Techniques of Mucilage and Gum Modification and their Effect on Hydrophilicity and Drug Release

Aim: The manuscript aims to describe the techniques of modification of gums and mucilages and their effect on hydrophilicity and drug release. Discussion: The interest is increased in the fields of polymers which is obtained from natural origin and used in the preparation of pharmaceuticals. Mucilage and gum are natural materials, widely used in the preparation of novel dosage form and conventional dosage form. They are used in the pharmaceutical industry for various purposes like suspending, emulsifying, bio-adhesive, binding, matrix-forming, extended release and controlled release agent. Gum and mucilage are biodegradable, less toxic, cheap and easily available. Moreover, mucilage and gum can be changed to acquire tailored materials for the delivery of drugs and allow them to compete with commercially available synthetic products. These polysaccharides have unique swellability in an aqueous medium that can exert a retardant effect on drug release or act as a super disintegrant, depending on the concentration utilized in the preparation. Drug release mechanism from hydrophilic matrices consisting of gums and mucilages is based on solvent penetration-induced polymer relaxation, diffusion of entrapped drug followed by degradation or erosion of the matrix. Conclusion: The present manuscript highlight the advantages, modifications of gum and mucilage, their effects on hydrophilicity and drug release as well as aspects of the natural gums which can be assumed to be bifunctional excipient because of their concentration-dependent effect on drug release and their high degree of swellability.

Plasticiser-Free 3D Printed Hydrophilic Matrices: Quantitative 3D Surface Texture, Mechanical, Swelling, Erosion, Drug Release and Pharmacokinetic Studies

Hydroxypropyl methyl cellulose, HPMC, a hydrophilic polymer, is widely used for the development of extended release hydrophilic matrices and it is also considered as a good contender for the fabrication of 3D printing of matrix tablets. It is often combined with plasticisers to enable extrusion. The aim of the current project was to develop plasticizer-free 3D printed hydrophilic matrices using drug loaded filaments prepared via HME to achieve an in vitro (swelling, erosion and drug release) and in vivo (drug absorption) performance which is analogous to hydrophilic matrix tablets developed through conventional approaches. Additionally, the morphology of the printed tablets was studied using quantitative 3D surface texture studies and the porosity calculated. Filaments were produced successfully and used to produce matrix tablets with acceptable drug loading (95–105%), mechanical and surface texture properties regardless of the employed HPMC grade. The viscosity of HPMC had a discernible impact on the swelling, erosion, HPMC dissolution, drug release and pharmacokinetic findings. The highest viscosity grade (K100M) results in higher degree of swelling, decreased HPMC dissolution, low matrix erosion, decreased drug release and extended drug absorption profile. Overall, this study demonstrated that the drug loaded (glipizide) filaments and matrix tablets of medium to high viscosity grades of HPMC, without the aid of plasticisers, can be successfully prepared. Furthermore, the in vitro and in vivo studies have revealed the successful fabrication of extended release matrices.