INTRODUCTION:

Orodispersible strip, usually refer as orodispersible film, nowadays have emerged as a patient-centric dosage form, particularly suited for paediatric, geriatric, and dysphagic populations due to thin, mechanically strong, and flexible polymeric films that are designed to dissolve or disintegrate rapidly in the oral cavity for local and/or systemic drug delivery. In the pharmaceutical field, hydrocolloids play a crucial role in forming Orodispersible Strip (ODS) - a modern oral dosage form designed for rapid disintegration upon contact with saliva, eliminating the need for water or swallowing.

ODS are especially beneficial for pediatric, geriatric, and dysphagic patients who often experience difficulty swallowing traditional tablets or capsules. Approximately 35% of the global population suffers from dysphagia, making ODS an ideal patient-centric solution¹. The European Pharmacopoeia identifies orodispersible strip as solid dosage forms dissolving in 3 minutes on placement in the mouth². When dissolved, the drug gets absorbed through the mucosal lining or is swallowed, resulting in high speed of action and increased bioavailability especially in the drugs that are susceptible to first-pass metabolism³. Three-dimensional (3D) printing is a new technology that has recently become a revolution in the pharmaceutical manufacturing process. As defined by the International Standard Organization (ISO), 3D printing involves the production of objects by laying material down with a print head, nozzle or other technology of printing dosage forms⁴. Exceptional control over drug dosage, geometry and release characteristics is possible with this technology, and advance personalized medicine whereby therapies can be customized to the needs of individual patients⁵.

The current review focuses in detail on the exploration of the existing innovations and new trends of ODS ready to be used with hydrocolloids in terms of design, formulation ingredients, and production methods to be used in potential oral BCS IIdrugs delivery, and the introduction of new technology into it, such as 3D printing.

1. Hydrocolloids:

Hydrocolloids are a massive and eclectic category of polymeric substances, which are mainly made out of polysaccharides and some proteins. These macromolecules have the capacity of dispersing or dissolving in water, creating a colloidal dispensing that greatly alters the physical properties of aqueous solutions by means of gel formation, thickening, emulsifying, coating, and stabilizing⁶. They may be obtained as a variety of naturally occurring materials such as plants, animals, algae, and microorganisms or as a variety of synthesized or semi-synthetic derivatives such as cellulose ethers. These are commonly starch, agar, carrageenan, gelatin, pectin, xanthan gum and guar gum.

Hydrocolloids are hydrophilic; they take in water and swell to create gels or viscous solutions based on the concentration and the environmental condition. Gelatin is a protein hydrocolloid especially distinguished by hydrophilicity and multi-dispersion capabilities which allow it to be extensively used as a gelling, stabilizing, coating agent in food and pharmaceutical industries⁷. Hydrocolloids are important excipients in the creation of innovative drug delivery systems due to their capability to control viscosity, alter texture, and improve stability.

Working with hydrocolloids, hydroxypropyl methylcellulose (HPMC), gelatin, sodium carboxymethyl cellulose (NaCMC), hydroxypropyl cellulose (HPC), pectin, and pullulan are the most common polymers employed in ODS formulations because of their high biocompatibility with excellent mechanical strength and hydrophilic behavior⁸. These substances permit the development of flexible, homogeneous and dissolved strips in a short period of time that can accommodate various Active Pharmaceutical Ingredients (APIs), including those with low dissolvability in water.

1.1. Natural Hydrocolloids:

The use of natural polymers in ODS formulations is because of their biodegradability, biocompatibility and non-toxicity. Examples of these are pullulan, gelatin, pectin, xanthan gum, guar gum, carrageenan and gum arabic.

One of the most versatile natural film formers applied in ODS is pullulan which is a linear polysaccharide synthesized by Aureobasidium pullulans. It manufactures transparent, elastic and smooth Strip having high oxygen blockage qualities. Strip made of pullulan dissolve quickly when in contact with the saliva and can therefore be used in immediate-release systems. Kukec et. al.⁹ are the ones who described the preparation of fast-dissolving pullulan strip with griseofulvin nanoparticles (a BCS IIdrug), which showed greater than 80 percent drug release in 30 minutes because of improved wetting and more surface area of dispersed nanoparticles.

Gelatin is clear and elastic Strip that has a good mouthfeel, but is thermally unstable and sensitive to moisture. Gelatin can be combined with hydrophilic polysaccharides like starch, pectin or sodium carboxymethyl cellulose (NaCMC) to combat these drawbacks to enhance its mechanical strength and disintegration behavior¹⁰.

On the same note, sodium alginate, a brown seaweed polysaccharide, which is an anionic polysaccharide, is used to give flexible Strip a great mucoadhesive and film-forming properties. In ODS formulations, plasticizers (e.g., glycerol, polyethylene glycol 400) are normally added to increase flexibility and decrease brittle nature¹¹.

Xanthan gum and guar gum act as viscosity enhancers and stabilizers in the film-forming solution. They prevent sedimentation of poorly soluble drugs during casting and promote uniform film thickness. Moreover, their hydrophilic nature aids in rapid film hydration and disintegration when placed in the oral cavity¹². However, the Strip formed solely from natural gums often display inferior mechanical strength; therefore, they are generally used in combination with semi-synthetic cellulose derivatives¹³.

1.2. Semi-Synthetic Hydrocolloids (Cellulose Derivatives):

Cellulose-based polymers are the most widely used film-forming agents in ODS due to their film uniformity, controlled viscosity, and safety profile. Among them, hydroxypropyl methylcellulose (HPMC) is the most commonly employed due to its excellent balance between mechanical strength, transparency, and rapid disintegration. HPMC is available in various viscosity grades (E3, E5, E15, etc.), which influence the rheological behaviour of the casting solution and the resulting film thickness¹⁴.

Strip based on HPMC have been used for BCS II drugs such as granisetron, meloxicam, and donepezil, showing enhanced drug dissolution and uniformity of content. HPMC’s hydrophilic and amorphous nature allows it to molecularly disperse poorly soluble drugs, preventing recrystallization during storage and thereby improving bioavailability.

Hydroxypropyl cellulose (HPC) is another semi-synthetic cellulose derivative with higher hydrophobic substitution. It offers better versatility but reduced speed of hydration than HPMC. HPC when combined with HPMC controls the disintegration rate as well as the mechanical properties of the film. In a research by Musazzi et al., orodispersible Strip that contained Loperamide hydrochloride were made in different ratios of HPMC:HPC. It was found that polymer composition affected the solid state of the drug as well as the dissolution characteristics, which indicates the significance of the polymer-drug interactions in film systems¹⁵.

Co-formers are the cellulose derivatives and commonly used as co-formers, to enhance viscosity, flexibility and mouthfeel: sodium carboxymethyl cellulose (NaCMC), ethyl cellulose (EC) and methyl cellulose (MC). They are hydrophilic and help in the penetration of water, which leads to disintegration of the film in the mouth cavity very fast¹⁶.

1.3. Synthetic Film-Forming Polymers:

Other common synthetic polymers used ODS formulations include polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) which are reproducible and have the ability to perform better in terms of mechanical properties¹⁷. PVA is the creative of strong, stretchy, and transparent Strip that cannot be torn. Due to its slow hydration rate, though, PVA is commonly used together with fast-dispersing polymers such as HPMC or pullulan in order to be disintegrated optimally¹⁸. PVP is a highly hydrophilic polymer, which serves as an agent of forming a film and solubilizer. It improves the solubility of drugs that cannot be dissolved. by hydrogen bonding and dispersion formation by amorphous solid¹⁹.

Combinations of PVA, PVP, and HPMC have been shown to produce mechanically robust Strip with rapid disintegration, making them particularly suitable for BCS II APIs such as itraconazole, ketoprofen, and carvedilol¹⁹. Additionally, synthetic polymers are advantageous for scalable production processes such as solvent casting, hot-melt extrusion, and emerging 3D printing techniques²⁰.

1.4. Modified Starches and Other Polysaccharides:

Modified starches, maltodextrins, and pre-gelatinized starches are cost-effective hydrocolloids frequently used in combination with cellulose derivatives to improve film flexibility and disintegration behavior. These materials exhibit high solubility and excellent mouthfeel, which enhances patient compliance²¹.

Tiryaki et al., developed desloratadine ODS using pre-gelatinized starch and HPMC, producing Strip that disintegrated within 30 seconds while maintaining good tensile strength and homogeneity²². Maltodextrins, due to their low molecular weight and rapid solubility, further aid in the taste masking of bitter drugs and in achieving a pleasant oral sensation²³.

1.5. Polymer Blends and Composite Systems:

Since no single polymer meets all the functional requirements of orodispersible Strip - such as high flexibility, fast disintegration, and sufficient mechanical strength - polymer blending has become an established formulation strategy²⁴. Some of hydrocolloids and its functions are summarized in Table 1.

HPMC–HPC blends have demonstrated superior balance between strength and disintegration time¹⁵, with higher HPC ratios generally reducing disintegration time. Similarly, pullulan - xanthan and HPMC - PVA blends have shown synergistic improvements in flexibility, film uniformity, and drug dispersion¹³. Polymer blends also minimize film brittleness, prevent phase separation, and stabilize amorphous drug forms - critical factors for BCS II drugs that are prone to recrystallization²⁵.

Table 1: Hydrocolloids and its functions

Polymer Type	Example Polymer(s)	Origin/Chemical Nature	Functional Role in ODS	Advantages	Limitations / Remarks
Natural Hydrocolloids	Pullulan²¹	Polysaccharide produced by Aureobasidium pullulans	Primary film former; provides transparency and elasticity	Rapid dissolution, pleasant mouthfeel, good oxygen barrier	Moisture sensitive, costly
	Gelatin²⁶	Protein derived from collagen	Film formation, mechanical strength	Clear, flexible, biocompatible	Thermal instability, moisture sensitivity
	Sodium Alginate¹¹	Anionic polysaccharide from brown algae	Film former, mucoadhesive agent	Excellent film strength, non-toxic	Brittle without plasticizer
	Pectin¹²	Galacturonic acid polysaccharide	Disintegrant, co-former	Biodegradable, smooth texture	Brittle in dry state
	Xanthan Gum/ Guar Gum¹²	Natural polysaccharides	Viscosity enhancer, stabilizer	Improves film uniformity	Poor mechanical strength alone
Semi-Synthetic Hydrocolloids (Cellulose Derivatives)	HPMC (E3, E5, E15²⁷	Etherified cellulose	Main film former	Uniform, transparent, rapid disintegration, stabilizes amorphous drugs	Costly, moderate tensile strength
	HPC¹⁸	Partially etherified cellulose	Co-former, flexibility enhancer	Flexible, smooth Strip	Slower hydration vs HPMC
	NaCMC¹⁸	Carboxymethylated cellulose	Viscosity enhancer, disintegrant	Hydrophilic, improves dispersion	Sticky at high concentration
	EC / MC¹⁸	Alkyl cellulose	Film modifier, hydrophobicity adjuster	Controls film thickness, modulates release	Poor water solubility (EC)
Synthetic Polymers	PVA²⁸	Synthetic polymer (vinyl alcohol unit)	Main film former	Strong, flexible, clear Strip	Slow hydration, requires blending
Synthetic Polymers	PVP (K30, K90)²¹	Polyvinyl lactam	Solubilizer, co-former	Enhances dissolution via hydrogen bonding	Brittle without plasticizer
Modified Starches/ Polysaccharides	Maltodextrin²⁹	Hydrolyzed starch derivative	Co-former, disintegrant	Rapid dissolution, good mouthfeel	Hygroscopic
Modified Starches/ Polysaccharides	Pre-gelatinized Starch³⁰	Physically modified starch	Film former, binder	Cost-effective, easy hydration	Brittle Strip if used alone

2. Biopharmaceutics Classification System (BCS):

According to the Biopharmaceutics Classification System (BCS), drugs are categorized into four classes based on their solubility and permeability profiles. BCS Class II drugs, can be described as low solubility and high permeability which pose considerable difficulty in. formulation because of poor solubility which limits bioavailability. Improving the solubility and dissolution rate of such drugs is hence critical towards attainment of desired therapeutic. outcomes³¹. Strategies that have been used include solid dispersion, surfactant utilization, nanosizing and the. Hydrocolloid polymers have been widely used to incorporate hydrophilic polymers. overcome these limitations^32,33. Some methods and challenges faced in the process. Table 2 lists the preparation of orodispersible strip in brief.

Table 2: Techniques and major difficulties in preparation of orodispersible strip

Sr. No.	Technique	Useful In	Major Difficulties
1	Solvent Casting Method	Simple and versatile method for small to medium-scale production of ODFs	Solvent removal, long drying time, control of film thickness, possible drug degradation³⁴
2	Rolling Method	Large-scale production of uniform Strip	Uniform drug distribution, solvent evaporation control, equipment complexity³⁵
3	Hot Melt Extrusion Method	Continuous production, solvent-free process, suitable for poorly soluble drugs	High temperature may degrade drugs, specialized equipment, difficulty in controlling film thickness³⁶
4	Semisolid Casting Method	High drug load Strip, specific drug release profiles	Controlling gel mass consistency, drying time, film uniformity, complexity of polymer mixing³⁷

2.1 Orodispersible Strips of BCS Class II Drugs:

Polymeric network is the structural and functional backbone of orodispersible strips (ODS) and affects their mechanical integrity, disintegration characteristics and controlled drug delivery kinetics. Hydrocolloids are hydrophilic macromolecules - either natural, semi-synthetic or synthetic - which are capable of forming Strip when the solvent is evaporated. In formulations with Biopharmaceutics Classification System (BCS) Class II drugs, having low aqueous solubility and high membrane permeability, the polymer should be able to promote both rapid hydration and efficient drug release and acceptable mechanical properties and patient acceptability^37,38.

3. 3D Printing Technology:

There are a number of printing technologies that have been used in drug fabrication including fused deposition modeling (FDM), inkjet printing, semi-solid extrusion and stereolithography³⁹. In ODSs, 3D printing has unique benefits compared to traditional solvent casting or hot-melt extrusion methods 3D printing also decreases the amount of solvent left behind, gives uniform film thickness, and can be customized to a single-step process⁴⁰. In addition to this, it enables the incorporation of low dose APIs, multilayer designs, and combination regimens thus widening the range of the film-based formulations⁴¹.

Hydrocolloid-based polymer in combination with 3D printing technology is an exciting platform on which to develop BCS Class II drugs into orodispersible Strip. Hydrophilic properties of hydrocolloids (summarized in Table 3) increase the solubility and dispersion of insoluble drugs, and 3D printing guarantees the dosage accuracy, reproducibility, and flexibility of tailored treatment. These developments are in line with the current trend in precision medicine, which introduces new dosage forms, which are easily administered and effective medicines^42,43.

Table 3. Marketed formulation type along with polymer used

Drug Name	Marketed Name(s)	Formulation Type	Polymers Used
Ibuprofen⁴⁴	Advil®, Motrin®	Nanomicelles, Tablets	Soluplus® (PEG-polyvinyl caprolactam-polyvinyl acetate graft copolymer)
Ketoprofen⁴⁵	Orudis®, Oruvail®	Tablets, Nanoparticles	PLGA (poly (lactic-co-glycolic acid)
Telmisartan⁴⁶	Micardis®, Micardis Plus®	Tablets, ODF	Gelucire® (PEG-32 stearate), PVA, HPMC, PEG
Nifedipine⁴⁷	Adalat®, Procardia®	Extended-Release Tablets	PLGA, Eudragit E100, MCC (microcrystalline cellulose)
Enzalutamide⁴⁸	Xtandi®	Soft Gel Capsules	Labrasol® (non-ionic surfactant)
Olmesartan Medoxomil⁴⁹	Olmetec®	ODF	Polyvinyl alcohol (PVA), Hydroxypropyl methylcellulose (HPMC), PEG
Irbesartan⁵⁰	Aprovel®	ODF	PVA, HPMC, PEG
Valsartan⁵¹	Diovan®	ODF	PVA, HPMC, PEG
Candesartan Cilexetil⁵²	Atacand®	ODF	PVA, HPMC, PEG
Nebivolol⁵³	Nebistar®	ODF	PVA, HPMC, PEG
Ketorolac⁵⁴	Toradol®	Nanoparticles, Coatings	PLGA, Polyvinyl alcohol (PVA)
Ibuprofen⁵⁵ (Topical)	Nurofen®	Nanomicelles	Soluplus® (PEG–polyvinyl caprolactam–polyvinyl acetate graft copolymer)
Ketoprofen⁵⁶ (Microspheres)	Ketoprofen Lysine–PLGA Microspheres	Microspheres	PLGA (poly(lactic-co-glycolic acid))

3.1 Types of 3D Printing Technologies:

Additive manufacturing (AM), widely known as 3D printing, enables layer-by-layer fabrication of three-dimensional structures directly from computer-aided design (CAD) models. According to ASTM International Standard F2792-12a, 3D printing technologies, (summarized in Table 4) are divided into seven primary categories: binder jetting, directed energy deposition, material extrusion, material jetting, powder bed fusion, sheet lamination, and vat photopolymerization⁵⁷. Each of these technologies differs in its mode of material deposition, energy source, and range of compatible materials, influencing its suitability for pharmaceutical manufacturing - particularly in the fabrication of hydrocolloid-based orodispersible strip (ODS) designed to enhance the bioavailability of BCS Class II drugs^29,30.

3.1 Binder Jetting:

Binder jetting involves the selective deposition of a liquid binding agent onto a thin layer of powdered material, fusing particles together to create solidified layers. Successive layers are built to form the complete object, followed by post-processing such as drying or sintering to increase mechanical strength. Commonly used powders include metals, ceramics, polymers, and excipients like lactose, starch, or mannitol, while binders may consist of polymeric or aqueous solutions^58,59. This is a useful technique due to the ability to create highly porous structures that degrade quickly and is therefore useful in the development of orally disintegrating dosage forms. Another historic application of binder jetting in drugs is Aprecia Pharmaceuticals ZipDose® 3D printing technology, created by Aprecia Pharmaceuticals to manufacture Spritam® (levetiracetam)- the first 3D-printed and FDA-approved tablet⁶⁰. Even though binder jetting is simple, has scalability and can be used to control porosity, printed products tend to be weak in mechanical strength and require post-processing procedures that are unsuitable with hydrocolloid-based ODFs, which require flexible, continuous polymer matrices instead of powder-based constructs⁶¹.

3.2 Directed Energy Deposition:

Directed Energy Deposition (DED) is a high temperature additive manufacturing process whereby focused energy sources including lasers, plasma arcs or electron beams are directed at feedstock materials to melt them as they are deposited⁶². The feedstock is melted in place as either a powder or wire and solidifies into a layer when a layer has been formed. DED allows fine control of microstructure of materials and is used widely in the aerospace, defence and fabrication of biomedical implants⁶³. Although DED has outstanding capabilities in grain morphology and density, the harsh thermal conditions (usually above 1000C) and the demand on metallic materials make it miserable in pharmaceutical applications, especially of polymers or thermolabile drugs. Therefore, its applicability to orodispersible Strip or drug delivery system is insignificant because the conditions of processes cannot be compatible with pharmaceutical-grade hydrocolloids⁶⁴.

3.3 Material Extrusion:

One of the most popular types of 3D printing, also known as material extrusion, consists of two main subtypes, namely Fused Deposition Modeling (FDM) and Semi-Solid Extrusion (SSE)⁶⁵. In FDM, a thermoplastic filament, commonly filled with the active drug by hot-melt extrusion (HME) - is heated to a semi-molten state and forced through a nozzle to create layers which harden on cooling. Examples of common thermoplastic polymers are polyvinyl alcohol (PVA), polylactic acid (PLA) and hydroxypropyl methylcellulose (HPMC)⁶⁶. The technique enables the production of controlled release dosage forms with complicated geometries and internal frameworks. Nonetheless, its elevated processing temperatures (ranging between 100 -250⁰C) may destroy heat-sensitive drugs or biopolymers limiting its application on hydrocolloid-based ODFs that require low temperatures⁶⁷. Semi-Solid Extrusion (SSE) uses in contrast a viscous hydrogel or paste, which is extruded in layers at ambient or somewhat elevated temperatures (25 – 60⁰C). Alginate, gelatin, pullulan, carrageenan, and pectin, which are hydrocolloids that are used together with plasticizers, e.g., glycerol or sorbitol, yield appropriate rheological characteristics to extrusion^68,69. SSE allows uniform distribution of drugs, control of dosages, and custom film thickness with mild conditions that maintain thermolabile drugs. SSE is the most promising method 3D printing technique to hydrocolloid-based ODF fabrication due to its use with aqueous formulations and biocompatible polymers, particularly when using BCS Class II drugs, which need dissolution improvement⁷⁰.

3.4 Material Jetting:

Jetting Material jetting is similar to inkjet printing except that instead of ink, microscopic droplets of drugs solutions or suspensions are deposited on a substrate in a highly controlled fashion⁷¹. The droplets are driven out by either thermal inkjet (TIJ) by the formation of vapor bubbles or piezoelectric inkjet (PIJ) by mechanical movement of a piezoelectric crystal⁷². It is a process that enables fine regulation in the droplet size, spatial deposition and dose of drug and the solidification is fast through the action of solvent evaporation or polymerization under UV. Material jetting is specifically applicable to the individualized drug delivery systems because it is a room temperature process, and therefore, the danger is minimal in terms of thermal degradation. In the case of hydrocolloid-based ODSs, it is possible to print API layers onto already prepared hydrocolloid Strip, or co-deposit the drug and film-forming polymer at the same time⁷³. Even though it has great dose precision and scalability, the issues that need to be resolved include nozzle clogging, limited range of ink viscosities (1-30 mPa.s), and solvent compatibility⁷⁴. Nevertheless, material jetting through inkjet is one of the promising combinations of producing custom ODFs, especially in paediatric or geriatric preparations^75-77.

3.5 Powder Bed Fusion:

Selective Laser Sintering (SLS), Selective Heat Sintering (SHS) and Electron Beam Melting (EBM) fall under the umbrella category of Powder Bed Fusion (PBF), where focused energy is used to melt powder material in a layer-by-layer manner⁷⁸. The largest PBF technique used in pharmaceuticals is SLS, initially described by Carl Deckard in 1987⁷⁹. It uses polymer powders like PVP, Eudragit ® or PA12 which are sintered with a high-power laser to create solid matrices. The process has great resolution and mechanical characteristics but the intense laser energy can cause drugs degradation or melting of polymers, which reduces its ability to be compatible with sensitive APIs. Also, the stiff structures formed are not flexible enough to handle orodispersible films. Thus, ODF fabrication based on hydrocolloid is, to a large extent, incompatible with PBF although it finds application in solid tablets and implants^80,81.

3.6 Sheet Lamination:

Also known as Laminated Object Manufacturing (LOM), sheet lamination is a manufacturing process of stacking and welding together pre-shaped sheets of material, which are cut into desired form, and bonded together with adhesives, heat or ultra-sonic welding⁸². The operation has great build rate, low cost and low wastes. Nevertheless, because of its inferior accuracy, the adhesive application, and the lack of monolithic interlayers bonding, its pharmaceutical value is low. Theoretically, multi-layer ODSs with specific functionality like taste masking or modified release could be prepared by laminating edible polymeric sheets like HPMC or pullulan Strip, but in practice the complexity of the adhesive choice has prevented its use⁸³. Therefore, sheet lamination is not well studied in pharmaceutical ODF design as in comparison to other additive manufacturing methods.

3.7 Vat Photopolymerization:

The technologies of Vat Photopolymerization, such as Stereolithography (SLA) and Digital Light Processing (DLP) work on the principle of selective curing of photopolymer resins, in the presence of UV or visible light⁸⁴. A liquid resin that is in a vat is solidified in layers by either a laser beam (SLA) or a projected light pattern (DLP). These methods are characterized by high accuracy, smooth finish of the surface and complicated geometry. Nevertheless, the commonly used photo-curable monomers and photoinitiators are usually toxic and non-edible and therefore cannot be used in an oral drug formulation. Despite the extension of SLA and DLP to biocompatible photopolymers, enabling the broadening of these techniques to tissue scaffolds and dental devices, the application of these methods to hydrocolloid-based ODF fabrication is not much expands because of the safety and regulatory concerns^85,86.

Table 4: 3D Printing Techniques

3D Printing Technique	Working Principle	Common Materials	Pharmaceutical Applications	Relevance to Hydrocolloid-Based ODFs
Binder Jetting^1-3,6,87	Liquid binder selectively deposited onto powder bed to join particles layer-by-layer.	Metal, ceramic, polymer, sand powders; aqueous/polymeric binders.	Production of porous tablets (e.g., Spritam®, levetiracetam); rapid disintegration formulations.	Limited – produces brittle, powder-based structures unsuitable for flexible hydrocolloid Strip.
Directed Energy Deposition (DED)^8,14,88	Focused energy (laser/e-beam) melts feedstock powder/wire during deposition.	Metals, metal-polymer composites, ceramics.	Repair of metal parts, implants, aerospace tools.	Not suitable – extreme temperatures degrade hydrocolloids and APIs.
Material Extrusion (FDM / SSE)^4,5,24,31-33	Continuous extrusion of thermoplastic filament (FDM) or semi-solid paste (SSE) to form layers.	FDM: PLA, PVA, HPMC; SSE: Gelatin, alginate, carrageenan, pectin, pullulan.	Tablets, orodispersible Strip, implants, transdermal systems.	Highly suitable – SSE enables mild-temperature printing of hydrocolloid-based ODFs with precise dose control.
Material Jetting (Inkjet Printing)^40-45	Microdroplets of liquid formulation deposited via thermal or piezoelectric nozzles and solidified by drying or UV curing.	Drug-polymer solutions, hydrogels, UV-curable resins.	Personalized dosing, rapid prototyping, multilayer ODFs.	Highly suitable – precise deposition of APIs on or within hydrocolloid Strip; ideal for dose personalization.
Powder Bed Fusion (SLS / SHS / EBM)^46-49	Laser or electron beam selectively fuses powder particles layer-by-layer.	Polymers (PVP, Eudragit®), metals, ceramics.	Complex solid dosage forms, sustained-release matrices.	Limited – high temperature unsuitable for hydrocolloids; rigid outputs incompatible with flexible ODFs.
Sheet Lamination (LOM / UAM)^50,51	Pre-formed sheets bonded by adhesive, heat, or ultrasonic welding and cut to shape.	Paper, polymeric, or metallic sheets.	Structural and mechanical prototypes; conceptual pharmaceutical layering.	Marginal – may create multilayer ODFs but lacks precision and uniformity in drug distribution.
Vat Photopolymerization (SLA / DLP)^52-54	Photopolymer resin selectively cured by UV or visible light layer-by-layer.	Photo-curable monomers, biocompatible resins.	Dental prosthetics, tissue scaffolds, microneedles.	Unsuitable – photopolymer resins typically non-edible and toxic; limited use for oral dosage.

4. CONCLUSION:

Oral hydrocolloid-based orodispersible strip are a new and patient-centred oral drug. delivery system that provides rapid disintegration, ease of administration and better patient. compliance. Hydrocolloid polymers are incorporated and they give excellent film-forming. they are suitable because they contain properties, mechanical strength, and flexibility as well as a fast hydration in saliva. on paediatric, geriatric and dysphagic patients. The incorporation of a BCS Class II medication, marked by poor solubility and high permeability, also emphasizes the therapeutic. potential of this system. The application of the 3D printing technology permits the loading of drugs with high precision and uniformity. distribution and dose and film architecture customization. This approach enhances drug dissolution and bioavailability through augmenting surface area and facilitation of film design, therefore, circumventing the limitations to solubility of BCS Class II drugs.

In general, the orodispersible strip made of hydrocolloids and 3D printing is a combination. technology may be an effective delivery approach to the poorly soluble drugs. This novel platform delivers personalised medicine, enhanced curative results, and. is a major advancement in the development of pharmaceutical dosage forms of the modern era.

5. FUNDING:

Present work is supported by Research and Development Cell under University Research Project Scheme [grant number RTMNU/RDC/2024/269 dt. 15/01/2025] Rashtrasant Tukadoji Maharaj Nagpur, University, Nagpur.

6. ACKNOWLEDGEMENT:

The authors are highly thankful to the Agnihotri College of Pharmacy, Wardha for the constant support and encouragement.

7. CONFLICT OF INTEREST:

The authors declare no conflict of interest.

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Received on 19.01.2026 Revised on 28.03.2026

Accepted on 09.05.2026 Published on 20.05.2026

Available online from May 25, 2026

Research J. Pharmacy and Technology. 2026;19(5):2381-2389.

DOI: 10.52711/0974-360X.2026.00341

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