Lyophilization of Nanocapsules: Instability Sources, Formulation and Process Parameters

Abstract

Polymeric nanocapsules have gained more and more interest in the medical sciences. Their core-shell structure offers numerous advantages, especially regarding their use as drug delivery systems. This review begins by presenting the different intrinsic sources of the instability of nanocapsules. The physical and chemical potential instabilities of nanocapsules reduce their shelf-life and constitute a barrier to their clinical use and to their commercialization. To overcome these issues, lyophilization is often used as a process of choice in the pharmaceutical industry especially when labile compounds are used. The state of the art of lyophilization nanocapsules is reviewed. The formulation properties and the process parameters are discussed for a complete understanding of their impact on the stability and storage of the final dried product. To assess the quality of the dried product, various characterization methods are also discussed.

Craft of Co-encapsulation in Nanomedicine: A Struggle To Achieve Synergy through Reciprocity

“…Such intra- or intermolecular interactions and rearrangements may cause an ionic imbalance inside the nanocarrier, affecting colloidal stability. Lyophilization of the formulations into powder form can be a way to address the issue of compromised stability, although it comes with the caveat of reconstituting into an injectable form, which remains a challenge in the absence of surfactants . The surfactants categorized as Generally Regarded As Safe (GRAS) entities provide a limited choice for pharmacists.…”

Stability Phenomena Associated with the Development of Polymer-Based Nanopesticides

“…The solid-state presentation could require a lyophilization process in most examples of polymer-based nanopesticides. Lyophilization consists of a sublimation process to remove water under reduced pressure with a supply of energy in low-temperature ranges, facilitating the product's drying without altering the product's structural integrity [ 93 ]. The lyophilization processes of polymer-based nanopesticides can produce the coalescence of the polymeric nanoparticles irreversible changes in size and shape of the nanocarriers, for which the presence of cryoprotective agents is necessary [ 93 ].…”

“…Lyophilization consists of a sublimation process to remove water under reduced pressure with a supply of energy in low-temperature ranges, facilitating the product's drying without altering the product's structural integrity [ 93 ]. The lyophilization processes of polymer-based nanopesticides can produce the coalescence of the polymeric nanoparticles irreversible changes in size and shape of the nanocarriers, for which the presence of cryoprotective agents is necessary [ 93 ]. Traditionally, the addition of cryoprotective sugars such as trehalose, maltose, sucrose, and mannitol has adequate performance in a concentration range of 2 to 5% in preserving the physical properties of the nanoparticles [ 94 ].…”

Revisión del estado actual de las formulaciones y aplicaciones de astaxantina producida por Haematococcus pluvialis

“…Como la astaxantina es una molécula muy inestable, se requiere de un proceso de encapsulación que tenga la capacidad de formar una matriz polimérica o un material de pared que proteja su actividad biológica de los factores ambientales (Pan-utai et al, 2021). Por ejemplo, el secado por aspersión permite eliminar los disolventes como el agua para que la sustancia de forma seca conserve sus propiedades principales (Degobert & Aydin, 2021), el liofilizado busca deshidratar la biomasa de las microalgas y preservar su pared celular (Pan-utai et al, 2021), y las emulsiones convencionales o nanoemulsiones de aceite en agua (O/W) constan de dos líquidos inmiscibles, en los que una fase oleosa se dispersa como gotitas en una fase acuosa para mejorar la estabilidad fisicoquímica de la molécula (Khalid et al, 2017).…”