Hip
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Using Shellac Confectioners Glaze to Make Enteric-Coated Probiotics
When taking oral probiotics, only about 20% to 40% of the friendly bacteria in the capsule survive the transit through the stomach acid and bile, and make it alive to the colon. Ref: 1 So many of the bacteria are lost.
So solve this problem, a small number probiotic manufacturers place an enteric coating on their probiotic capsules to protect the bacteria in the capsule from stomach acids; but enteric-coated probiotics are not common.
However, you can easily make your own enteric-coated capsules at home by dipping the capsules into confectioners glaze, a shellac-based liquid product used in the kitchen to place a shiny edible glaze on chocolates and cakes.
There are many confectionary glaze products on the UK Amazon.
The product I bought is this one. These confectioners glaze products are more difficult to find in the US, but they are available.
The Shellac Coating Technique
When coating my capsules, I use a shellac solution in a bottle (rather than the shellac aerosol sprays you can buy). This liquid solution is shellac dissolved in alcohol (ethanol). Shellac is a natural resin, and as well as being used to glaze confectionary, is also used as a enteric coating for pharmaceutical drugs.
To coat your capsules, you can pour around 20 or 30 ml of the shellac solution into a small cup, and dip in your capsules into this liquid, using a tweezers or similar to push the capsules beneath the liquid surface, so that the whole of the capsule is fully coated with shellac.
After a quick dip, you then place the wet capsules on a non-porous surface (such as a plastic food bag) to dry for several hours (takes about 6 hours or so to dry). Once dry, these capsules will have an acid-resistant enteric coating, and can be placed back in their jar.
Note that these capsules may stick to the non-porous surface, and when you pull them off, it may remove an area of the shellac coating from the capsule. So then you may need to patch up and repair that area with some more shellac. I use a Q-tip to paint on a bit more shellac onto the area of the capsule that needs patching up.
Shellac is water-resistant and acid-resistant, but is eventually is broken down, so the capsule should open and release its contents in the digestive tract beyond the stomach.
Demonstration of Acid-Resistance of the Shellac Coating
I experimented to see if 3 coatings of shellac on a capsule might be better than just one.
It turns out that just one coating is perfectly good, and this single coating prevented my capsules from opening and spilling their contents when placed in vinegar for 4 hours. That is more than enough time, since food transit from the stomach to the intestines usually occurs within 2 hours.
The pictures below show four different capsules of vitamin B2 placed in four little plastic pots containing white vinegar. The capsule in the first jar on the left has no coating at all, and you can see that this uncoated capsule dissolved quickly in the vinegar within 30 minutes.
The other three capsules have 1, 2 and 3 coatings of shellac. You can see that at the 2 hour stage, all of these shellac coated capsules remained intact in the vinegar, and had not spilled their contents.
At the 4 hour stage, most capsules still remained intact, but ironically it was the capsule on the right which had 3 coatings that started to spill its contents at 4 hours.
Some Uncoated and Shellac Coated Vitamin B2 Capsules Dropped into Vinegar
When taking oral probiotics, only about 20% to 40% of the friendly bacteria in the capsule survive the transit through the stomach acid and bile, and make it alive to the colon. Ref: 1 So many of the bacteria are lost.
So solve this problem, a small number probiotic manufacturers place an enteric coating on their probiotic capsules to protect the bacteria in the capsule from stomach acids; but enteric-coated probiotics are not common.
However, you can easily make your own enteric-coated capsules at home by dipping the capsules into confectioners glaze, a shellac-based liquid product used in the kitchen to place a shiny edible glaze on chocolates and cakes.
There are many confectionary glaze products on the UK Amazon.
The product I bought is this one. These confectioners glaze products are more difficult to find in the US, but they are available.
The Shellac Coating Technique
When coating my capsules, I use a shellac solution in a bottle (rather than the shellac aerosol sprays you can buy). This liquid solution is shellac dissolved in alcohol (ethanol). Shellac is a natural resin, and as well as being used to glaze confectionary, is also used as a enteric coating for pharmaceutical drugs.
To coat your capsules, you can pour around 20 or 30 ml of the shellac solution into a small cup, and dip in your capsules into this liquid, using a tweezers or similar to push the capsules beneath the liquid surface, so that the whole of the capsule is fully coated with shellac.
After a quick dip, you then place the wet capsules on a non-porous surface (such as a plastic food bag) to dry for several hours (takes about 6 hours or so to dry). Once dry, these capsules will have an acid-resistant enteric coating, and can be placed back in their jar.
Note that these capsules may stick to the non-porous surface, and when you pull them off, it may remove an area of the shellac coating from the capsule. So then you may need to patch up and repair that area with some more shellac. I use a Q-tip to paint on a bit more shellac onto the area of the capsule that needs patching up.
Shellac is water-resistant and acid-resistant, but is eventually is broken down, so the capsule should open and release its contents in the digestive tract beyond the stomach.
Demonstration of Acid-Resistance of the Shellac Coating
I experimented to see if 3 coatings of shellac on a capsule might be better than just one.
It turns out that just one coating is perfectly good, and this single coating prevented my capsules from opening and spilling their contents when placed in vinegar for 4 hours. That is more than enough time, since food transit from the stomach to the intestines usually occurs within 2 hours.
The pictures below show four different capsules of vitamin B2 placed in four little plastic pots containing white vinegar. The capsule in the first jar on the left has no coating at all, and you can see that this uncoated capsule dissolved quickly in the vinegar within 30 minutes.
The other three capsules have 1, 2 and 3 coatings of shellac. You can see that at the 2 hour stage, all of these shellac coated capsules remained intact in the vinegar, and had not spilled their contents.
At the 4 hour stage, most capsules still remained intact, but ironically it was the capsule on the right which had 3 coatings that started to spill its contents at 4 hours.
Some Uncoated and Shellac Coated Vitamin B2 Capsules Dropped into Vinegar
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