Enteric capsules
Pharmaceutical capsules exist as “enteric” capsules. It is a well-defined way of making capsules acid resistant. The process is using different polymers such as acrylates, phthalates, or shellac.
Delayed release capsules
Most producers of probiotics (beneficial bacteria) are looking for protection of the microorganisms against stomach acid. The market in Europe for this type of capsules is estimated 300 million pieces a year. The most popular capsule for this is Capsugel DR caps which are only HPMC based.
The exact process how they produce it is not revealed, but they use more of the gelling agents resulting in stronger polymerization of the HPMC.
The new study revealed that the DR capsules begin releasing at about 55 mins when they are about to leave the stomach, so that the contents could often be released in the intestines, where probiotics and enzyme ingredients are most effective.
EEK Acid-resistant capsules
Most “acid-resistant capsules” coming from China are based on a double dip production with HPMC + HPMC phthalate coating. However, the phthalate coating is not allowed in Europe. EEK modified the coating without using HPMC phthalate.
Our acid-resistant capsules can protect ingredients from stomach acids to maintain potency for at least 1 hour, then disintegration and complete release take place within 1 hour in the intestine.
So, EEK acid-resistant capsules displayed delayed release properties like Capsugel DR capsules.