The agency's annual accounts for the year ended 31 December 2009 state that turnover grew from £25.3m in 2008 to £31.1m in 2009.
It attributes the growth to "increasing business from existing clients and several new client wins during the year".
It also reported pre tax profit of £1.2m, down from £1.3m in 2008. However, gross profit was up from £5.1m in 2008 to £5.5m in 2009.
"We are optimistic that the company can continue to grow in line with our strategic plans for global development as we look to 2012 and beyond," the report said. "We remain, however, cautious about the potential impact of the current economic climate on our business in the short term."
Chief executive Martin Parry said: "We are delighted with these numbers which demonstrate our ability to deliver increasing profits even in challenging economic and market conditions. Our strategy of focusing on the pharmaceutical sector has proven to be a sound one."