Proliposome-Based Delivery Strategies: Redefining Stability and Bioavailability
Lipid-based systems continue to revolutionize drug delivery. Yet, while conventional liposomes have proven indispensable, their instability, aggregation, and limited shelf life often constrain their broader adoption. Proliposomes—dry, free-flowing precursors that form liposomes upon hydration—have emerged as the next logical evolution, combining the precision of liposomes with the practicality of solid formulations.
At Creative Biolabs, our experts can help design and optimize custom proliposome formulations that address solubility, stability, and scalability challenges across diverse research needs.
Introduction of Proliposomes
From liposomes to proliposomes: a significant technological
advancement. Liposomes have long been valued for their biocompatibility and controlled-release properties. However, their liquid form makes them susceptible to various physical and chemical conditions, including aggregation, fusion, oxidation, and hydrolysis. Proliposomes solve these issues by storing lipids and actives in a dry, pre-liposomal state, forming stable vesicles only upon contact with aqueous media (Figure 1). This strategy provides not only enhanced shelf life and handling convenience but also allows precise in situ liposome formation—an advantage for oral, pulmonary, or transdermal delivery systems.
Fig.1 Formation of liposomes from proliposomes.1
What Are Proliposomes?
Proliposomes are typically dry powders comprising phospholipids, cholesterol, hydrophilic carriers, and solvents (Figure 2).
Phospholipids form the amphiphilic bilayer that defines liposomal architecture. Their dual hydrophilic–hydrophobic nature allows simultaneous entrapment of both water-soluble and fat-soluble molecules. The phospholipid bilayers are responsible for the membrane elasticity, particle uniformity, and encapsulation efficiency. Cholesterol and related derivatives in the phospholipid bilayer are responsible for the membrane fluidity and permeability. By increasing lipid packing, cholesterol prevents the leakage of hydrophilic actives and protects against disruptions caused by plasma components or changes in temperature. The carriers, which are porous and water-soluble particles, provide a large surface area that facilitates high lipid loading and enables rapid hydration upon contact with water. During production, organic solvents such as ethanol, methanol, chloroform, or diethyl ether are used temporarily to dissolve phospholipids and drugs, ensuring a uniform coating on the carrier surface. Their temporary inclusion provides membrane softness and promotes even lipid distribution during film formation.
Fig.2 Components used in proliposome preparation.6
Key formulation parameters:
In the proliposome preparation, the characteristics of the carriers are dictated by several key parameters.
- Carrier type and particle size: control surface area and coating efficiency.
- Lipid-to-drug ratio: determines vesicle size and drug-loading capacity.
- Hydration medium: affects vesicle morphology and release kinetics.
Key Advantages of Proliposome Systems
Compared to conventional liposomes, proliposomes have several advantages as carriers. Their dry and free-flowing characteristics lead to enhanced physical and chemical stability, which helps to prevent aggregation, oxidation, and leakage during storage. When hydrated, proliposomes can instantly and uniformly form liposomes, leading to high encapsulation efficiency and consistent maintenance of particle size. In addition, the integrated cholesterol enhances the rigidity of the bilayer, while water-soluble carriers such as mannitol or lactose facilitate rapid and controlled reconstitution. These systems are easy to handle, store, and transport without refrigeration and support scalable manufacturing through spray-drying or fluidized-bed coating. Collectively, proliposomes enable long shelf life, reproducible dosing, and enhanced bioavailability across diverse administration routes.
Table 1 Comparison between proliposomes and conventional liposomes.
| Feature | Conventional Liposomes | Proliposomes |
|---|---|---|
| Physical Form | Aqueous suspension | Dry powder |
| Stability | Moderate; prone to leakage | Excellent; long shelf life |
| Storage | Requires refrigeration | Room temperature feasible |
| Handling | Complex | Simple, scalable |
| Encapsulation Leakage | Frequent | Negligible until reconstitution |
Manufacturing and Formulation Strategies
Multiple scalable methods exist for proliposome preparation, each tailored to specific physicochemical properties of the payload:
1. Film Deposition on Carrier Method
- Lipid and drug dissolved in an organic solvent; evaporated onto the carrier surface.
- Advantage: simplicity and control over coating thickness.
2. Spray Drying
- Atomized lipid-drug mixture dried to powder.
- Advantage: suitable for heat-stable actives; high throughput.
3. Fluidized-Bed Coating
- Lipid film uniformly deposited on carrier particles in motion.
- Advantage: excellent uniformity and reproducibility.
4. Supercritical Anti-Solvent (SAS) Method
- Uses CO2 as an anti-solvent to precipitate lipid-drug complexes.
- Advantage: solvent-free, eco-friendly, and tunable particle morphology.
Regulatory and Commercialisation Considerations
Proliposome products must meet rigorous quality standards for research consistency:
- Physical tests: particle-size distribution, moisture content, flowability.
- Chemical tests: lipid oxidation index, encapsulation yield, residual solvent analysis.
- Reconstitution tests: vesicle uniformity, drug release profile, zeta potential.
At Creative Biolabs, every proliposome formulation undergoes a comprehensive Design-Analyze-Validate process:
- Design: selection of lipid composition and carriers based on drug physicochemistry.
- Analyze: advanced analytics using HPLC, DSC, FTIR, and dynamic light scattering.
- Validate: stability, hydration performance, and encapsulation reproducibility.
At Creative Biolabs, our scientists ensure your proliposome system meets GMP-ready standards for R&D and preclinical translation.
Practical Checklist (Use Internally with Your Team)
Before initiating a proliposome formulation project, teams should align on critical technical, analytical, and operational checkpoints. This practical checklist serves as an internal roadmap, ensuring formulation consistency, reproducibility, and compliance from concept through scale-up at Creative Biolabs.
- Define the route first (oral/DPI/topical).
- Pick the method (film, spray-dry, fluidized-bed, SCF) aligned with scale and API tolerance.
- Run DOE on lipid:carrier:drug ratios; map EE% vs release vs reconstitution size.
- Lock analytics early (powder + reconstituted specs).
- Plan stability for both powder (humidity excursions) and reconstituted liposomes (cold chain as needed).
Routes of Administration and Application Highlights
Proliposome-based formulations have evolved into multi-route delivery systems, capable of overcoming solubility, permeability, and stability barriers that limit conventional dosage forms. Their flexibility enables targeted, sustained, and bioavailable delivery through oral, pulmonary, transdermal, nasal, and parenteral routes. Each application leverages the proliposomal powder's dry, reconstitutable nature, forming liposomes in situ for localized or systemic release.
Oral Delivery
The oral route remains the most extensively studied and commercially viable application of proliposomes. As freely flowing powders or capsules, proliposomes rehydrate upon contact with gastrointestinal fluids to generate multilamellar liposomes that encapsulate poorly soluble drugs such as silymarin, domperidone, and nimodipine, achieving several-fold improvements in bioavailability.
Benefits:
The film deposition and spray-drying methods are most widely employed for oral proliposomes, offering scalability and uniform particle formation. Enhanced lymphatic uptake and bypassing of first-pass metabolism further contribute to their superior pharmacokinetic performance compared to conventional tablets or suspensions.
Pulmonary/Inhalation Delivery
Because proliposomes are compatible with natural lung surfactants and capable of forming liposomes upon aerosolization, they are considered a revolutionary advance in pulmonary drug delivery. When processed as dry powder inhalers (DPIs), pressurized metered-dose inhalers (pMDIs), or nebulized suspensions, they can be applied for localized delivery, prolonged lung retention, and reduced systemic toxicity.
Benefits:
Studies with levofloxacin and isoniazid proliposomes have demonstrated stable aerosolization profiles and controlled drug release for tuberculosis management. Moreover, the spray-dried proliposome technology can improve aerodynamic performance and moisture resistance, thus extending the shelf stability of therapeutic agents beyond 18 months.
Transdermal Delivery
Transdermal proliposomal gels are a highly promising alternative for sustained systemic absorption and localized drug targeting in transdermal administration. Upon hydration, phospholipid bilayers can merge with the skin's lipid matrix, thereby enhancing dermal permeation and fluidizing the stratum corneum.
Benefits:
Drugs such as metformin hydrochloride, repaglinide, and piroxicam have shown significantly improved skin permeability and anti-inflammatory activity when formulated in proliposomal gels. The sustained release of the medication is achieved through gradual diffusion across lipid layers. This process prolongs therapeutic availability, resulting in a reduced dosing frequency.
Nasal Delivery
Intranasal proliposomes can serve as effective systems for rapid absorption into the bloodstream and direct brain targeting, allowing the medication to bypass hepatic metabolism. A typical example is nicotine formulated with proliposomes, which have shown significantly prolonged plasma profiles.
Benefits: Their transformation into nanosized liposomes within the nasal mucosa enhances retention and enables non-invasive drug delivery to the CNS, offering opportunities in neuroactive and peptide-based molecule research.
Parenteral (Investigational)
For intravenous administration, proliposomes reconstitute into sterile liposomal dispersions that encapsulate cytotoxic or immunomodulatory compounds, such as methotrexate and ibuprofen.
Benefits: The controlled vesicle size and zeta potential improve physical stability, thus reducing aggregation risks during reconstitution. This platform enhances the circulation half-life and bioavailability of drugs with low water solubility or high membrane binding affinity, enabling safe and efficient systemic exposure.
Need a custom oral or pulmonary proliposome formulation?
Partner with our experts at Creative Biolabs to design a system tailored to your research model.
Future Perspectives
Proliposome research is expanding rapidly toward:
- Hybrid polymer-lipid constructs for dual release kinetics.
- AI-assisted formulation design for prediction of lipid-drug interactions and hydration rates.
- Green manufacturing using solvent-free or supercritical CO2 methods.
- Integration with microfluidic and continuous manufacturing systems for reproducible nano-scale control.
These trends indicate that proliposomes are not merely a bridge but a cornerstone in the future of lipid-based delivery science.
Creative Biolabs-Proliposome Development Workflow
Creative Biolabs provides an end-to-end workflow to plan, build, and validate niosome-based delivery—from surfactant selection and DoE to stability, scale-up, and CMC documentation. Our scientists tailor EE%, size/PDI, and release profiles to your route and payload so you can move from lab concept to manufacturable product with confidence.
Step 1: Feasibility Assessment
Evaluating API solubility, lipid compatibility, and hydration behavior.
Step 2: Prototype Formulation
Custom selection of lipid/carrier ratio, process route, and particle design.
Step 3: Analytical Characterization
Characterization of size, zeta potential, morphology, encapsulation, and moisture of proliposomes constructed.
Step 4: Scale-Up Optimization
Spray-drying or fluidized-bed coating under controlled humidity conditions.
Step 5: Data Reporting & Support
Full analytical dossier with recommendations for storage, handling, and downstream use.
To explore adjacent platforms and mix-and-match options, please visit our Module Delivery Systems page.
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FAQs
Is a proliposome the same as a dried liposome?
No. A proliposome is a precursor powder that transforms into liposomes upon hydration, offering longer stability than pre-formed liposomes.
What drug types are most compatible with proliposomes?
Lipophilic molecules (curcumin, aliskiren, and vinpocetine) and amphiphilic compounds benefit most. Peptides and flavonoids are also compatible when optimized.
Which carriers are commonly used?
Mannitol, maltodextrin, lactose, and microcrystalline cellulose—all ensuring uniform lipid deposition.
Can proliposomes be used for inhalation studies?
Yes. Spray-dried proliposomes are excellent for pulmonary delivery, generating vesicles in situ within lung fluid.
How long can proliposomes remain stable at ambient conditions?
Typically, over 18 months under < 30 % humidity, compared to 3-6 months for conventional liposomes.
What is the core difference between proliposomes and liposomes?
Proliposomes are powder precursors; liposomes are pre-formed vesicles in water. The powder is more stable and only forms vesicles when hydrated—either extemporaneously or in situ.
Do proliposomes actually improve oral bioavailability?
Yes—multiple studies report meaningful gains. For example, ginsenoside Rg3 proliposomes produced an ~11.8-fold increase in rat oral bioavailability vs control; aliskiren hemifumarate also showed improved absorption over the neat drug.
Are proliposomes suitable for inhalation as DPIs?
Yes. Spray-dried proliposomes have been engineered for curcumin and Amphotericin B; these powders rehydrate at the lung surface to form liposomes, improving deposition and residence while avoiding nebulizer shear.
Which manufacturing method should I choose?
Bench to pilot often starts with film deposition on the carrier. For DPI or industrial scale, spray-drying or fluidized-bed are favored; when solvent control is critical, consider SCF anti-solvent routes.
Conclusion
Proliposome-based delivery systems have transcended the traditional boundaries of liposomal technology. Their dry-state stability, high encapsulation efficiency, and broad route versatility make them ideal for formulating sensitive APIs and biopharmaceuticals.
At Creative Biolabs, we combine scientific rigor with customized innovation to help research partners design proliposome platforms tailored to their specific goals—whether for bioavailability enhancement, stability studies, or proof-of-concept development.
Contact our formulation specialists to start your project:
Explore Proliposome Formulation Services
References
- Dutta, A. & Borah, C. "Proliposomal Drug Delivery System: An Updated Review." International Journal of Trend in Scientific Research and Development 7, (2023). www.ijtsrd.com/papers/ijtsrd59692.pdf. Distributed under Open Access license CC BY 4.0, without modification.
- Hirenkumar Gajubhai Patel, Sanjay Kumar Jain, & Vijay Nigam. "Review of Proliposomal Gel for Transdermal drug delivery system." World J. Bio. Pharm. Health Sci. 14, 332–340 (2023). https://wjbphs.com/content/review-proliposomal-gel-transdermal-drug-delivery-system.
- Kunamaneni, P. et al. "Aliskiren Hemifumarate Proliposomes for Improved Oral Drug Delivery: Formulation Development, In Vitro and In Vivo Permeability Testing." Molecules 27, 4828 (2022). https://www.mdpi.com/1420-3049/27/15/4828.
- Ramteke, S., Gupta, V. & Barupal, A. "Formulation development and in vitro characterization of proliposomes for topical Delivery of aceclofenac." Indian J Pharm Sci 70, 768 (2008). http://www.ijpsonline.com/text.asp?2008/70/6/768/49119.
- Rojanarat, W., Nakpheng, T., Thawithong, E., Yanyium, N. & Srichana, T. "Levofloxacin-Proliposomes: Opportunities for Use in Lung Tuberculosis." Pharmaceutics 4, 385–412 (2012). https://www.mdpi.com/1999-4923/4/3/385.
- Prajakta Kangutkar, S. M. "A Review: Proliposomes As Effective and Stable Drug Delivery System." International Journal of Pharmaceutical Sciences 3, (2025). https://zenodo.org/doi/10.5281/zenodo.15352388. Distributed under Open Access license CC BY 4.0, without modification.
