The research, commissioned by solid dosage formulation specialist Colorcon, compared the "swallowability" of several forms of tablets, including uncoated tablets and caplets, soft and hard gelatine capsules, and film-coated capsules.
Researchers at Bio-Images Research, the Glasgow-based firm who conducted the study, used nuclear medicine cameras to analyse medication passage from the mouth to the lower gastro-intestinal tract of 48 patients, and found that oval film-coated tablets demonstrated the fewest instances of slow transit - exceeding 15 seconds - in the oesophagus.
Furthermore, the study showed that this type of tablets was the least likely to cause swallowing problems and that it led to fewer incidences of lodging in the oesophagus.
Forty per cent of people report problems swallowing pills, according to recent research and analysts estimate that 60 per cent of older people have trouble swallowing medication.
What is more, according to the National Institutes of Health, between one and four million Americans - of which 90 per cent are women - suffer from Sjogren's Syndrome, which makes swallowing solid dosage forms particularly difficult.
It is therefore in drug makers' interest to come up with innovative solutions for solid dosage forms in order to make their products more patient-friendly.
Colorcon spotted the opportunity and recently came up with its Brand Enhancement System for Tablets (BEST), a consulting and design service for solid dosage products that helps pharmaceutical companies to distinguish their tablets through colour, shape, high-definition imprinting, special coatings, flavours, and product security identifiers.
"The study has important implications for both pharmaceutical manufacturers and patients, especially those who have swallowing difficulty," said Frederick Kettinger, general manager of Brand Enhancement Services at Colorcon .
"The results confirm that film-coating an oval-shaped dosage form improves the ease of swallowing for patients, enabling the dosage to safely and quickly pass through the oesophagus, without concern about lodging and mucosal irritation."
In addition, coated oval tablets appear to provide greater comfort for patients, as well as acceptance and safety, and could also lead to improved compliance, said Kettinger.
These findings could boost the pharmaceutical film-coating market estimated to be worth about €200m in 2004 and growing at five to six per cent a year.