The US Food and Drug Administration (FDA) made the recommendations in guidance last week in which it said new generic pills and capsules should be a similar shape and size to originator products.
The Agency said: “We are concerned that differences in 24 physical characteristics may affect patient compliance and acceptability of medication regimens or could lead to medication errors.”
It suggested that a reference drug's size, weight and film coating be considered during development of quality target product profiles (QTPPs) for new generic medicines.
"Size and shape of tablets and capsules affect the transit of the product through the pharynx and esophagus and may directly affect a patient’s ability to swallow a particular drug product. Larger tablets and capsules have been shown to have a prolonged esophageal transit time."
The agency also said generic pharmaceutical products should also be of "a similar shape" to the reference drug.
Specific recommendations include that generics are no more than 20% larger and 40% bigger by volume than originators if the branded drug is less than 17mm it its largest dimension.
Some flexibility is permitted when the reference product is less than 8mm in diameter.
For larger branded pills and capsules, the FDA suggests that any generic versions should be the same size and volume or smaller.
While the recommendations only apply to new generics, the FDA said it will notify abbreviated new drug application (ANDA) holders if it think the shape of an approved non-branded pill or capsule poses a risk to public health.
Dosage form contractor Hermes Pharma welcomed the FDA's efforts to improve patient safety and compliance but voiced concerns about its approach.
Thomas Hein, Senior Vice President Commercial and Regulatory Affairs, told us: "We applaud the FDA for bringing to light the problem that many patients experience when swallowing tablets or capsules but believe that rather than adjusting the tablets and capsules, the industry would better serve patients by providing them with existing, alternative dosage forms.
He added that: "The FDA suggests that difficulty swallowing tablets and capsules can be tackled through limiting size differences between therapeutically equivalent tablets, manufacturing generic tablets and capsules that have a similar shape to the reference listed drug (RLD) or considering other physical attributes such as coating, disintegration time and propensity for swelling. While these points from the FDA are valid and helpful considerations for the industry, alone they are insufficient to solve this problem.
"These recommendations fail to tackle the problem directly as patients are still having to deal with solid oral dosage forms that are negatively impacting their compliance and health" Hein said.