Kollidon® SR: Formulation techniques and drug delivery applications

Abstract

Kollidon® SR is one of the recent versatile coprocessed excipients in the formulation of modified release dosage forms. It is prepared by co-spray drying from aqueous dispersions of polyvinylacetate and polyvinylpyrrolidone. This article gives a critical review of the physicochemical attributes and technological properties of Kollidon® SR. The current review discusses various technological approaches used in the formulation with Kollidon® SR, from conventional ones like direct compaction and wet granulation to more advanced methodologies such as 3D printing, electrospinning and hot-melt extrusion. The review further elaborates on the influence of the major factors on drug release kinetics from Kollidon® SR-based formulations. Furthermore, this review unravels the potential of Kollidon® SR in the development of site-targeted oral drug delivery systems and focuses on its adaptability to other routes of administration. Further, the review deals with the considerations to be made regarding stability to make sure the formulations based on Kollidon® SR are reliable.

Highlights

Kollidon® SR is a co-processed excipient for modified-release dosage forms.

Kollidon® SR has been formulated into various dosage forms using various processing techniques.

The drug release rate from Kollidon® SR-based matrix systems is influenced by formulation and processing methods.

Post-processing thermal curing enhances the physical stability of Kollidon® SR-based matrices.

Introduction

Kollidon® SR is a co-spray-dried powder composed of 80 % PVAc, 19 % povidone (PVP) K30, around 0.8 % sodium lauryl sulfate and 0.2 % silica and has been commercialized since 1999 (Shao et al., 2001). It is prepared by co-spray drying aqueous colloidal dispersions of PVAc, PVP, sodium lauryl sulfate and silica. Kollidon® SR offers a combination of excellent flow, compression and compaction properties (Hauschild and Picker-Freyer, 2006), which has made it specially suitable and robust as a matrix former for sustaining drug release by direct compression. The drug release from Kollidon® SR-based formulations has been reported to be highly independent of the compression force (BASF, 2014, Kranz and Wagner, 2006, Siepmann et al., 2010) and pH of the dissolution medium (Draganoiu, 2003, Mulani et al., 2011, Siepmann et al., 2010), potentially making it more versatile in variable gastrointestinal environments. Notably, the major component (PVAc) is very plastic (Bühler, 2008, Kolter et al., 2013, Lin et al., 2020, Nguyen et al., 2020) imparting Kollidon® SR with a distinctive character of retaining tablets geometric shape during dissolution test even for those prepared using low compression forces, a property that could be advantageous for ensuring reproducible drug release. Additionally, PVP is a strong binder that contributes to the mechanical strength of tablets. Moreover, as PVP is water-soluble, it gradually leaches out of the matrix during dissolution, thereby creating pores for the active ingredient to diffuse out (Draganoiu et al., 2001).

While initially presented as a directly-compressible matrix former for tablet dosage forms, Kollidon SR’s versatility has been extensively explored in various processes and diverse dosage forms across multiple administration routes. This review seeks to examine the versatility and limitations of Kollidon® SR in drug delivery based on up-to-date published research.