Pharmaceuticals are industries that are licensed for development, production and marketing and distribution of medical drugs. The science of drugs is known as pharmacology. Pharmacy refers to both the practice of preparing and dispersing drugs. An individual who qualified in this area of pharmacology is called as a pharmacist or chemist. Pharmacist can advise on a particular drug for related minor ailments, some medicinal drugs known as controlled substances are only made available. Prescription is a written and signed instruction from a Doctor that authorize the chemist to dispense the controlled substance to the patient. Prescriptions include name and dosage of the drugs and other relevant instructions.