Influence of emulsification mode, stirring speed and volume on ibuprofen-loaded PLGA microparticles

2021 ◽  
Vol 70 (1) ◽  
pp. 32-40
Author(s):  
Holická Martina ◽  
Muselík Jan ◽  
Kubová Kateřina ◽  
Deáková Veronika ◽  
Pavloková Sylvie ◽  
...  

Microparticles based on biodegradable synthetic lactic acid and glycolic acid copolymer (PLGA) were successfully prepared by the solvent evaporation method. Ibuprofen was chosen as the model drug. Various formulation and process parameters have been used to prepare each sample with emphasis on size reduction. The effect of the emulsification method (direct emulsification or emulsification using an ULTRA-TURRAX or a NE-1000 dispenser), the volume of the aqueous phase (200, 800 ml) and the stirring speed of the emulsion system (600, 1000 rpm) on the characteristic properties of microparticles, such as encapsulation efficiency, drug loading and particle morphology, was observed. The resulting microparticles were evaluated by optical microscopy or laser diffraction and the dissolution test was performed. It was found that the sample prepared by direct emulsification with 800 ml of an aqueous phase at 600 rpm provided the most favorable results, meanwhile the emulsification pre-step using a homogenizer caused promising particle size reduction. Gradual emulsification was evaluated as inapplicable due to great losses.

2018 ◽  
Vol 60 (1) ◽  
pp. 42-45
Author(s):  
Tuan Quang Nguyen ◽  
Van Lam Nguyen ◽  
Thai Son Nguyen ◽  
Thi Minh Hue Pham ◽  
◽  
...  

Author(s):  
Nagda C. D. ◽  
Chotai N. P. ◽  
Patel S. B. ◽  
Soni T. J ◽  
Patel U. L

Aceclofenac (ACE) is NSAIDs of a phenyl acetic acid class. It is indicated in arthritis and osteoarthritis, rheumatoid arthritis, ankylosing spondylitis. It has short elimination half life of 4 hours. The objective of the study is to design, characterize and evaluate bioadhesive microspheres of ACE employing carbopol (CP) as bioadhesive polymer. Bioadhesive microspheres of ACE were prepared by solvent evaporation method. The prepared microspheres were free flowing and spherical in shape and characterized for drug loading, mucoadhesion test, infrared spectroscopy (IR), differential scanning colorimetry (DSC) and scanning electron microscopy (SEM). The in-vitro release studies were performed using pH 6.8 phosphate buffer. The drug loaded microspheres in a ratio of 1:5 showed 47% of drug entrapment; percentage mucoadhesion was 81% and 89% release in 10 h. The infrared spectra and DSC showed stable character of aceclofenac in the drug loaded microspheres and revealed the absence of drug-polymer interactions. SEM studies showed that the microspheres are spherical and porous in nature. The in vitro release profiles from microspheres of different polymer-drug ratios followed Higuchi model.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shaobin Zhang ◽  
Claudia Contini ◽  
James W. Hindley ◽  
Guido Bolognesi ◽  
Yuval Elani ◽  
...  

AbstractThere are increasing efforts to engineer functional compartments that mimic cellular behaviours from the bottom-up. One behaviour that is receiving particular attention is motility, due to its biotechnological potential and ubiquity in living systems. Many existing platforms make use of the Marangoni effect to achieve motion in water/oil (w/o) droplet systems. However, most of these systems are unsuitable for biological applications due to biocompatibility issues caused by the presence of oil phases. Here we report a biocompatible all aqueous (w/w) PEG/dextran Pickering-like emulsion system consisting of liposome-stabilised cell-sized droplets, where the stability can be easily tuned by adjusting liposome composition and concentration. We demonstrate that the compartments are capable of negative chemotaxis: these droplets can respond to a PEG/dextran polymer gradient through directional motion down to the gradient. The biocompatibility, motility and partitioning abilities of this droplet system offers new directions to pursue research in motion-related biological processes.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 971
Author(s):  
Oktawian Bialas ◽  
Mateusz Lis ◽  
Anna Woźniak ◽  
Marcin Adamiak

This paper analyses the possibility of obtaining surface-infused nano gold particles with the polyether ether ketone (PEEK) using picosecond laser treatment. To fuse particles into polymer, the raw surface of PEEK was sputtered with 99.99% Au and micromachined by an A-355 laser device for gold particle size reduction. Biomimetic pattern and parameters optimization were key properties of the design for biomedical application. The structures were investigated by employing surface topography in the presence of micron and sub-micron features. The energy of the laser beam stating the presence of polymer bond thermalisation with remelting due to high temperature was also taken into the account. The process was suited to avoid intensive surface modification that could compromise the mechanical properties of fragile cardiovascular devices. The initial material analysis was conducted by power–depth dependence using confocal microscopy. The evaluation of gold particle size reduction was performed with scanning electron microscopy (SEM), secondary electron (SE) and quadrant backscatter electron detector (QBSD) and energy dispersive spectroscopy (EDS) analysis. The visibility of the constituted coating was checked by a commercial grade X-ray that is commonly used in hospitals. Attempts to reduce deposited gold coating to the size of Au nanoparticles (Au NPs) and to fuse them into the groove using a laser beam have been successfully completed. The relationship between the laser power and the characteristics of the particles remaining in the laser irradiation area has been established. A significant increase in quantity was achieved using laser power with a minimum power of 15 mW. The obtained results allowed for the continuation of the pilot study for augmented research and material properties analysis.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2856
Author(s):  
Gary B. Smejkal ◽  
Edmund Y. Ting ◽  
Karthik Nambi Arul Nambi ◽  
Richard T. Schumacher ◽  
Alexander V. Lazarev

Stable, oil-in-water nanoemulsions containing astaxanthin (AsX) were produced by intense fluid shear forces resulting from pumping a coarse reagent emulsion through a self-throttling annular gap valve at 300 MPa. Compared to crude emulsions prepared by conventional homogenization, a size reduction of over two orders of magnitude was observed for AsX-encapsulated oil droplets following just one pass through the annular valve. In krill oil formulations, the mean hydrodynamic diameter of lipid particles was reduced to 60 nm after only two passes through the valve and reached a minimal size of 24 nm after eight passes. Repeated processing of samples through the valve progressively decreased lipid particle size, with an inflection in the rate of particle size reduction generally observed after 2–4 passes. Krill- and argan oil-based nanoemulsions were produced using an Ultra Shear Technology™ (UST™) approach and characterized in terms of their small particle size, low polydispersity, and stability.


Crystals ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 249 ◽  
Author(s):  
Zhen-Yu Yang ◽  
Shih-Kuo Yen ◽  
Wei-Syun Hu ◽  
Yu-Zhe Huang ◽  
Tsung-Mao Yang ◽  
...  

1996 ◽  
Vol 18 (2) ◽  
pp. 121-125 ◽  
Author(s):  
M.P. Nandakumar ◽  
M.S. Thakur ◽  
K.S.M.S. Raghavarao ◽  
N.P. Ghildyal

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