Page 523 - IJB-9-6

International Journal of Bioprinting Advances for 3D-printed oral drug delivery systems

methods are needed to characterize the 3D-printed dosage use of colorimetric evaluations for direct and indirect
forms without total loss of all the samples. determination of extruded filaments with API and/or
coloring agents . The results showed that colorimetry can
[92]
To ensure final product quality of paracetamol printlets, be used as a quality control tool to detect differences in
non-destructive characterization techniques like process drug loading .
[92]
analytical technologies, near-infrared spectroscopy (NIR),
and Raman confocal microscopy can be applied. Trenfield 3.3.3. Protocol and standardization
et al. evaluated cylindrical 3D-printed tablets . A Standards and protocols are guidelines for production
[88]
calibration model was created using an NIR spectrometer, that ensure consistent quality and safety. In this sub-
and it successfully predicted the drug concentration. section, protocols developed for 3D-printed dosage forms
The model also demonstrated excellent linearity and are presented.
accuracy with dosage forms of different geometries and Silva et al. proposed a new protocol for preformulation
formulations. The drug distribution was observed with a studies simulating thermal processing and aging of
Raman confocal microscopy .
[88]
the fused deposition modeling printed medicines. The
Trenfield et al. verified the dosage of multiple drugs protocol included tests related to morphology and thermal,
in polyprintlets and 3D-printed films at the point of crystallographic, and spectroscopic profiles. In the study,
dispensing . The dosage forms were loaded with the protocol simulated the combined thermal stresses of
[89]
amlodipine and lisinopril. The analysis and verification formulations with four different polymers and two model
[93]
were made using a portable NIR spectrometer and drugs and obtained stable pharmaceutical dosage forms .
validated calibration models (partial least squares Pressure-assisted microsyringe (PAM) was selected by
regression). The results demonstrated an excellent linearity, Callede et al. to develop zolpidem printlets . The design
[94]
accuracy, and specificity for amlodipine and lisinopril. The process included the integration of protocols to standardize
microstructure was observed with x-ray powder diffraction compounding procedures (mixing, preparation, and
(XRPD) and thermogravimetric analysis (TGA) . printing) related to the dosage amount of zolpidem in
[89]
Gioumouxouzis et al. investigated the structural the tablets. The printing parameters were evaluated and
and functional characterization of 3D-printed dosage optimized, and some of them were fixed at certain values.
forms with x-ray microfocus computed tomography One of the outcomes of the research was a decision tree
(μCT) to verify if the formulations complied with the model that allows the compounding pharmacists to ensure
required specifications (quality assurance) . The quality control of the zolpidem printlets at industry level
[90]
[94]
results demonstrated that the use of μCT can perform a immediately after printing .
qualitative inspection of the products, a 3D image of the 3.3.4. Factors of influence
dosage form structure for dimensional metrology, and High-quality products can be obtained by optimizing
the functional performance of the formulation overtime. process or formulation parameters. This sub-section
The authors believe that μCT can help accelerate the contains publications related to the effects of a factor of
adoption of 3D printing technology in the pharmaceutical influence (selected by the author of each article) on the
technology sector . properties of the 3D-printed oral DDS.
[90]
Lima et al. employed oscillatory shear rheology Zhang et al. studied the influence of process
and mechanical evaluation as a control tool for fused temperature on the quality and crystallinity of fused
deposition modeling 3D-printed medicines. Hot melt deposition modeling-printed phenytoin dosage forms .
[95]
extrusion filaments were assessed in terms of viscoelastic Comparative studies such as morphology, solid-state
behavior, definition of printing parameters, and the analysis, and in vitro drug release between the printlets
prediction of their repercussions on the 3D tablets. The and filaments were carried out. The results showed that the
outcome of this research was the validation of oscillatory printing process and product qualities are affected by the
shear rheology as a tool to identify significantly sensitive printing temperature and slicing .
[95]
viscoelastic alterations and quality control parameters, and
as a method to predict rheological changes and their effects The quality of binder jetting paracetamol
on the printed dosage forms . orodispersible films was improved by adding a thin layer
[91]
of polyvinylpyrrolidone (PVP) coating to the matrix
Quality control of 3D-printed dosage forms particles. Wang et al. concluded that coated particles
can also be done on hot melt extrusion API-loaded improved the resistance to crushing and decreased the
filaments. Chamberlain et al. investigated the possible disintegration time .
[96]

Volume 9 Issue 6 (2023) 515 https://doi.org/10.36922/ijb.1119