Crystallographic Textures and Morphologies of Solution Cast Ibuprofen Composite Films at Solid Surfaces

Abstract

The preparation of thin composite layers has promising advantages in a variety of applications like transdermal, buccal, or sublingual patches. Within this model study the impact of the matrix material on the film forming properties of ibuprofen–matrix composite films is investigated. As matrix materials polystyrene, methyl cellulose, or hydroxyl-ethyl cellulose were used. The film properties were either varied by the preparation route, i.e., spin coating or drop casting, or via changes in the relative ratio of the ibuprofen and the matrix material. The resulting films were investigated via X-ray diffraction and atomic force microscope experiments. The results show that preferred (100) textures can be induced via spin coating with respect to the glass surface, while the drop casting results in a powder-like behavior. The morphologies of the films are strongly impacted by the ibuprofen amount rather than the preparation method. A comparison of the various matrix materials in terms of their impact on the dissolution properties show a two times faster zero order release from methyl cellulose matrix compared to a polystyrene matrix. The slowest rate was observed within the hydroxyl ethyl cellulose as the active pharmaceutical ingredients (APIs) release is limited by diffusion through a swollen matrix. The investigation reveals that the ibuprofen crystallization and film formation is only little effected by the selected matrix material than that compared to the dissolution. A similar experimental approach using other matrix materials may therefore allow to find an optimized composite layer useful for a defined application.

Surface Induced Phenytoin Polymorph. 1. Full Structure Solution by Combining Grazing Incidence X-ray Diffraction and Crystal Structure Prediction

“…In addition to conventional bulk (solution) crystal form screening experiments, crystallization becomes more frequently investigated under more restricted environments like pores, 4 matrices, 5 or just at solid surfaces. 6 In any of those cases, the surface contact influences the nucleation.…”

Controlling Indomethacin Release through Vapor-Phase Deposited Hydrogel Films by Adjusting the Cross-linker Density

“…The drug release from such polymer systems is usually facilitated by either degradation/erosion of the polymer host or by diffusion of the drug; for the latter mechanism, matrix-, reservoir- and hydrogel-based systems are usually differentiated 8 . In matrix systems, the API is homogenously dispersed inside a suitable host material such as cellulose 9 or lipids 10 , with the tortuosity of the material determining release kinetics 11 . While hydrogel systems can also be considered matrix systems as they are usually loaded with an API, drug release occurs upon swelling of the hydrogel and is governed by the mesh size of the polymer 12 .…”

Polymer Encapsulation of an Amorphous Pharmaceutical by initiated Chemical Vapor Deposition for Enhanced Stability

“… 14 For racemic ibuprofen on glass surfaces, crystallization requires more than 2 weeks, while cellulose surfaces lead to crystallite formation already within a day. 15 As new formulation strategies are under development, personalized medicine might benefit from such amorphous states because the shelf life might not be the limiting parameter for successful application. Surfaces are not only capable of stabilizing amorphous states but have also the potential to facilitate crystallization into specific polymorphs or with distinct crystallographic orientations (texture).…”