There is no suggestion that the company has misled the businesses that sponsor its booklets, and trading standards officers have not received any complaints.
Neither is there any suggestion that the information in its leaflets is inaccurate or out of date.
Sponsor businesses are asked to pay pound;159 for 32 books, or pound;300 for 70.
Ms Rainnie said her books had benefited hundreds of schools.
"They have true stories in them so children get a clear message about the dangers," she said. "We get phone calls from schools every day asking for more copies.
"Businesses support us because they believe in it, not because they are forced to."
Ms Rainnie said that, although the company was run for profit, it made regular donations to children's charities, but declined to give details.
She said it was planning to open an office in America in the next eight weeks "DrugScope are very good at what they do, but they need to broaden their horizons," she said. "We need to work together."
Glossopdale community college in Derbyshire has received six sets of Child Protection UK booklets over the past two years, sponsored by different businesses.
Andrew Bruce, assistant principal, said: "We found them to be useful, and the teachers did not have any particular concerns about their content. We didn't question it too much."