SINGAPORE - A 58-year-old pharmacist who unlawfully sold codeine-based cough syrup for about a decade was on Wednesday (Dec 7) jailed for eight months and three weeks.

William Woo Tat Meng, who is the sole proprietor of Community Pharmacy at Bukit Timah Plaza, is the first pharmacist to be found guilty of the crime under the Poisons Act.

He sold an estimated 20,440 bottles containing 2,452.8 litres of Dhasedyl syrup to customers without recording their particulars between May 7, 2013, and April 23, 2015.

He made a profit in the range of $244,529 to $285,409 from the improper sales of the 120ml bottles.

Woo also falsified his company records to cover his tracks.

He had earlier pleaded guilty to three out of four charges, including two for providing false information to a Health Sciences Authority (HSA) officer.

A district court heard that HSA started probing Community Pharmacy on March 26, 2015, upon realising that the pharmacy had been ordering large quantities of Dhasedyl syrup between May 7, 2013, and April 23, 2015.

On April 10, 2015, when HSA carried out an audit at the pharmacy, Woo gave a dispensing ledger dated "Feb 2015 to April 2015", which had been falsified. The records wrongly showed that he did not prescribe more than 240ml of cough mixture containing codeine to each customer on each occasion.

During the audit, a HSA officer spotted six cartons of Dhasedyl Syrup in Woo's office. He lied that he had ordered more of the medicine because his supplier was increasing his price.

At about 3pm on April 23, 2015, HSA officers stopped a 42-year-old Malaysian man who had just left Community Pharmacy. The officers had been conducting surveillance on the pharmacy.

The man, Mohamad Othman, had 14 bottles, each containing 120ml of Dhasedyl syrup inside his backpack. He paid $20 for each bottle, and Woo did not ask for his particulars.

Mohamad said he had been buying cough syrup from Community Pharmacy since 2000, when he started working in Singapore. He found out through friends that he could buy it easily there. Each bottle of Dhasedyl syrup cost $18, but if more than six bottles were bought, it would cost $20 per bottle.

At about 5.30pm on April 23, 2015, HSA officers asked Woo for records of Community Pharmacy's latest sales of codeine-based cough mixture.

He gave them a book titled "April 2015" but, while officers were looking through it, Woo admitted that he had entered 14 fictitious names for the sale of 14 bottles to Mohamad.

Woo also said he updated his dispensing ledger by making fictitious entries of a person's particulars or by re-entering previous customers' details.

He admitted that he had been selling Dhasedyl syrup for about 10 years.

Under the Poisons Act, pharmacists are not allowed to sell more than 240ml of codeine cough preparation to a customer on each occasion.

Pharmacists who sell codeine cough syrup have to record the name and identity card number of the customer and the quantity of codeine cough syrup sold on a daily basis in a book kept exclusively for this purpose.

The worst reported case of unauthorised sale of codeine was that involving a pharmaceutical company sales manager who supplied more than 20,000 litres of codeine-based cough syrup and codeine tablets to a Malaysian man. Ashley Jas Ang Wei Hoon, 38, was jailed for 20 months in November 2015 after she pleaded guilty to 60 out of 395 charges, including for forgery.