Brittain is the second Newmarket trainer to talk about the use of a medication known as Sungate, a joint treatment which contains the banned anabolic steroid stanozolol.
Fellow Newmarket-based trainer Gerard Butler faces charges from the BHA of administering the medication to several of his horses in training and could lose his licence.
Butler said in April - after Godolphin trainer Mahmood Al Zarooni had his licence revoked for eight years for doping racehorses - that Sungate was used at his stables on veterinary advice.
Brittain, who has won many of the world's leading races including the Breeders' Cup, told The Guardian on Monday he expected to avoid punishment from the BHA because the horses in question were out of training at the time.
"They (the BHA) came round and we had a talk," Brittain was quoted as saying on the newspaper website, adding that he had been given no indication if he would face charges but would be "surprised" if he did.
"Any of the horses that were treated by the vets were horses recovering from serious injury," he said. "They weren't in training, they were at rest.
"These horses were months away from a racecourse. It would only have been the horses that had fractures we'd be talking about, six or seven at the most," he added.
He said that the time between each horse being treated and then returning to the racecourse was so great that the effect of any steroid must have worn off.
"When a horse has a fracture, you treat it, you give it time and then you give it more time. It wasn't there to boost their growth," he said.
"We've never had a horse test positive for anything."
Asked if he would have allowed the use of Sungate if he knew it contained an anabolic steroid, he added: "Certainly not, because we've never used anything like that and never would."