The effect of process parameters on the size and morphology of poly(D,L‐lactide‐co‐glycolide) micro/nanoparticles prepared by an oil in oil emulsion/solvent evaporation technique

Abstract

For the past few decades, there has been a considerable research interest in the area of biodegradable polymeric micro-and nanoparticles for tissue engineering, regenerative medicine, implants, stents, medical devices, and drug delivery systems. Poly(D,L-lactide-coglycolide) (PLGA) is well-known by its safety in biomedical preparations which has been approved for human use by the FDA. The goal of this study was to evaluate the influence of process parameters on size characteristics of PLGA microparticles prepared by oil in oil (o/o) solvent evaporation technique. This method has been introduced as one of the most appropriate methods for hydrophilic agents. Scanning electron microscopy showed that prepared particles were spherical with smooth surface without aggregation. Particle size varied from 570 nm to 29 lm in different experimental conditions. Stirring speed, polymer concentration, impeller type, and dropping size had a significant effect on the particle size. The polydispersity index of particles showed a strong relationship with the surfactant concentration, impeller type, and dropping size. It was concluded that increasing in temperature up to 50 C or changing in dropping rate has a little effect on reducing the size of PLGA particles. The residual solvent content in the final suspension was less than 0.1 ppm that is in appropriate range for biomedical application.

Improved drug loading and antibacterial activity of minocycline-loaded PLGA nanoparticles prepared by solid/oil/water ion pairing method

“…This was contributed to by the liquid paraffin used as a continuation phase with this method. 42 The limited solubility of minocycline and nil diffusion of first oil into liquid paraffin were advantageous to restrict minocycline leakage in comparison with other aqueous solvent diffusion methods. Polymeric particles obtained by this method had the largest particle size.…”

“…42 Drug and polymer solution was prepared by dissolving 7.5 mg of minocycline and 37.5 mg PLGA 504H in 3 mL of acetonitrile. This solution was added into 40 mL of viscous liquid paraffin containing 200 µL Span 80 and continuously stirred, yielding a finely dispersed drug suspension.…”

“…The drug encapsulation efficiency was determined from the mass ratio of the encapsulated drug to the amount of drug initially added. The amount of drug loading and encapsulation efficiency were calculated using the following equations: 42 Drug loading (%) = (minocycline weight in sample/total weight of sample) × 100% Encapsulation efficiency = (actual/theoretical minocycline loading) × 100%…”

Enhanced in Vitro Anti-Tumor Activity of 5-Azacytidine by Entrapment into Solid Lipid Nanoparticles

“…However, these explored nanoparticulate delivery systems demonstrate their own disadvantages. Commonly reported drawbacks of colloidal carriers such as liposomes, nanosponges, microemulsions and nanoemulsions, polymeric nanoparticles, and nanocapsules are burst drug release, physical and chemical instability during storage, [20][21][22][23] difficulty in industrial fabrication, the presence of organic solvents applied in the production of these systems, some limitations in polymer toxicity 24,25 and many more too numerous to mention. All of these disadvantages suggest that these colloidal drug delivery systems are not perfect.…”

Polímeros sintéticos biodegradáveis: matérias-primas e métodos de produção de micropartículas para uso em drug delivery e liberação controlada

“…A emulsificação extração e/ou evaporação do solvente do meio de emulsões do tipo O/O constitui um método particularmente apropriado para incorporar princípios ativos hidrossolúveis em polímeros hidrofóbicos, obtendo-se microsferas [52,54] . Inicialmente, o polímero é dissolvido num solvente orgânico polar, por exemplo, a acetona, o metanol ou a acetonitrila [10,11] , constituindo a fase interna, na qual é dissolvida ou dispersa princípios ativos.…”