Research And Development Of Gastric Retention Preparations Dosage Form Containing Mexican Tea Herbs

Mexican Tea Herb (MTH) belongs to the Chenopodiacea family, which is the main active component of Chinese capsule Jinghuaweikang. MTH can kill Helicobacter pylori (HP) and treat gastric ulcer. Because of the bad water-solubility and oral absorption, the bioavailability of MTH is very low. So we want to prepare a new gastric retention dosage form to prolong the time of MTH in stomach. This new dosage form can increase the treatment concentration in patients'stomach, and can also improve the shortage of commercial capsules.The article is to develop and evaluate gastric retention preparations containing MTH. Making preparations (MTH-GRP) with method of melt pelletization, the formulation was optimized using central composite design-response surface methodology. Independent variables were the weight ratio of Cp and Lactose, the ratio of HPMC and NaHCO3 and the weight of Precirol in adjuvant , while response variables were time of 95% dissolution content, bioadhesion force of melt pellets and floating numbers after 6 hours. Assess the optimum formulation with release behavior in vitro and ability of retention. The optimized formulation was as follows: X1=4;X2=1;X3=0.5, the curve belongs to zero equation and Higuchi equation. The controlled release preparation of MTH can be prolonged for 6 hours, which has the good effective of gastric retention.In order to investigate the stability of MTH-GRP in three months, the content of formulation and determine the drug release in vitro in different conditions were all assayed, which are 25℃±2℃in temperature, 60%±10% in relative humidity and 40℃±2℃in temperature, 75 %±5 % in relative humidity.This article also evaluates the gastric retention ability of MTH-GRP optimum formulation, including determining adhesive force and floating ability in vitro, investigating gastric retention ability of SD mouse in vivo andγ-scintigraphy in rabbits and SD mouse. The results show that the MTH-GRP has good effective of gastric retention.The experiments of kill HP in vitro was used to make sure the MTH-GRP ability of bacteriostasis. Both of the standard strains SSI and ATCC 43504 multiplied slowly or died after giving the drug MTH. We also compared the MIC of MTH and antibiotics in clinic. The MIC of MTH is 0.039mg/mL-0.078mg/mL, which is remarkably lower than other Chinese herb. Rearch of pharmacokinetics shows that the content of MTH-GRP in stomach is much higher than that in plasma. From this result, another conclusion can be obtained, that is the MTH-GRP has a good target of stomach.