An overview on natural product drug formulations from conventional medicines to nanomedicines: Past, present and future

For decades, naturally produced plants have been studied and used in herbalism (herbal medicines). Despite being natural, these products were not of any interest of any of the major pharmaceutical companies. There are various reasons behind this ignorance but mainly because of the outdated thought, that many people believe about natural products, in which plants are only utilized for their antibiotic benefits since there were successfully used as antibiotics in the post-World War II era. Mainly small pharmaceutical companies have paid attention to natural products and explored their benefits against various diseases such as microbial infection, cancer, cardiovascular diseases, diabetes and other illnesses while big pharmaceutical industries have focused on screening synthetic compounds. Nowadays, natural products and their derivatives have demonstrated their significant impact as therapeutic agents on people heath. Accordingly, about one-third of the top-selling products in the pharmaceutical market are natural products which are either derived from plants or microorganisms. The use of such products is highly preferred by people due to their unique advantages of good therapeutic efficacy, low side effects and cheaper than synthetic products. However, many of natural products are not clearing the clinical trials due to their toxicity and problems with biocompatibility. This review will briefly highlight the history of herbal medicine and will cover pharmaceutical formulations prepared from therapeutically active extracts of natural products. In addition, this article will summarise a range of natural products in conventional dosage forms to the most recent nano-medicinal forms.