Advantages of Herbal Drugs and Topical Drug Delivery

Herbal formulations have been used for decades due to its enhanced activity and lesser side effects. India has a very long history of safe and continuous usage of many herbal drugs in the alternative system of health like ayurvedha, yoga, unani, siddha, homeopathy and naturopathy. Millions of Indians use herbal drugs regularly, as spices, home-remedies, health foods etc. Even allopathic system of medicine has adopted a number of plant derived drugs. These herbal drugs are used since ancient times and now a day there is a global recognition of plant potency which leads to the finding of herbal medicaments and are introduced into the market after successive preclinical and clinical trial. These are based on the fact that they are available from the nature itself in immense quantity to fulfill the needs of mankind. Due to the ability to cure a variety of disease with less side effects their value as medicament has increased day by day. Delivery of these herbal medicines can be only attained after suitable modification in order to produce sustained release and improved patient compliance. According to WHO about 80% of total world population depends upon herbal medicines.

While considering the better patient compliance and drug delivery there comes the importance of novel drug delivery system. Paul Ehrlich, in 1909, initiated the era of development for targeted delivery when he envisaged a drug delivery mechanism that would target directly to diseased cell. Conventional drug delivery involves the formulation of the drug into a suitable form, such as compressed tablet for oral administration or a solution for IV administration. These dosage forms have been found to have serious limitations while NDDS are developed to overcome the limitations of conventional drug delivery. A lot of novel drug carriers are available now a day such as niosomes, liposomes, nanoparticles, phytosomes and ethosomes. Novel drug carriers can be easily target the drug into the affected area inside the patient’s body and can produce better cure. They can be used to deliver the herbal drug in a predetermined rate. Incorporation of herbal drug in to a novel carrier rather than simply giving the herbal drug to the patient can also improve their solubility, stability, pharmacological activity, tissue macrophage distribution, sustained delivery, decreased toxicity and protection from physical and chemical degradation.

Advantages of herbal drugs

Less side effects: Herbal drugs are more secure to utilize and can be well tolerated by the patient. It have less unintended outcomes and less side effects than conventional medicines.

Better efficiency: Herbal medications are better for long-standing well-being that don’t react well to the conventional medicines.

Lower cost: Herbal drugs are relatively cheap compared to prescription medicines. Research, testing, and marketing add impressively to the cost of doctor prescribed drugs.

Widespread availability: herbal drugs are available allover without a prescription and it can be cultivate at the house itself, for e.g. peppermint.

Topical drug delivery

It is a localized drug delivery system in which the drug is directly applied to the skin of affected

area. Topical drug delivery system is mainly used for delivering drug for ophthalmic, vaginal,

rectal and dermatological uses. Skin is the best suitable organ for topical drug delivery.

Classification of topically applied dosage forms

Solids: Dusting powder

Semi-solids: Creams, Gel, Ointments, Paste

Liquids: Solution, Emulsion, Collodions, Lotion etc

Among them semi-solid preparations are much more useful to stick to the skin surface.

The skin

Skin is the largest organ of the body contributes about 20 square feet of the total area. The skin shields us from microorganisms and other components, prevention of ex¬cess water loss from the body , protection against external physical, chemical, and biologic invaders, regulate body temperature, and provide the sensation of touch, warmth, and cool.

Skin has three layers,

The epidermis: It is the outermost layer of skin composed of flat, squamous epithelial cells provides a waterproof barrier and makes the skin tone. Under the squamous cells, basal cells are present. These are made up of column cells. The epidermis is composed of about 4-5 layers. The outermost layer is stratum corneum composed of about 10 to 30 layers of polyhedral, dehydrated, flattened, keratinized cells. Most of the barrier functions of the epidermis confine to this layer. Next is the clear/translucent layer which forms the thicker part. Then comes to the granular layer in which keratinocytes lose their nuclei and their cytoplasm becomes granular. Other layers are immunologically active cells and located at the middle of this layer. Then comes to the basal/germinal layer and the Malpighian layer. The epidermis is separated from the dermis, by a basement membrane.

Dermis: The dermis is a layer of skin between the epidermis and subcutaneous tissues. These are made up of dense irregular connective tissue. It is divided into two layers, the superficial area adjacent to the epidermis called the papillary region and a profound thicker area known as the reticular dermis. Structural components of the dermis includes collagen, elastic fibers, and extrafibrillar matrix, hair follicles, sweat glands, sebaceous glands, apocrine glands, lymphatic vessels and blood vessels.

Hypodermis: It is the deeper part of the skin made up of fat and connective tissiue. The type of cells present in it includes fibroblasts, adipose cells, and macrophages. It is used mainly for fat storage.