The preclinical studies for drug screening involve the use of animals which is very time consuming and expensive and at times leads to suffering of the used organism. Animal right activists around the world are increasingly opposing the use of animals. This has forced the researchers to find ways to not only decrease the time involved in drug screening procedures but also decrease the number of animals used and also increase the humane care of animals. To fulfill this goal a number of new in vitro techniques have been devised which are called ‘Alternatives’ or ‘Substitutes’ for use of animals in research involving drugs. These ‘Alternatives’ are defined as the adjuncts which help to decrease the use as well as the number of animals in biomedical research. Russell and Burch have defined these alternatives by three R's - Reduction, Refinement and Replacement. These alternative strategies include physico-chemical methods and techniques utilizing tissue culture, microbiological system, stem cells, DNA chips, micro fluidics, computer analysis models, epidemiological surveys and plant-tissue based materials. The advantages of these alternatives include the decrease in the number of animals used, ability to obtain the results quickly, reduction in the costs and flexibility to control the variables of the experiment. However these techniques are not glittering gold and have their own shortcomings. The disadvantages include the lack of an appropriate alternative to study the whole animal's metabolic response, inability to study transplant models and idiosyncratic responses and inability to study the body's handling of drugs and its subsequent metabolites. None-the-less these aalternative methods to certain extent help to reduce the number of animals required for research. But such alternatives cannot eliminate the need for animals in research completely. Even though no animal model is a complete set of replica for a process within a human body, the intact animal does provide a better model of the complex interaction of the physiological processes.

Ethnobotanical plants have been used in the treatment of various diseases since antiquity. The phytoconstituents have pharmacological activities such as anti-tumor, anti-inflammatory, antinociceptive, anti-obesity, thermoregulatory effects, cardioprotective, anti-asthmatic, anti-diabetic, anti-oxidant, hepatoprotective and potent CNS activities. Various drug delivery systems like liposomes, niosomes, transferosomes, ethosomes, phytosomes, colloidosomes etc. are developed in order to carry the drug to the site of action without its metabolism. The major concern with respect to phytoconstituents having different chemical nature is its bioavailability and effective dosage concentration which could be overcome by means of phytosome technology. Chemically, phytosomes are vesicles of phospholipids bonded with a hydrogen bond to phytochemical/s. The current review highlights the major therapeutic applications of phytosomes till date. The review discusses about a latest and novel drug delivery system viz. "Phytosome technology" whereby major emphasis has been provided on the different therapeutic applications of phytosomes and its crucial role in managing the conventional complications that are encountered for the delivery of phytoconstituents. Applications of phytosomes such as enhancing bioavailability, anti-cancer and anti-oxidant agent, transdermal delivery, wound healing capacity etc. have been discussed. The comparison between the therapeutic activities of free drug and its phytosomes indicates that the complex provides various advantages over the conventional treatments.