The purchase of drugs employs an increasingly large part of the health budget of many Third World countries. Like health care expenditure as a whole, drug spending is heavily biased in favour of urban hospitals, often for expensive proprietary drugs that offer little benefit over cheaper preparations. As a result, because limited funds are available, vaccines and drugs for prevention and primary care are sometimes unavailable, especially in rural areas. The World Health Organization and many individual countries have responded to the problem of drug costs by creating a limited list of drugs considered essential for health care needs. Other methods of curtailing spending on drugs have included tendering for supplies and the establishment of plants to manufacture and formulate drugs. Controls of this type meet enormous resistance from doctors and pharmaceutical manufacturers, but are vital for the implementation of policies for appropriate health care.