INTRODUCTION:

Green nanotechnology is a branch of science that merges nanotechnology with environmental sustainability. It focuses on designing and producing nanomaterials and nanoproducts using eco-friendly processes, renewable resources, and non-toxic chemicals.

Unlike traditional nanotechnology, which may involve hazardous substances, green nanotechnology aims to reduce environmental harm during production and after use. In pharmaceutical sciences, green nanotechnology plays a vital role in developing safer and more effective drug delivery systems. By using natural sources like plant extracts, biodegradable polymers, and microorganisms to create nanoparticles, this approach helps improve drug targeting, absorption, and release. It also reduces side effects and increases patient safety. Sustainability in drug formulation has become increasingly important due to rising concerns about pollution, waste, and the impact of pharmaceutical residues on human health and the environment. Conventional drug manufacturing often involves toxic solvents and non-biodegradable materials¹. Green nanotechnology addresses these issues by promoting clean production methods, reducing chemical waste, and using biodegradable carriers. This not only protects the environment but also supports long-term public health and global ecological balance². Green nanotechnology also plays a crucial role in the evolution of personalized medicine. By designing nanocarriers tailored to an individual’s unique biological characteristics, therapies can be made more targeted and effective³. This approach supports the creation of theranostic platforms—systems that integrate both therapeutic and diagnostic functions. Using eco-friendly synthesis methods, such platforms are developed with biocompatible and non-toxic materials, enabling simultaneous treatment and real-time monitoring of diseases. From a sustainability standpoint, green nanomanufacturing emphasizes low-waste, energy-efficient techniques such as microwave-assisted, ultrasound-mediated, or enzyme-driven synthesis. These environmentally friendly approaches help lower harmful emissions and reduce the overall carbon footprint of pharmaceutical production^4,5.

Key advantages of green nanotechnology in pharmaceuticals include:

1. Targeted Drug Delivery: Nanocarriers engineered through green methods can be modified with ligands or surface charges to improve drug localization at disease sites, such as tumors or inflamed tissues, thereby reducing off-target effects.

2. Controlled Release Profiles: Biodegradable nanocarriers ensure a sustained or stimuli-responsive release of drugs, improving therapeutic efficacy and reducing dosing frequency.

3. Improved Solubility and Stability: Poorly water-soluble drugs can be formulated into nano-sized systems, enhancing their solubility, bioavailability, and shelf-life^6,7.

Green Nanomaterials: Sources and Properties:

Green nanomaterials are specially designed nanosized materials that are created using natural, renewable, and non-toxic substances. These materials are the foundation of green nanotechnology and offer both environmental and medical benefits. Their unique properties—such as small size, high surface area, and biocompatibility—make them ideal for pharmaceutical applications.

Plant-Based Nanoparticles:

Plants are rich sources of natural compounds that can act as reducing and stabilizing agents in nanoparticle synthesis. Extracts from leaves, roots, fruits, and flowers contain bioactive molecules like polyphenols, flavonoids, and alkaloids. These compounds help in converting metal ions into nanoparticles without the need for harsh chemicals⁸.

Figure 1: Plant-Based Nanoparticles

For example, silver or gold nanoparticles can be synthesized using neem or green tea extracts. These plant-based nanoparticles often show strong antioxidant, antibacterial, and anti-inflammatory properties, which are useful in drug delivery and wound healing.

Biopolymers and Biodegradable Nanocarriers:

Biopolymers are natural polymers obtained from biological sources such as starch, chitosan (from shellfish), alginate (from seaweed), gelatin, and cellulose. These are used to form biodegradable nanocarriers tiny systems that carry drugs safely to the target site in the body⁹.

Because biopolymers break down naturally and are non-toxic, they reduce the risk of side effects and environmental harm. They also improve drug stability and release patterns, making treatment more effective.

Eco-Friendly Synthesis Methods:

Green nanotechnology relies on synthesis methods that avoid the use of hazardous chemicals. Some of the most popular eco-friendly techniques include:

1. Green Synthesis: Uses natural products like plant extracts or microbial agents to create nanoparticles in a safe, simple way¹⁰.

2. Microwave-Assisted Synthesis: Speeds up the reaction using microwave energy, which reduces energy consumption and waste¹¹.

3. Ultrasound (sonochemical) Methods: Use sound waves to create nanoparticles, offering better control over size and shape¹².

4. Supercritical Fluid Technology: Involves using eco-friendly solvents like supercritical CO₂ for nanoparticle production without harmful by-products¹³.

These methods help minimize pollution, energy use, and toxicity, aligning with the goals of green chemistry and sustainable pharma development.

Sustainable Nanocarrier Systems for Drug Delivery:

Nanocarriers are tiny vehicles used to carry drugs to specific parts of the body. In green nanotechnology, these carriers are made using natural, biodegradable, and safe materials. This ensures not only effective treatment but also minimal harm to the environment. These sustainable nanocarriers improve how drugs are absorbed, distributed, and released, while reducing side effects.

Green Lipid-Based Nanoparticles:

Lipid-based nanoparticles are made using natural fats and oils. Two common types include:

1. Solid Lipid Nanoparticles (SLNs): These are made from solid lipids and are stable, non-toxic, and useful for controlled drug release.

2. Nanostructured Lipid Carriers (NLCs): These are a more advanced version, made from a mix of solid and liquid lipids. They offer better drug loading and flexibility.

Both SLNs and NLCs can be produced using green methods (like using plant-derived lipids or surfactants) and are ideal for delivering drugs like anti-inflammatory, anticancer, and antioxidant agents¹⁴.

Biodegradable Polymeric Nanoparticles:

These are made from natural polymers such as chitosan, alginate, or polylactic acid (PLA). They safely degrade in the body without leaving harmful residues. These nanoparticles help protect sensitive drugs from breaking down before reaching the target, and release the drug slowly over time¹⁵.

Biodegradable Polymeric Nanocarriers are Especially Useful for:

· Oral drug delivery

· Cancer treatment

· Vaccines

Their non-toxic nature makes them ideal for sustainable pharmaceutical formulations.

Case Studies: Herbal or Phytochemical-Based Nano Formulations:

Natural plant compounds like curcumin (from turmeric), quercetin (from fruits), and resveratrol (from grapes) often have poor solubility or stability in the body. Nanotechnology helps improve their effectiveness.

Examples:

· Curcumin-loaded nanoparticles have shown enhanced anti-cancer and anti-inflammatory effects.

· Green tea extract-based nanocarriers offer antioxidant and antimicrobial activity.

· Neem or tulsi (holy basil)-derived nanoparticles are being explored for antimicrobial and wound healing applications.

These case studies show how herbal compounds can be transformed into more effective treatments using green nanocarrier systems, combining traditional medicine with modern, eco-friendly technology.

Green Synthesis Approaches for Nanoparticles:

Green synthesis refers to the eco-friendly production of nanoparticles using natural biological materials instead of harmful chemicals. This approach aligns with the principles of green chemistry, aiming to reduce environmental impact, toxic waste, and energy usage during nanoparticle production. It is gaining popularity in pharmaceutical research for its safety, simplicity, and sustainability.

Use of Plant Extracts, Microbes, and Algae:

Green synthesis uses a variety of natural sources, including:

1. Plant extracts: Leaves, roots, fruits, or bark are rich in phytochemicals like flavonoids, alkaloids, and phenols. These compounds act as natural reducing and stabilizing agents during nanoparticle formation¹⁶.

Example: Neem, green tea, turmeric, and aloe vera have been used to synthesize silver and gold nanoparticles.

2. Microbes: Certain bacteria, fungi, and yeasts can reduce metal salts to nanoparticles through their enzymes and metabolic processes.

Example: Bacillus subtilis and Aspergillus niger are known to produce gold and silver nanoparticles.

3. Algae: Marine and freshwater algae are also used because they are rich in bioactive molecules.

Example: Spirulina and Chlorella have been used to synthesize zinc oxide nanoparticles.

These biological systems make the synthesis process safe, cost-effective, and suitable for large-scale production.

Advantages Over Chemical Synthesis:

Compared to traditional chemical or physical methods, green synthesis offers several benefits:

1. Non-toxic and Environmentally Safe: Avoids harmful chemicals and solvents.

2. Low cost: Uses readily available natural materials.

3. Simple and scalable: Doesn’t require high temperatures or pressures.

4. Biocompatible: The resulting nanoparticles are safer for human use.

5. Less Waste Production: Reduces hazardous by-products and energy consumption.

These green-synthesized nanoparticles have diverse pharmaceutical uses, including in creams, tablets, injectable drugs, and diagnostic tools^17,18.

Environmental and Toxicological Aspects:

Eco-toxicological Safety of Green Nanoparticles:

Green nanoparticles are designed to be safer alternatives to chemically synthesized nanoparticles. Since they are made using plant extracts, microbes, or biopolymers, they are expected to be less toxic to humans and the environment. However, this does not mean they are completely free of risk. Once these particles are released into the environment—during manufacturing, usage, or disposal—they may still interact with living organisms. For instance, they could affect aquatic life, soil bacteria, or even accumulate in plants and animals¹⁹. Therefore, detailed eco-toxicological studies are essential to understand how green nanoparticles behave in natural ecosystems. These studies help ensure that while the nanoparticles are used to improve health, they do not unintentionally harm the environment.

Biodegradability and Life-Cycle Assessment:

A key benefit of green nanomaterials is their biodegradability, which means they can naturally break down into non-toxic components after their use. For example, nanoparticles made from chitosan or starch are easily degraded by enzymes or microorganisms in the body or environment. This helps prevent long-term accumulation and pollution. To further assess the environmental impact of these materials, scientists use a method called Life Cycle Assessment (LCA). LCA examines the entire lifespan of a product—from raw material sourcing to manufacturing, usage, and final disposal. It helps identify which stages may have harmful environmental impacts and guides improvements in the production process. In the case of green nanoparticles, LCA supports the goal of creating pharmaceutical products that are not only effective but also sustainable from start to finish²⁰.

Regulatory Considerations and Challenges:

Despite their advantages, green nanoparticles face several regulatory hurdles. Currently, there are no specific international regulations tailored for green nanomaterials. Most guidelines were developed for conventional drugs or synthetic nanoparticles, which makes it difficult to classify or approve green nanoformulations²¹. Regulatory authorities like the FDA (U.S.), EMA (Europe), or CDSCO (India) require thorough data on safety, toxicity, stability, and efficacy before a new product is approved for human use—even if the product is made from natural sources. Another challenge is the lack of standardized testing protocols for green nanoparticles, which creates inconsistencies in how their risks are assessed. Additionally, public perception and awareness also play a role—some consumers may still be cautious about nanotechnology, regardless of how “green” it is. Therefore, it is important for researchers, regulators, and manufacturers to work together to build clear, science-based regulations that support innovation while ensuring safety²².

Applications in Sustainable Pharmaceutical Formulations:

Controlled Drug Release and Targeted Therapy:

Controlled drug release refers to the slow and steady release of a drug over a specific period, which helps maintain a consistent drug level in the body. This approach reduces the need for frequent dosing and improves patient compliance. Targeted therapy, on the other hand, involves directing the drug specifically to the site of disease—such as a tumor or inflamed tissue—while avoiding healthy cells. Green nanocarriers, like lipid-based or polymeric nanoparticles made from biodegradable materials, are ideal for these purposes. They can be engineered to respond to pH, temperature, or enzymes at the target site, ensuring the drug is released only where it is needed. This precision reduces side effects and enhances therapeutic efficiency, especially in cancer and chronic disease treatments²³.

Improved Bioavailability and Stability:

Many drugs, especially those derived from natural sources like herbs or plant compounds, face challenges such as poor solubility, low absorption, or instability in the body. When these drugs are incorporated into green nanoparticles, their bioavailability—the amount of drug that reaches the bloodstream—increases significantly. For instance, curcumin (from turmeric) is poorly absorbed on its own, but when loaded into nanoparticles, it becomes much more effective. Additionally, nanocarriers protect the drug from degradation by light, heat, or stomach acids, improving its stability. This ensures that the drug retains its potency until it reaches its target, allowing for better clinical results with smaller doses.

Examples:

Green nanotechnology has been successfully applied to enhance the effectiveness of various therapeutic agents:

Anticancer agents such as curcumin, paclitaxel, and resveratrol have been formulated into green nanoparticles to improve their targeting to tumor cells, increasing treatment efficacy while minimizing damage to healthy tissues²⁴.

Figure: 2 Action of nano-carriers on cancerous cell

· Anti-inflammatory drugs like quercetin and boswellic acid have shown enhanced absorption and reduced side effects when delivered using plant-based nanocarriers.

· Antimicrobial agents including silver and zinc oxide nanoparticles synthesized using natural extracts (like neem or green tea) are widely used in creams, wound dressings, and coatings due to their strong antibacterial and antifungal properties²⁵.

CHALLENGES AND LIMITATIONS:

Standardization and Reproducibility Issues:

One of the biggest challenges in green nanotechnology is achieving standardization and reproducibility. Since green synthesis often involves natural materials like plant extracts, algae, or microbes, the exact chemical composition of these materials can vary based on the season, geographical location, or extraction methods. This variability can affect the size, shape, and stability of the nanoparticles produced. As a result, producing identical batches of nanoparticles consistently becomes difficult, which is a major concern in pharmaceutical manufacturing where uniformity and precision are critical. Without standardized protocols, it is challenging to ensure that each formulation performs the same way in every dose^26,27.

Regulatory Barriers:

Green nanotechnology is still a relatively new field, and regulatory frameworks specific to these products are limited. Most current drug approval systems are based on conventional pharmaceuticals and synthetic nanomaterials. As a result, there is confusion about how to classify, test, and approve green nanoformulations, especially those made from plant-based or biological sources. Regulators like the FDA, EMA, or CDSCO require comprehensive data on safety, toxicity, stability, and manufacturing quality. But due to the lack of standardized methods for green nanoparticles, fulfilling these regulatory requirements becomes a challenge. This slows down the clinical translation and approval of promising green nanodrugs.

Scale-Up and Cost Challenges:

Another major limitation is the difficulty in scaling up laboratory-scale green synthesis methods to industrial levels. Green synthesis processes, such as using plant extracts or microbial cultures, may work well in small quantities but become less efficient or more complex when scaled up for mass production. Maintaining quality control and consistency during large-scale manufacturing is often difficult. Additionally, the cost of purification, stabilization, and formulation of green nanoparticles can be high. These economic factors limit the commercial viability of green nanoproducts and may discourage investment in large-scale production unless the processes become more cost-effective and industrially feasible^28,29.

Future Perspectives and Research Directions:

AI and Green Nanotech Integration:

The future of green nanotechnology is expected to be greatly influenced by artificial intelligence (AI). AI tools can accelerate the design, testing, and optimization of nanoparticles by analyzing large datasets and predicting outcomes with high accuracy. For example, machine learning algorithms can help determine the best combination of plant extract, temperature, and pH to produce nanoparticles of the desired size and shape. This can save time, reduce trial-and-error experimentation, and make green synthesis more efficient. Additionally, AI can assist in forecasting toxicity, stability, and biological interactions, which helps in meeting regulatory standards faster. Integrating AI with green nanotech will not only speed up research but also improve the reproducibility and scalability of sustainable formulations.

Smart Biodegradable Systems:

Next-generation drug delivery systems are moving toward smart biodegradable nanocarriers that can respond to specific biological signals such as pH, temperature, enzymes, or oxidative stress. These systems can release drugs only when and where they are needed, enhancing therapeutic outcomes while reducing side effects. For instance, a nanoparticle made from biodegradable polymers may stay intact in the bloodstream but release its drug payload upon entering a tumor with an acidic microenvironment. Such “on-demand” drug release systems offer high precision and align with sustainability goals, as they degrade naturally after completing their function, leaving no harmful residues in the body or environment³⁰.

Global Strategies for Greener Pharmaceutical Innovation:

To ensure green nanotechnology grows responsibly and reaches its full potential, global collaboration is crucial. This includes creating standardized guidelines for the production, testing, and approval of green nanoformulations. International partnerships between academia, industry, and regulatory bodies can lead to the development of eco-certifications, incentives for sustainable innovation, and support for low-cost green technologies in developing countries. There is also a growing push for pharmaceutical companies to adopt green chemistry principles across their R&D and manufacturing pipelines. In the future, governments and global health organizations may play a key role in promoting environmentally friendly drug development through policy, funding, and public-private partnerships.

CONCLUSION:

Green nanotechnology represents a transformative approach in pharmaceutical sciences, combining the principles of sustainability, safety, and innovation. This review highlighted how green synthesis methods using plant extracts, microbes, and eco-friendly materials are redefining nanoparticle production by minimizing environmental impact and enhancing biocompatibility. The emergence of biodegradable nanocarriers and smart delivery systems has improved the precision and effectiveness of drug delivery, especially in treating chronic diseases like cancer and infections.Despite its many advantages, green nanotechnology still faces challenges such as lack of standardization, regulatory hurdles, and scale-up limitations. However, advancements in artificial intelligence, responsive biodegradable systems, and global policy shifts are paving the way for smarter, safer, and more sustainable pharmaceutical innovations.In conclusion, the integration of green nanotechnology into pharmaceutical formulations is not just an alternative—it is a necessity in the pursuit of safer healthcare and a cleaner planet. With continued research, collaboration, and responsible commercialization, green nanotech has the potential to revolutionize the future of medicine.

REFERENCES:

1. Gour A, Jain NK. Advances in green synthesis of nanoparticles. Artificial cells, nanomedicine, and Biotechnology. 2019 Dec 4; 47(1): 844-51.

2. Nadaroglu H, Güngör AA, Ince S. Synthesis of nanoparticles by green synthesis method. International Journal of Innovative Research and Reviews. 2017 Aug; 1(1): 6-9.

3. Alghamdi MA, Fallica AN, Virzì N, Kesharwani P, Pittalà V, Greish K. The promise of nanotechnology in personalized medicine. Journal of Personalized Medicine. 2022 Apr 22; 12(5): 673.

4. Jamalipour Soufi G, Iravani S. Eco friendly and sustainable synthesis of biocompatible nanomaterials for diagnostic imaging: current challenges and future perspectives. Green Chem. 2020; 22: 2662 87..

5. Bilal M, et al. Synthesis of green nanoparticles for energy, biomedical, environmental, agricultural, and food applications: a review. Environ Chem Lett. 2023; 21.

6. Alfei S. Nanotechnology applications to improve solubility of bioactive constituents of foods for health-promoting purposes. InNano-food Engineering: Volume One 2020 Aug 7 (pp. 189-257). Cham: Springer International Publishing.

7. Shah P, Goodyear B, Michniak-Kohn BB. A review: enhancement of solubility and oral bioavailability of poorly soluble drugs. Adv Pharm J. 2017;2(5):161-73.

8. Hano C, Abbasi BH. Plant-based green synthesis of nanoparticles: Production, characterization and applications. Biomolecules. 2021 Dec 25; 12(1): 31.

9. Kučuk N, Primožič M, Knez Ž, Leitgeb M. Sustainable biodegradable biopolymer-based nanoparticles for healthcare applications. International Journal of Molecular Sciences. 2023 Feb 6; 24(4): 3188.

10. Jeevanandam J, Kiew SF, Boakye-Ansah S, Lau SY, Barhoum A, Danquah MK, Rodrigues J. Green approaches for the synthesis of metal and metal oxide nanoparticles using microbial and plant extracts. Nanoscale. 2022; 14(7): 2534-71.

11. Grewal AS, Kumar K, Redhu S, Bhardwaj S. Microwave assisted synthesis: a green chemistry approach. International Research Journal of Pharmaceutical and Applied Sciences. 2013 Oct 31; 3(5): 278-85.

12. Duan H, Wang D, Li Y. Green chemistry for nanoparticle synthesis. Chemical Society Reviews. 2015;44(16):5778-92.

13. Sheth P, Sandhu H, Singhal D, Malick W, Shah N, Serpil Kislalioglu M. Nanoparticles in the pharmaceutical industry and the use of supercritical fluid technologies for nanoparticle production. Current Drug Delivery. 2012 May 1; 9(3):269-84.

14. Akhlaghi S, Rabbani S, Alavi S, Alinaghi A, Radfar F, Dadashzadeh S, Haeri A. Green formulation of curcumin loaded lipid-based nanoparticles as a novel carrier for inhibition of post-angioplasty restenosis. Materials Science and Engineering: C. 2019 Dec 1; 105: 110037.

15. Kumari A, Yadav SK, Yadav SC. Biodegradable polymeric nanoparticles-based drug delivery systems. Colloids and surfaces B: biointerfaces. 2010 Jan 1;75(1):1-8.

16. Burlacu E, Tanase C, Coman NA, Berta L. A review of bark-extract-mediated green synthesis of metallic nanoparticles and their applications. Molecules. 2019 Nov 28;24(23):4354.

17. Parveen K, Banse V, Ledwani L. Green synthesis of nanoparticles: Their advantages and disadvantages. InAIP Conference Proceedings 2016 Apr 13 (Vol. 1724, No. 1). AIP Publishing.

18. Abdussalam-Mohammed W, Ali AQ, Errayes AO. Green chemistry: principles, applications, and disadvantages. Chem. Methodol. 2020 Jun; 4(4): 408-23.

19. Corsi I, Venditti I, Trotta F, Punta C. Environmental safety of nanotechnologies: The eco-design of manufactured nanomaterials for environmental remediation. Science of The Total Environment. 2023 Mar 15; 864: 161181.

20. Pati P, McGinnis S, Vikesland PJ. Life cycle assessment of “green” nanoparticle synthesis methods. Environmental Engineering Science. 2014 Jul 1; 31(7): 410-20

21. Albrecht MA, Evans CW, Raston CL. Green chemistry and the health implications of nanoparticles. Green Chemistry. 2006; 8(5): 417-32

22. Casals E, van Leeuwen C, Pujalt E, Puntes V. Regulatory issues in nanotechnology. Environ Int. 2021; 149: 106418.

23. Jahangirian H, Lemraski EG, Webster TJ, Rafiee-Moghaddam R, Abdollahi Y. A review of drug delivery systems based on nanotechnology and green chemistry: green nanomedicine. International Journal of Nanomedicine. 2017 Apr 12:2957-78

24. Elbialy NS, Abdelfatah EA, Khalil WA. Antitumor activity of curcumin-green synthesized gold nanoparticles: In vitro study. BioNanoScience. 2019 Dec; 9:813-20

25. Widatalla HA, Yassin LF, Alrasheid AA, Ahmed SA, Widdatallah MO, Eltilib SH, Mohamed AA. Green synthesis of silver nanoparticles using green tea leaf extract, characterization and evaluation of antimicrobial activity. Nanoscale Advances. 2022; 4(3): 911-5

26. Abegunde SM, Afolayan BO, Ilesanmi TM. Ensuring Sustainable Plant-Assisted Nanoparticles Synthesis through Process standardization and reproducibility: Challenges and Future Directions–A Review. Sustainable Chemistry One World. 2024 Jun 24: 100014

27. Shahzadi S, Fatima S, Qurat-ul-Ain, Zunaira S, Janjua MRSA. A review on green synthesis of silver nanoparticles (SNPs) using plant extracts: a multifaceted approach in photocatalysis, environmental remediation, and biomedicine. RSC Adv. 2025; 15: 1234–56.

28. Ahmed SF, Mofijur M, Rafa N, Chowdhury AT, Chowdhury S, Nahrin M, Islam AS, Ong HC. Green approaches in synthesising nanomaterials for environmental nanobioremediation: Technological advancements, applications, benefits and challenges. Environmental Research. 2022 Mar 1; 204: 111967.

29. Singh P, Pandit S, Wu H-F. Plant and microbial approaches as green methods for the synthesis of nanomaterials: synthesis, applications, and future perspectives. Appl Microbiol Biotechnol. 2023; 107(7): 2587–2602.

30. Aswathi VP, Meera S, Maria CA, Nidhin M. Green synthesis of nanoparticles from biodegradable waste extracts and their applications: a critical review. Nanotechnology for Environmental Engineering. 2023 Jun; 8(2): 377-97.

Received on 16.07.2025 Revised on 18.09.2025

Accepted on 02.11.2025 Published on 13.04.2026

Available online from April 15, 2026

Asian J. Pharm. Tech. 2026; 16(2):171-176.

DOI: 10.52711/2231-5713.2026.00024

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Creative Commons License.