Effect of Physical Properties and Emulsification Conditions on the Microsphere Size Prepared Using a Solvent Extraction Process

Heiskanen, Harri; Denifl, Peter; Hurme, Markku; Pitkänen, Päivi; Oksman, Marita

doi:10.1080/01932691.2011.561166

Cited by 13 publications

(4 citation statements)

References 18 publications

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“…While an increase in the organic/aqueous phase volume ratio has been shown to increase the number of particles generated, this effect also leads to a size increase of particles, as supported by our data ( Figure 7 and Figure 8 F) and others [ 20 , 43 ]. As opposed to this, the concentration of surfactant (PVA) and the stirring rate of the emulsion have both been identified to have an inverse correlation to particle size (20, 27–31).…”

Section: Resultssupporting

confidence: 90%

Fabrication of PEG-PLGA Microparticles with Tunable Sizes for Controlled Drug Release Application

Sagoe,

Velázquez,

Espiritusanto

et al. 2023

Molecules

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Polymeric microparticles of polyethyleneglycol-polylactic acid-co-glycolic acid (PEG-PLGA) are widely used as drug carriers for a variety of applications due to their unique characteristics. Although existing techniques for producing polymeric drug carriers offer the possibility of achieving greater production yield across a wide range of sizes, these methods are improbable to precisely tune particle size while upholding uniformity of particle size and morphology, ensuring consistent production yield, maintaining batch-to-batch reproducibility, and improving drug loading capacity. Herein, we developed a novel scalable method for the synthesis of tunable-sized microparticles with improved monodispersity and batch-to-batch reproducibility via the coaxial flow-phase separation technique. The study evaluated the effect of various process parameters on microparticle size and polydispersity, including polymer concentration, stirring rate, surfactant concentration, and the organic/aqueous phase flow rate and volume ratio. The results demonstrated that stirring rate and polymer concentration had the most significant impact on the mean particle size and distribution, whereas surfactant concentration had the most substantial impact on the morphology of particles. In addition to synthesizing microparticles of spherical morphology yielding particle sizes in the range of 5–50 µm across different formulations, we were able to also synthesize several microparticles exhibiting different morphologies and particle concentrations as a demonstration of the tunability and scalability of this method. Notably, by adjusting key determining process parameters, it was possible to achieve microparticle sizes in a comparable range (5–7 µm) for different formulations despite varying the concentration of polymer and volume of polymer solution in the organic phase by an order of magnitude. Finally, by the incorporation of fluorescent dyes as model hydrophilic and hydrophobic drugs, we further demonstrated how polymer amount influences drug loading capacity, encapsulation efficiency, and release kinetics of these microparticles of comparable sizes. Our study provides a framework for fabricating both hydrophobic and hydrophilic drug-loaded microparticles and elucidates the interplay between fabrication parameters and the physicochemical properties of microparticles, thereby offering an itinerary for expanding the applicability of this method for producing polymeric microparticles with desirable characteristics for specific drug delivery applications.

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Section: Resultssupporting

confidence: 90%

Fabrication of PEG-PLGA Microparticles with Tunable Sizes for Controlled Drug Release Application

Sagoe,

Velázquez,

Espiritusanto

et al. 2023

Molecules

View full text Add to dashboard Cite

show abstract

“…An increase in surfactant concentration from 1.0% (F8) to 1.5% (F3) to 2.0% (F9) (w/v) resulted in a reduction in the mean particle size of the microspheres from 989.7 to 844.4 μm. The presence of surfactant in the external oil phase stabilizes emulsion droplets against coalescence, resulting in smaller emulsion droplets and therefore producing smaller microspheres ( Table 2 ) ( 27 28 ).…”

Section: Discussionmentioning

confidence: 99%

Preparation and characterization of ethylcellulose microspheres for sustained-release of pregabalin

Yasin

Al-Taani

Salem

2021

Research in Pharmaceutical Sciences

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Background and purpose: Pregabalin is used in the treatment of epilepsy, chronic pain, and other psychological disorders. Preparation of pregabalin in the sustained-release formulation will enhance patient compliance and reduce the incidence of side effects. The aim of this study was to prepare sustained-release microspheres for pregabalin utilizing ethylcellulose and evaluate the processing factors that influence the fabrication and the performance of the prepared microspheres. Experimental approach: The microspheres were prepared using the water-oil-oil double emulsion solvent evaporation method. Microspheres were characterized for particle size, encapsulation efficiency, and in vitro drug release. The influence of the processing variables on the characteristics of the prepared microspheres was studied. Microspheres solid-state characterization performed using differential scanning calorimetry, Fourier transform infrared spectroscopy and scanning electron microscopy. Findings/Results: The results described in the context of the current work illustrated the suitability of the water-oil-oil system in the preparation of sustained-release microspheres for pregabalin. The optimum formulation was prepared at a drug to polymer ratio of 1:3 w/w, stirring speed of 600 rpm, surfactant concentration of 1.5%, and external phase volume of 150 mL. This formula produced microspheres particle size in the range 600-1000 μm, with 87.6% yield, and 80.14 ± 0.53% encapsulation efficiency. Drug release from the microspheres was found to be diffusion controlled, with a pH-independent behavior. Conclusion and implication The current work presented a successful attempt to fabricate a sustained-release microsphere comprising pregabalin. This will help overcome the frequent dosing problems with conventional pregabalin dosage forms and improve product performance.

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“…Increased continuous phase viscosity reduced the coalescence of the droplets and hence smaller microspheres were produced. The mean microsphere size was first found to decrease as the volume ratio of the dispersed phase to the continuous phase increased but upon further increase, the mean microsphere size was found to increase [99].…”

Section: Effect Of Viscosity Of the Dispersed And Continuous Phase Onmentioning

confidence: 98%

Study of Effect of Different Factors in Formulation of Micro and Nanospheres with Solvent Evaporation Technique

Subedi¹,

Shrestha²,

Shakya³

2016

PHARMSCI

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Background: There are various methods of formulation of micro and nanospheres such as solvent evaporation, solvent removal, polymerization, hot-melt encapsulation, coacervation, phase/wet inversion, spray drying, spray congealing etc. Amongst these all, solvent evaporation is one of the most widely used, researched, easy, accessible methods and for which many patents have been applied. It is thus imperative to understand the basics of effect of formulation variables and design of solvent evaporation method which will be covered in this review article. Objective: To discuss the various formulation factors while designing the robust micro and nanospherical systems with better morphology, entrapment and release of the drugs. Method: Systematic analysis of the relevant literature, bibliographies, and interactions with investigators. Results: From the investigation of different literatures, it was found that various factors of solvent evaporation technique may be controlled in order to design the micro and nanospheres of suitable morphology, entrapment and release characters. Conclusion: Various factors like type of polymer used, weight, viscosity, hydrophilicity, concentration, polymer ratio, stirring speed, emulsifier concentration, concentration of cross-linking agents, type of solvent used, rate of addition of solvent etc. Affect the yield, morphology, release and entrapment of the drug inside the system. Hence, these factors play crucial role in the design of a robust micro and nanospherical system.

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Effect of Physical Properties and Emulsification Conditions on the Microsphere Size Prepared Using a Solvent Extraction Process

Cited by 13 publications

References 18 publications

Fabrication of PEG-PLGA Microparticles with Tunable Sizes for Controlled Drug Release Application

Fabrication of PEG-PLGA Microparticles with Tunable Sizes for Controlled Drug Release Application

Preparation and characterization of ethylcellulose microspheres for sustained-release of pregabalin

Study of Effect of Different Factors in Formulation of Micro and Nanospheres with Solvent Evaporation Technique

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