex-vivo permeation of drug across nasal mucosa was   88.05 % after 180min. Nasocilial toxicity studies showed optimized formulation did not damage the nasal mucosa. Thus, the intranasal administration of topiramate using chitosan can be a promising alternative for brain targeting and the treatment of epilepsy.

Formulation and Evaluation of Nanosuspension of Simvastatin

2015 ◽  
Vol 8 (2) ◽  
pp. 2858-2873
Author(s):  
Rupali L. Shid ◽  
Shashikant N. Dhole ◽  
Nilesh Kulkarni ◽  
Santosh L Shid
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Factorial Design ◽  
Dissolution Rate ◽  
In Vitro Dissolution ◽  
Total Drug ◽  
23 Factorial Design ◽  
Rate Of Dissolution

Poor water solubility and slow dissolution rate are issues for the majority of upcoming and existing biologically active compounds. Simvastatin is poorly water-soluble drug and its bioavailability is very low from its crystalline form. The purpose of this study wasto increase the solubility and dissolution rate of simvastatin by the  preparation of nanosuspension by emulsification solvent diffusion method at laboratory scale. Prepared nanosus-pension was evaluated for its particle size and in vitro dissolution study and characterized by zeta potential,differential scanning calorimetry (DSC) and X-Ray diffractometry (XRD), motic digital microscopy, entrapment efficiency, total drug content, saturated solubility study and in vivo study. A 23 factorial design was employed to study the effect of independent variables, amount of SLS (X1), amount of PVPK-30 (X2) and poloxamer-188 (X3) and dependent variables are total drug content and polydispersity Index. The obtained results showed that particle size (nm) and rate of dissolution has been improved when nanosuspension prepared with the higherconcentration of PVPK-30 with the higher concentration of PVP K-30 and Poloxamer-188 and lower concentration of SLS. The particle size and zeta potential of optimized formulation was found to be 258.3 nm and 23.43. The rate of dissolution of the optimized nanosuspension was enhanced (90% in 60min), relative to plain simvastatin  (21% in 60 min), mainly due to the formation of nanosized particles. These results indicate the suitability of 23 factorial  design for preparation of simvastatin loaded nano-suspension significantly improved in vitro dissolution rate and thus possibly enhance fast onset of therapeutic drug effect. In vivo study shows increase in bioavailability in nanosuspension formulation than the plain simvastatin drug.

Optimization and Characterization of Aqueous Micellar Formulations for Ocular Delivery of an Antifungal Drug, Posaconazole

2020 ◽  
Vol 26 (14) ◽  
pp. 1543-1555 ◽  
Author(s):  
Meltem E. Durgun ◽  
Emine Kahraman ◽  
Sevgi Güngör ◽  
Yıldız Özsoy
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Size Distribution ◽  
Encapsulation Efficiency ◽  
Fungal Infections ◽  
In Vitro Release ◽  
Pluronic F127 ◽  
Glycol Succinate ◽  
Vitro Release

Background: Topical therapy is preferred for the management of ocular fungal infections due to its superiorities which include overcoming potential systemic side effects risk of drugs, and targeting of drugs to the site of disease. However, the optimization of effective ocular formulations has always been a major challenge due to restrictions of ocular barriers and physiological conditions. Posaconazole, an antifungal and highly lipophilic agent with broad-spectrum, has been used topically as off-label in the treatment of ocular fungal infections due to its highly lipophilic character. Micellar carriers have the potential to improve the solubility of lipophilic drugs and, overcome ocular barriers. Objective: In the current study, it was aimed optimization of posaconazole loaded micellar formulations to improve aqueous solubility of posaconazole and to characterize the formulations and to investigate the physical stability of these formulations at room temperature (25°C, 60% RH), and accelerated stability (40°C, 75% RH) conditions. Method: Micelles were prepared using a thin-film hydration method. Pre-formulation studies were firstly performed to optimize polymer/surfactant type and to determine their concentration in the formulations. Then, particle size, size distribution, and zeta potential of the micellar formulations were measured by ZetaSizer Nano-ZS. The drug encapsulation efficiency of the micelles was quantified by HPLC. The morphology of the micelles was depicted by AFM. The stability of optimized micelles was evaluated in terms of particle size, size distribution, zeta potential, drug amount and pH for 180 days. In vitro release studies were performed using Franz diffusion cells. Results: Pre-formulation studies indicated that single D-ɑ-tocopheryl polyethylene glycol succinate (TPGS), a combination of it and Pluronic F127/Pluronic F68 are capable of formation of posaconazole loaded micelles at specific concentrations. Optimized micelles with high encapsulation efficiency were less than 20 nm, approximately neutral, stable, and in aspherical shape. Additionally, in vitro release data showed that the release of posaconazole from the micelles was higher than that of suspension. Conclusion: The results revealed that the optimized micellar formulation of posaconazole offers a potential approach for topical ocular administration.

Moxifloxacin Hydrochloride-Loaded Eudragit® RL 100 and Kollidon® SR Based Nanoparticles: Formulation, In vitro Characterization and Cytotoxicity.

2020 ◽  
Vol 23 ◽  
Author(s):  
Gülsel Yurtdaş Kırımlıoğlu ◽  
Sinan Özer ◽  
Gülay Büyükköroğlu ◽  
Yasemin Yazan
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Spray Drying ◽  
Prolonged Release ◽  
Ocular Delivery ◽  
Corneal Permeability ◽  
Release Pattern ◽  
In Vitro Characterization ◽  
Ocular Bioavailability

Background: Considering the low ocular bioavailability of conventional formulations used for ocular bacterial infection treatment, there’s a need for designing efficient novel drug delivery systems that may enhance of precorneal retention time and corneal permeability. Aim and Objective: The current research focuses on developing nanosized and non-toxic Eudragit® RL 100 and Kollidon® SR nanoparticles loaded with moxifloxacin hydrochloride (MOX) for its prolonged release to be promising for effective ocular delivery. Methods: In this study, MOX was incorporation was carried out by spray drying method aiming ocular delivery. In vitro characteristics were evaluated in detail with different methods. Results: MOX was successfully incorporated into Eudragit® RL 100 and Kollidon® SR polymeric nanoparticles by spray-drying process. Particle size, zeta potential, entrapment efficiency, particle morphology, thermal, FTIR, XRD and NMR analyses and MOX quantification using HPLC method were carried out to evaluate the nanoparticles prepared. MOX loaded nanoparticles demonstrated nanosized and spherical shape while in vitro release studies demonstrated modified release pattern which followed Korsmeyer-Peppas kinetic model. Following successful incorporation of MOX into the nanoparticles, the formulation (MOX: Eudragit® RL 100, 1:5) (ERL-MOX 2) was selected for further studies by the reason of its better characteristics like cationic zeta potential, smaller particle size, narrow size distribution and more uniform prolonged release pattern. Moreover, ERL-MOX 2 formulation remained stable for 3 months and demonstrated higher cell viability values for MOX. Conclusion: In vitro characterization analyses showed that non-toxic, nano-sized and cationic ERLMOX 2 formulation has the potential of enhancing ocular bioavailability.

In Vitro Estimation of Photo-Protective Potential of Pomegranate Seed Oil and Development of a Nanoformulation

2019 ◽  
Vol 15 (1) ◽  
pp. 87-102 ◽  
Author(s):  
Surbhi Dhawan ◽  
Sanju Nanda
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Seed Oil ◽  
Topical Delivery ◽  
Inflammatory Activity ◽  
Pomegranate Seed Oil ◽  
Protective Potential ◽  
Release Studies ◽  
Pomegranate Seed

Background: Since ancient times, people have been using natural resources for photoprotection purposes. One such highly recognised natural agent is pomegranate seed oil, considered as wonder oil owing to the presence of several beneficial phytoconstituents. </P><P> Objective: The study aimed to establish the photoprotective potential of pomegranate seed oil through various in vitro and biochemical studies along with the formation of nanoemulsion, an efficient topical delivery system for the oil. </P><P> Method: Photo-protective potential of the oil was estimated by determining in vitro antioxidant and anti-inflammatory activity, total phenolic content, anti elastase, antihyaluronidase and anticollagenase activities of the oil. Ultrasonication method was used to formulate nanoemulsions. The optimisation was done following the central composite design. The characterisation was done by particle size analysis, zeta potential, polydispersity index, pH, viscosity, stability testing and transmission electron microscopy. The optimised nanoemulsion was loaded into a gel base for topical application and further release studies were carried out. </P><P> Results: The IC50 values of anti-elastase, anti-collagenase and anti-hyaluronidase were found to be 309 mg/ml, 4 mg/ml and 95 mg/ml respectively. The results of anti-oxidant and anti-inflammatory activity were also significant, which thereby established the photo-protective potential of the oil. The optimum batch 2 had particle size 83.90 nm, 0.237 PDI and -5.37 mV zeta potential. The morphology was confirmed by TEM. Batch 2 was incorporated into a gel base and release studies showed 74.12 % release within 7 hours. </P><P> Conclusion: Pomegranate seed oil possesses a potential photo-protective ability. Nanoemulsions proved to be a promising carrier for the topical delivery of the oil.

Design and Evaluation of Long Acting Biodegradable PLGA Microspheres for Ocular Drug Delivery

2019 ◽  
Vol 10 ◽  
Author(s):  
Anjali Pandya ◽  
Rajani Athawale ◽  
Durga Puro ◽  
Geeta Bhagwat
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Degradation Products ◽  
Ex Vivo ◽  
Research Work ◽  
Entrapment Efficiency ◽  
Rational Approach ◽  
Plga Microspheres ◽  
Long Acting

Background: The research work involves development of PLGA biodegradable microspheres loaded with dexamethasome for intraocular delivery. Objective: To design and evaluate long acting PLGA microspheres for ocular delivery of dexamethasone. Method: Present formulation involves the development of long acting dexamethasone loaded microspheres composed of a biodegradable controlled release polymer, Poly(D, L- lactide-co-glycolide) (PLGA), for the treatment of posterior segment eye disorders intravitreally. PLGA with monomer ratio of 50:50 of lactic acid to glycolic acid was used to achieve a drug release up to 45 days. Quality by Design approach was utilized for designing the experiments. Single emulsion solvent evaporation technique along with high pressure homogenization was used to facilitate formation of microspheres. Results: Particle size evaluation, drug content and drug entrapment efficiency were determined for the microspheres. Particle size and morphology was observed using Field Emission Gun-Scanning Electron Microscopy (FEG-SEM) and microspheres were in the size range of 1-5 μm. Assessment of drug release was done using in vitro studies and transretinal permeation was observed by ex vivo studies using goat retinal tissues. Conclusion: Considering the dire need for prolonged therapeutic effect in diseases of the posterior eye, an intravitreal long acting formulation was designed. Use of biodegradable polymer with biocompatible degradation products was a rational approach to achieve this aim. Outcome from present research shows that developed microspheres would provide a long acting drug profile and reduce the frequency of administration thereby improving patient compliance.

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