Statistical design of experiment-based formulation development and optimization of 3D printed oral controlled release drug delivery with multi target product profile

Natural Alternatives to Non-biodegradable Polymers in 3D Printing of Pharmaceuticals

BACKGROUND

Due to potential toxicity, non-biodegradable polymers used in 3D (3-dimensional) printing of drugs could be dangerous for patient safety and the environment.

OBJECTIVE

This review aims to investigate the toxicity of non-biodegradable polymers and investigate the use of natural materials as an alternative in 3D printing medicines. The study evaluates the dangers connected to 3D printing.

METHODS

A review of the literature on various 3D printing processes, such as inkjet printing, fused filament manufacturing, and extrusion-related 3DP systems, was done for this study. Also, the use of cellulose derivatives and natural materials in 3D printing and their potential as active excipients was proposed.

RESULTS

The review identified potential toxicity risks linked to non-biodegradable polymers used in drug 3D printing. As a potential fix for this issue, the use of natural materials with improved mechanical and thermal properties was explored. The use of cellulose derivatives as an alternative to non-biodegradable polymers in 3D printing pharmaceuticals was also investigated in the study.

CONCLUSION

This study emphasises the significance of evaluating the risks connected to drug 3D printing and recommends using natural materials as an alternative to non-biodegradable polymers. More study is required to create secure and reliable 3D printing processes for pharmaceuticals.

Rheological Investigation of Hydroxypropyl Cellulose–Based Filaments for Material Extrusion 3D Printing

The rheological properties of drug–polymer mixtures have a significant influence on their processability when using transformative techniques, such as hot-melt-extrusion and material-extrusion 3D printing; however, there has been limited data on printable systems. This study investigated the rheological properties of 17 formulations of successful printed tablets for both immediate and controlled release. Hydroxypropyl cellulose was used in various ratios to obtain printable filaments in combination with various drugs (indomethacin or theophylline), polymers and disintegrants. The complex viscosity, shear thinning behavior and viscoelastic properties were affected by the drug load, polymer composite, disintegrant type, temperature and shear rate applied. Larger windows of processing viscosity were revealed. The viscosity of the printable blends could be as low as the range 10–1000 Pa·s at 100 rad/s angular frequency. All formulations showed shear thinning behavior with a broad slope of complex viscosity from −0.28 to −0.74. The addition of 30–60% drug or disintegrant tended to have greater viscosity values. While microcrystalline cellulose was found to be an alternative additive to lower the storage and loss modulus among disintegrants. This rheological data could be useful for the preformulation and further development of material-extrusion 3D-printing medicines.

Fused Deposition Modeling as a Possible Approach for the Preparation of Orodispersible Tablets

Additive manufacturing technologies are considered as a potential way to support individualized pharmacotherapy due to the possibility of the production of small batches of customized tablets characterized by complex structures. We designed five different shapes and analyzed the effect of the surface/mass ratio, the influence of excipients, and storage conditions on the disintegration time of tablets printed using the fused deposition modeling method. As model pharmaceutical active ingredients (APIs), we used paracetamol and domperidone, characterized by different thermal properties, classified into the various Biopharmaceutical Classification System groups. We found that the high surface/mass ratio of the designed tablet shapes together with the addition of mannitol and controlled humidity storage conditions turned out to be crucial for fast tablet’s disintegration. As a result, mean disintegration time was reduced from 5 min 46 s to 2 min 22 s, and from 11 min 43 s to 2 min 25 s for paracetamol- and domperidone-loaded tablets, respectively, fulfilling the European Pharmacopeia requirement for orodispersible tablets (ODTs). The tablet’s immediate release characteristics were confirmed during the dissolution study: over 80% of APIs were released from printlets within 15 min. Thus, this study proved the possibility of using fused deposition modeling for the preparation of ODTs.

Pharmaceutical Applications of Supercritical Fluid Extraction of Emulsions for Micro-/Nanoparticle Formation

Micro-/nanoparticle formulations containing drugs with or without various biocompatible excipients are widely used in the pharmaceutical field to improve the physicochemical and clinical properties of the final drug product. Among the various micro-/nanoparticle production technologies, emulsion-based particle formation is the most widely used because of its unique advantages such as uniform generation of spherical small particles and higher encapsulation efficiency (EE). For this emulsion-based micro-/nanoparticle technology, one of the most important factors is the extraction efficiency associated with the fast removal of the organic solvent. In consideration of this, a technology called supercritical fluid extraction of emulsions (SFEE) that uses the unique mass transfer mechanism and solvent power of a supercritical fluid (SCF) has been proposed to overcome the shortcomings of several conventional technologies such as solvent evaporation, extraction, and spray drying. This review article presents the main aspects of SFEE technology for the preparation of micro-/nanoparticles by focusing on its pharmaceutical applications, which have been organized and classified according to several types of drug delivery systems and active pharmaceutical ingredients. It was definitely confirmed that SFEE can be applied in a variety of drugs from water-soluble to poorly water-soluble. In addition, it has advantages such as low organic solvent residual, high EE, desirable release control, better particle size control, and agglomeration prevention through efficient and fast solvent removal compared to conventional micro-/nanoparticle technologies. Therefore, this review will be a good resource for determining the applicability of SFEE to obtain better pharmaceutical quality when researchers in related fields want to select a suitable manufacturing process for preparing desired micro-/nanoparticle drug delivery systems containing their active material.