Wuxi Zhengda - Enteric dissolving determination of four kitasamycin product

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Enteric dissolving determination of four kitasamycin product

Theoretically, we hope that Kitasamycin can 100% pass the stomach and 100% dissolved in small intestine.But it is impossible in reality. Even use the best coating material acrylic resin (which is normal enteric-coating material of medicine of human beings) can not realize.
Below we will show you the method to decide if the kitasamycin is enteric-dissolving or not, and an experiment to determine the pecentage of kitasamycin dissolved in stomach and small intestine.

1 Normal method to decide if the kitasamycin product is enteric-dissolving or not

Put the kitasamycin into the simulating gastric solution (hydrochloric acid solution, pH3.0). If the product is disintegrated in 2hours, means it’s not intestinal dissolving product; if not, do the next experiment.
Puts kitasamycin into simulating intestine solution (phosphate buffer solutiontakes PH 6.8. compound method: take 0.2ml/L potassium dihydrogen phosphate solution 250ml, adds 0.2ml/L caustic soda solution 118ml, and dilutes to 1000ml.). Intestinal coated kitasamycin should to break up gradually; and the longest disintegration time should less than 4 hours. The product that totally dissolved in half an hour is not enteric-coated product. And the product that can not totally disolved in 6 hours also not enteric-coated product (means use non-enteric-dissolving coating materal, kitasamycin can not totally dissolved out in small intestine).

For example: enteric-coated kitasamycin VS kitasamycin raw powder

2 Laboratory method of determination kitasamycin enteric-dissolving

1 material and method

1.1 Material

Spectrophotometer; Medicine dessolving determenation apparatus.
4 kitasamycin 50% product No 1, No 2, No 3 and No 4 (all labeled enteric dissolving), Thereinto include 1 product made by Wuxi Zhengda.
Hydrochloric acid solution (HCL, PH3.0) and phosphate buffer solution (PH6.8)

1.2 Method

4 beakers each filled 900 ml simulating gastric solution. Take these beakers in the medicine dessolving determenation apparatus. Heat to 37.5℃ and keep the same temperature. Take the 4 kitasamycin product into the four beakers respectively, machine outomatically stir and begin to time. 2 hours later, use filtration membrane (diameter 0.6μm) to filter, use spectrophotometer to determine the kitasamycin content in the filter liquor. And take the oversize product into another 4 beaker filled 900 ml simulating intestine solution (37.5℃), stir and begin to time. Every 2 hours take the liquor and determine the kitasamycin content, last for 8 hours.

2 Results

Dissolving percentage of 4 kitasamycin product in simulating gastric solution and simulating intestine solution (%)

Item	Time	No 1	No 2	No 3	No 4
Simulating gastric solution	2h	32.3	37.4	76.9	29.2
Simulating intestine solution	2h	47.3	53.2	2.6	29.4
	4h	54.7	56.1	15.5	37.6
	6h	68.5	67.1	31.2	42.1
	8h	68.2	66.7	33.4	41.2

In simulating gastric solution: product No 1,2 and 4 dissolved in the simulating gastric solution is 32.3%, 37.4 and 29.2%, while the No 3 is 76.9%. That means all product can not avoid gastric dissolving. And the No 3 product is the worst, because most kitasamycin were dissolved into the stomach.
In simulating intestine solution: 6 hours later, the rest kitasamycin of No1 and No2 all dissolved (68.5+32.3≈100.8; 67.1+37.4=104.5, the total is not 100 because of detemination errors), but No 4 just resolved 42.1%, totally dissolved 70.4% in simulating gastric solution and simulating intestine solution.
We can draw a conclusion: in the four products, product No1 is the best, the second is No2. Acually product No1 represents the top eneric-coated technology of Kitasamycin. No 2 is also a qualified product; No 3 is not a enteric product, just normal granule; No 4 is not qualified product because it can not totally dissolved in simulating intestine solution, its coating material is not enteric-dissolved.