Table 2.
Additional information regarding the type of polymers most commonly employed in 3D printing medicines.
| Polymer | FDA Approval | Bio-Degradable Polymer | Characteristics | Technique Commonly Employed | Reference |
|---|---|---|---|---|---|
| Tween 20 (Polysorbate 20) | ✓ | ✓ | GRAS status—Good surfactant properties | CIJ | [10,11,14,15] |
| Eudragit E100 (Cationic methacrylic ester copolymer) | ✓ | ✓ | Soluble under acidic conditions (<pH 5) | Powder Bed Fusion | [4,15,16] |
| Eudragit RLPO (Copolymer of methacrylic ammonium acid) | ✓ | ✓ | Insoluble in permeable water regardless of pH | Powder Bed Fusion | [4,15,16] |
| MCC (Microcrystalline cellulose) | ✓ | ✓ | Used as a disintegrator | FDM | [15,17] |
| Polyacrylic acid (PAA) | ✓ | ✓ | Used as a hydrophilic matrix | FDM | [15,17] |
| Polyvinyl alcohol (PVA) | ✓ | ✓ | Biocompatible water-soluble synthetic polymer capable of swelling upon contact with aqueous fluids. | FDM | [4,12,15,17] |
| Polyacid-L-lactic (PLLA) | ✓ | ✓ | Biodegradable aliphatic polyester that comes from renewable resources such as corn starch, tapioca roots or sugar cane | FDM | [12,15,17,18] |
| Polyetherimide (PEI) | X | X | Remains unchanged after autoclaving | FDM | [17,19] |
| Polyphenylsulfone (PPSF) | X | X | Known as RADEL. High heat and chemical resistance. |
FDM | [15,19] |
| Policaprolactone (PCL) | ✓ | ✓ | Biocompatible polyester, used in wound dressings, tissue engineering and drug administration | FDM | [15,18,20] |
| NinjaFlex® (NF) | ✓ | ✓ | Thermoplastic polyurethane widely used for regeneration, bone substitution and drug delivery | FDM | [15,20] |
| PLA flexible variety (FPLA) | ✓ | ✓ | Aliphatic polyester with adequate mechanical strength and low toxicity | FDM | [15,18,20] |
| Methocel® E5 (matrix gel) | ✓ | ✓ | Used for immediate release tablets | PAM | [4,15] |
| Hydroxypropyl Methylcellulose (HPMC) | ✓ | ✓ | Used for drug released tablets and polypills | PAM | [4,15,17] |
| Carbopol® 974P (Polymer crosslinked acrylic acid) | ✓ | ✓ | Used for sustained release purposes | PAM | [15,17] |
| Polyethylene glycol diacrylate (PEGDA) | X | ✓ | Used as liquid photopolymer | SLA | [4,15,18,20] |
| Polyethylene glycol (PEG) | ✓ | ✓ | Solidifies with the action of a laser beam | SLA | [15,17,20] |