The discovery and development of new drugs to provide medicines for treating diseases is the main role of the pharmaceutical industry. It is a challenging and expensive activity of pharmaceutical industry. Biological organisms and especially human beings are extraordinarily complex, and our understanding of how they function at the molecular level remains rudimentary, although considerable advances in knowledge have been made in recent decades. Whilst an advanced industrial society was able to plan and deliver a man to the moon following a 10-year program, almost 50 years on we are still only able to treat about 60% of cancer patients effectively, and do not understand how to correct most mental diseases. Development of new medicines is complex, time consuming and very expensive. The average cost of developing a new drug is estimated to be about US $ 1-1.2 billion, including expenditures on failed projects. This amount is about four times the price of an Airbus A380 at US $ 270 million
Experiments on animals are necessary for drug discovery and development as well as to advance pharmaceutical, medical and biomedical research. The best means to extrapolate from animal dose to human dose or human dose to animal dose has been an area of interest in experimental pharmacology for a number of years. Dosage calculation and stock solution preparation based on dosage rationale formula are prerequisites to drug administration in experimental animals also have the utmost importance. 1) Calculate the dose for experimental animals The human or animal dose that is given to other animals is on the basis of weight or relative surface area. It has been argued that body surface area (BSA) provides a more accurate basis for dose calculation, because total body water, extracellular fluid volume, and metabolic activity are better paralleled by BSA. If the dose of a drug for an animal is unknown then it may be converted from human doses or other animal doses with the help of appropri