Nano Herbal Drug Delivery System: Bridging Ayurveda and Nanotechnology

Ayurveda emphasizes holistic health using natural plant-derived substances. Herbal medicines are widely recognized for their therapeutic potential, minimal side effects, and cultural acceptance. However, limitations such as poor solubility, low bioavailability, instability, and lack of target specificity restrict clinical efficacy.

Nanotechnology, dealing with particles sized 1–100 nanometers, offers strategies to enhance solubility, stability, controlled release, and targeted delivery of phytochemicals. Integration of Ayurveda with nanotechnology has led to Nano Herbal Drug Delivery Systems (NHDDS), improving therapeutic outcomes and global acceptance.

India, known as the “Botanical Garden of the World,” has a rich legacy of medicinal plant knowledge. Phytochemicals produced by plants exhibit antibacterial, antifungal, antioxidant, and anticancer effects. Despite these advantages, herbal drugs often face reduced bioavailability due to poor solubility, low absorption, and lack of target specificity.

This review provides a comprehensive overview of NHDDS, highlighting their potential to overcome conventional herbal medicine limitations and integrate traditional Ayurveda with modern nanotechnology.

Ayurveda: Historical Background and Significance:

Ayurveda, often referred to as the “Science of Life,” is an ancient system of medicine that originated in India over 5000 years ago. It encompasses a holistic approach to health and well-being, emphasizing the balance between the mind, body, and spirit. Its roots are deeply embedded in the Vedic scriptures, including the Atharva Veda, Rig Veda, and Yajur Veda, where early references to medicinal plants, healing practices, and lifestyle management can be found. Over the centuries, Ayurveda has evolved into a comprehensive medical system with well-documented principles for diagnosis, prevention, and treatment of diseases. Central to Ayurveda is the concept of Panchakarma, a series of detoxification procedures designed to cleanse and rejuvenate the body, mind, and consciousness. Ayurveda also identifies five basic elements (Panchamahabhutas)—earth, water, fire, air, and ether—which combine in varying proportions to form the three doshas: Vata, Pitta, and Kapha. These doshas regulate the physiological, mental, and emotional functions of the human body. Each dosha has five sub-doshas that govern specific bodily functions, such as circulation, digestion, metabolism, and cellular activities. Ayurveda not only emphasizes herbal remedies but also incorporates diet, lifestyle, yoga, meditation, and therapeutic procedures to maintain health and prevent disease. Its holistic approach considers individual constitution (Prakriti), environmental factors, and seasonal variations in health management. The knowledge of medicinal plants in Ayurveda has been instrumental in the development of modern pharmacology. Historical texts describe the preparation of herbal formulations, identification of active phytochemicals, and their therapeutic applications.

Ayurvedic knowledge of medicinal plants has been crucial throughout human evolution. Notable plant-derived drugs include

1. Digoxin from Digitalis spp.
2.  Quinine and quinidine from Cinchona spp.,
3. Vincristine and vinblastine from Catharanthus roseus
4.  Atropine from Atropa belladonna
5. Morphine and codeine from Papaver somniferum.

Phytochemicals and Herbal medicines in Ayurveda :

Ayurveda makes extensive use of medicinal plants such as:

• Curcuma longa (Turmeric): Known for its antioxidant and anti- inflammatory effects.
• Withania somnifera (Ashwagandha): Acts as an adaptogen and   supports neurological health.
• Ocimum sanctum (Tulsi): Possesses antimicrobial and immune -enhancing properties .
• Azadirachta indica (Neem): Exhibits strong antibacterial and antiparasitic activity.
• Tinospora cordifolia (Guduchi): Recognized for its immune  boosting potential.

These herbs contain a wide range of active phyto constituents, including alkaloids, flavonoids, terpenoids, and glycosides. However, “Their therapeutic benefits are often constrained by challenges related to absorption, stability, and bioavailability.”

Nanotechnology in drug delivery:

Nanotechnology entails the manipulation and control of materials at the nanoscale, generally between 1 and 100 nanometers . It provides distinctive properties and functionalities that can be leveraged to optimize drug delivery systems. In the realm of herbal medicine, nanotechnology-based drug delivery systems offer the potential to enhance the absorption, distribution, and targeted release of bioactive compounds derived from herbal sources.

Nanoparticles (NP) are colloidal drug delivery systems composed of natural, synthetic, or semi-synthetic polymers. Nanoparticles are classified according to their dimensionality, morphology, physical state, and chemical composition. They represent a unique category of nanomaterials in the field of nanotechnology and are generally characterized by particle sizes ranging from 10 to 100 nm.

Nanoparticles can be broadly categorized into various types, including:

1. Solid Lipid Nanoparticles (SLNs)

2. Liposomes

3. Nanostructured Lipid Carriers (NLCs)

4. Fullerenes

5. Nanoshells

6. Quantum Dots

7. Superparamagnetic Nanoparticles

Nisosomes:

Niosomes represent a novel drug delivery system where the drug is encapsulated within vesicular structures. These vesicles consist of a bilayer formed by non-ionic surfactants, which is why they are termed niosomes. They are extremely small in size and exist at the microscopic scale.

Microspheres:

Microspheres are spherical particles with a typical size range of 200–500 µm, usually composed of proteins or biodegradable synthetic polymers. Various preparation techniques allow precise control over drug delivery, thereby enhancing therapeutic outcomes. By utilizing microspheres, many limitations associated with conventional therapies can be addressed, leading to improved drug effectiveness.

Liposomes:

A liposome is a microscopic vesicle in which an aqueous core is entirely enclosed by a lipid bilayer membrane. Also referred to as vesicles or colloidal spheres, liposomes are composed of cholesterol, non-toxic surfactants, sphingolipids, glycolipids, long-chain fatty acids, membrane proteins, and therapeutic agents. Their characteristics vary significantly depending on lipid composition, surface charge, particle size, and method of preparation. Moreover, the bilayer’s rigidity, fluidity, and charge are determined by the specific components incorporated into its structure.

Nanoemulsion:

Nanoemulsions represent one of the most efficient dispersed nanosystems, with droplet sizes extending into the submicron range. Also referred to as sub-micron emulsions (SMEs) or mini-emulsions, they are thermodynamically stable, transparent or translucent systems consisting of oil and water. These dispersions are stabilized by an interfacial layer composed of surfactant and co-surfactant molecules, and typically possess droplet sizes smaller than 100 nm.

Applications of Nano- herbal formulations :

Recent studies demonstrate improved therapeutic efficacy by using nanocarriers for herbal extracts:

• Curcumin nanoemulsions exhibit enhanced antioxidant and anti-inflammatory effects due to increased solubility and stability.
• Ashwagandha loaded in polymeric nanoparticles shows improved neuroprotective activity by better blood-brain barrier penetration.
• Tulsi Nano formulations enhance antimicrobial and immunomodulatory properties.
• Neem solid lipid nanoparticles offer targeted antibacterial and     antimalarial delivery.

Such systems significantly boost pharmacological action and patient adherence due to reduced dosing frequency, minimized side effects, and seamless integration with modern medical standards.

Comparison of herbal bioactive and their nanocarrier -mediated delivery benefits: