Separation of drug-loaded nanoparticles from free drug by gel filtration

Abstract

A suitable method for separating free drug and other residual compounds from drug-loaded, colloidal polymeric particles was developed. The objective of this separation procedure was to purify particle suspensions on a preparative scale by a rapid, simple, and exact method without changing the properties of the particles. The gel filtration method described in this paper using a middle-pressure chromatographic system is able to meet all these requirements. The separation process could be optimized by using only water as an eluent in combination with Sephadex G 50 medium. The purified particles appeared after 12-13 min in the eluate. Neither dispersity nor particle size or loading rate were influenced to a considerable extent.

Methods for the Preparation and Manufacture of Polymeric Nanoparticles

“…As another purification process, gel filtration can be used (210). It is also much faster than methods based on simple dialysis but it is greatly limited by the relatively small volume of sample which can be processed at a time.…”

Methods for purifying and detoxifying sodium dodecyl sulfate–stabilized polyacrylate nanoparticles

“…Indeed, it has been observed before that the toxicity of surfactants, including SDS in particular, depends on whether they are unassociated (in bulk media) or bound to the surface of nanoparticles. [14] A variety of methods to purify nanoparticles have been reported in the literature, including centrifugation, [23] ultracentrifugation, [24] gel filtration, [12] ultrafiltration, [25] dialysis, [26] diafiltration centrifugal device and tangential flow filtration. [27] The various applications and sample compositions make it difficult to predetermine an effective, standardized and practical purification method for the polyacrylate system.…”

“…Furthermore, purification procedures were required before we could initiate more detailed structural characterization of the emulsified nanoparticles or investigate their application as treatments in animal infection models. [12] In this report, we describe purification methods for this purpose, and the effect the purification procedure has on the overall microbiological and cytotoxic properties of the resulting nanoparticle emulsion. In particular, we pay close attention to the role that the surfactant, SDS, may have on the antibacterial and cellular toxicity of the nanoparticle emulsions.…”

Comparison of Diafiltration and Tangential Flow Filtration for Purification of Nanoparticle Suspensions

“…Centrifugation or ultracentrifugation techniques are commonly used for removal of organic solvents, free drug, or free stabilizer such as polyvinyl alcohol (PVA) and electrolytes (6,8Y10). Dialysis techniques (11), gel filtration (12), ultrafiltration (13), and, more recently, diafiltration (14,15) and cross-flow microfiltration (5,16) have been investigated for the purification of nanoparticles. Centrifugation or ultracentrifugation, in combination with washing nanoparticles with an appropriate medium such as deionized water, is the most common approach to remove large quantities of process impurities (17,18).…”