In India, in ancient times, people used plant materials to make drug polyherbal formulations. Herbal drugs have enormous therapeutic potential which can be explored through various beneficial drug delivery systems and novel drug delivery systems. Great advancement has been made in the uses of plant therapeutics on the development of novel herbal formulations like polymeric nanoparticles, nanocapsules, liposomes, phytosomes, nanoemulsions, microsphere, transferosomes, and ethosomes. These formulations have reported having various advantages over the traditional formulations such as improved solubility and bioavailability, reduced toxicity, controlled drug delivery, protections of plant actives from degradation. Also, having the drug targeting properties with improved selectivity, drug delivery, and effectiveness with dose reduction not only increases the safety but also patient compliance.
Top1. Introduction
From time immemorial it has been the endeavour of the physician and the apothecary to provide patients with the best possible forms of medicines so that recovery from disease is faster and complete. The drugs are delivered in a suitable formulation keeping in view the safety, efficacy and acceptability among other factors, and the formulation is usually known as dosage form or drug delivery system. With the progress in all spheres of science and technology, the dosage forms have evolved from simple mixtures and pills to highly sophisticated technology intensive drug delivery systems, which are known as Novel Drug Delivery Systems (NDDS). (Mandal & Mandal, 2010) In the past few decades, considerable attention has been focused on the development of novel drug delivery system for herbal drugs. (Saraf, 2010) Herbal drugs are becoming more popular in the modern world for their application to cure variety of diseases with less toxic effects and better therapeutic effects. However, some limitations of herbal extracts/ plant actives like instability in highly acidic pH, liver metabolism etc. has led to drug levels below therapeutic concentration in the blood resulting in less or no therapeutic effect. Incorporation of novel drug delivery technology to herbal or plant actives minimizes the drug degradation or pre systemic metabolism and serious side effects by accumulation of drugs to the non targeted areas and improves the ease of administration in the paediatric and geriatric patients. (Goyal, et al., 2011) Conventional dosage forms including prolonged-release dosage forms are unable to meet the ideal prerequisites of novel carriers like ability to deliver the drug at a rate directed by the need of the body and to channel the active entity of herbal drug to the site of action.
For good bioavailability, natural products must have a good balance between hydrophilicity (for dissolving into the gastrointestinal fluids) and lipophilicity (to cross lipidic biomembranes). Many phytoconstituents like polyphenolics have good water solubility, but are, nevertheless, poorly absorbed (Manach, et al., 2004) either due to their multiple-ring large size molecules which cannot be absorbed by simple diffusion, or due to their poor miscibility with oil and other lipids, severely limiting their ability to pass across the lipid –rich outer membranes of the enterocytes of the small intestine. (Chauhan, et al., 2009)
Novel herbal drug carriers cure particular disease by targeting exactly the affected zone inside a patient's body and transporting the drug to that area. Novel drug delivery system is advantageous in delivering the herbal drug at predetermined rate and delivery of drug at the site of action which minimizes the toxic effects with increase in bioavailability of drugs. In novel drug delivery technology, control of the distribution of drug is achieved by incorporating the drug in carrier system or in changing the structure of the drug at molecular level. Incorporation of herbal drugs in the delivery system also aids to increase in solubility, enhanced stability, protection from toxicity, enhanced pharmacological activity, improved tissue macrophage distribution, sustained delivery and protection from physical and chemical degradation. For example, liposomes act as potential vehicles to carry anti cancer agents by increasing amount of drug in tumour area and decrease the exposure or accumulation of drug in normal cells/tissues thereby preventing tissue toxicity effects. The phytosomal carriers have been studied for effective delivery of herbal extracts of ginseng (Ginkgo biloba) etc. In the present chapter, an attempt has been made to touch upon various aspects and applications related to novel herbal drug formulations and its Effect of NDDS on Polyherbal formulation (Dhiman & Nanda et al., 2012).
In the past, almost all the medicines were from the plants; the plant being man’s only chemist for ages. Herbs are staging a comeback, herbal ‘renaissance’ is happening all over the globe and more and more people are taking note of herbal therapies to treat various kinds of ailments in place of mainstream medicine. (Sharma & Verma, 2016)