Drugmakers often complain about slow regulatory review times, pointing to specific drugs that were approved months, or even years, faster in one market than in others.

The reality is that approval times for new drugs vary from country to country based on the product, regulatory requirements, clock stops, workload and application backlog.

Facing thousands of applications each year for generics, biologics and new drugs, China has an expected standard review time for new drugs of about a year. But because of a backlog of more than 18,000 applications at the beginning of the year, the CFDA's review time is now stretching to an average of 16 months, according to Cortellis Regulatory Intelligence. If the CFDA requests more information, the review could extend an additional six months. (See chart below.)

The stack of drug applications received each year is much smaller in the U.S., where the FDA generally takes 10 months for a standard review and six months for a priority review. The process can be lengthened by multiple clock stops if the agency requests more data. The FDA has no limit for how long it can stop the review clock, unlike China where a clock stop is restricted to six months.

The big outlier in the U.S. is the review time for generics, given a backlog that has grown over a number of years due to staffing issues. Although the FDA receives upward of 1,000 generic applications a year, as compared with about 40 applications for new drugs and biologics, it had no authority to collect user fees for generic drugs until passage of the FDA Safety and Improvement Act (FDASIA) in 2012.

The new generic drug user fees set out in FDASIA enabled the agency to hire more than 900 new staff to work through the backlog and meet a goal of reducing generic approval time to 15 months in 2015 and 2016. The agency intends to reduce generic reviews to 10 months by October 2017, putting them on a par with other drug reviews.

When comparing standard review times across countries, it's important to note the difference between working days and calendar days. While the CFDA's goal is 250 working days, that's actually longer than the 300 calendar days the FDA follows. The CFDA's goal is about the same as Japan's, which has an expected review time of one year for new drugs and biologics.

The Philippines has one of the longest review periods in the world – 600 working days for drugs not approved elsewhere. But most drugs marketed in the Pacific nation have been approved by a regulatory agency with which the Philippines has signed a mutual recognition agreement. Those drugs face a review period of about seven to eight months.

The shortest expected standard review times for new drugs are found in South America – at least on paper. Argentina lists its review time as 69 working days, or about three months, but Cortellis found that the actual time for a new product registration in Argentina is 12 to 24 months.

Brazil also has a three-month goal for reviewing new drugs. In reality, a new product registration generally takes about 16 months there.