Polymer-plasticizer compatibility during coating formulation: A multi-scale investigation

Abstract

During the formulation of solid dosage forms coating, plasticizers are added to the film forming polymer to improve the mechanical properties of the coating shell of the drug product. For the coating formulation to be successful and in order to produce flexible continuous film, the plasticizer should be compatible with the film forming polymer (i.e. high plasticizer-polymer miscibility in solid dispersion) (McGinity and Felton, 2008). This paper proposes and compares different multi-scale methods to predict the compatibility between plasticizers and film formers. The methods are based on, i) Molecule charge density using COSMO, ii) Solubility parameter calculation using Molecular dynamics, iii) Mesoscale simulation using DPD, where we propose a coarse-grain model, and iv) experimental DSC analysis for validation. The methods are tested for various blends including HPMC-PEG, MCC-PEG and PVP-PEG. The different methods showed similar results; PEG plasticizer diffuses inside HPMC and PVP polymer chains, thereby extending and softening the composite polymer. However, MCC surrounds PEG molecules without diffusing in its network, indicating low PEG-MCC compatibility. We also found that DPD simulations offer more details than the other methods on the miscibility between the compounds in aqueous solid dispersion, and can predict the amount of plasticizer that diffuse in the film forming polymer network.

A Strategy for Nonmigrating Plasticized PVC Modified with Mannich base of Waste Cooking Oil Methyl Ester

“…However, the phthalate esters are easy to migrate from polymer matrix during processing and using with increasing time, which decreases the service life of polymer products, as well as potential toxicity to human body 11 , 12 . Recently, epoxidized vegetable oil 13 , 14 , polymer plasticizer 13 , 15 , polyol ester 16 , 17 and phosphate plasticizer 14 have been reported as alternative plasticizers, which suppresses the migration from PVC products in a certain degree, but epoxidized vegetable oil, polyol ester and phosphate plasticizer will migrate from PVC products with increasing time. The effective strategy to avoid the migration of plasticizers is covalent attachment of the plasticizer onto the PVC backbone 18 – 20 .…”

Experimental and Simulation Study on Glass Transition Temperatures of GAP with Ionic‐Liquid‐Based Energetic Plasticizers

“…Changes in the anion of the ionic liquid can affect the Tg of the GAP/ionic liquid plasticizer. These changes could result in the variation of ion movement and anion‐cation Van der Waals force .…”

Post Modification of Poly Glycidyl Azide with Ionic‐Liquid‐Based Reactive Plasticizer through Catalyst‐Free Click Reaction

“…In our studies on the effect of the ionic liquid type on the Tg of the GAP, we found that the anion changes of the ionic liquid plasticizer from bromide to dicyanamide led to the reduction of Tg up to 9 °C. The reason for this reduction could be the change in the ion movement and anion‐cation Van der Waals force, because increasing the ions size enhanced the Van der Waals force ,…”

“…However, the most important drawback in the application of GAP is its rather low flexibility in a pure state. For more durability and flexibility, plasticizers are often used together with this material . Plasticizers are normally small molecules inserted between the polymeric chains to improve the flexibility and processability features of the propellant mixture.…”