Screening Of Effective Parts From Sanjiu Weitai And Development Of The Oral In Situ Gels

Gastric ulcer, one of the common peptic ulcer diseases, mainly refers to the mucosal damage caused by gastric digestion. In recent years, the incidence of gastric ulcer has increased due to smoking, irregular diet, work pressure, and mental psychological factors. Ulcer formation is a dynamic imbalance between aggressive mucosal factors and defensive factors. When the defensive factors are less than the aggressive factors, mucosal injuries become worse. Impaired reparative processes of the gastroduodenal mucosa and gastric microvascular abnormalities, impaired bicarbonate and mucus secretion, decreased endogenous prostaglandin synthesis, disintegrity of mucosal layer, gastric mucosal blood flow, and diminished mucosal oxygenation are involved in increased susceptibility to acid and pepsin, which result in gastric ulcer. The treatment of gastric ulcer with traditional Chinese medicine has a long history.Sanjiu Weitai (SJWT), addressed as the king of the Chinese medicine in treatment with gastric ulcer, is a best-selling drug for more than 20 years. It contains eight traditional Chinese medicines including Folium et Ramulus Evodiae, Murrayae Folium et Cacumen, Radix Zanthoxyli, Radix Scutellariae, Radix Paeoniae Alba, Radix Aucklandiae and Poria, Radix Rehmannia. Although SJWT has been used in clinic for many years, its effective parts for anti-gastric ulcer are still unknown. Since the conventional extraction solvent for SJWT is water, we suppose that some liposoluble components have been discarded. This study will investigate the effective parts of SJWT and optimize the extraction process.An in situ gelling system is made of polymer materials that have a solution or semisolid state and responds to external stimuli at the administration site. These gels also have conformations that can undergo reversible conversion to form a semisolid or solid preparation. Compared with conventional dosage forms, an in situ gel is liquid or semisolid in vitro and congeals into gel as orally being administrated, which results in good adhesion and slow release effects. The gel has a three-dimensional network structure that is hydrophilic and has the advantages of good biocompatibility, simple preparation, good mucosal tissue affinity and long residence time.The purpose of this study is to screen the effective parts from SJWT and develope the oral in situ gels. The main research contents include:(1) Screening of the effective parts of SJWT. (2) Feasibility study on purification of SJWT effective parts by macroporous adsorption resin. (3) Optimization of extraction and purification processes of the SJWT effective parts. (4) The preparation of the oral in situ gels for SJWT. (5) Irritation and pharmacodynamics evaluation for the oral in situ gels of SJWT effective parts.1. Screening Effective Parts of SJWTThe anti-gastric ulcer activities of ethanol soluble parts of SJWT were investigated. SJWT was extracted with 95% ethanol and 50% ethanol, and then was extracted with the petroleum ether, ethyl acetate, n-butanol in turn. The SD rats were divided into normal control group, model group, positive control group (cimetidine and SJWT granules), petroleum ether extract group, ethyl acetate extract group, n-butyl alcohol extraction group and water extraction group. Ethanol model of gastric mucosal damage in rats had been adopted with intragastric administration for 7 days. The anti-gastric ulcer activities of different polarity solvent (petroleum ether, ethyl acetate, n-butanol and water extraction) of SJWT alcohol extract were evaluated using gastric ulcer inhibition rate, pepsin activity, serum malondialdehyde (MDA) content and superoxide dismutase (SOD) activity as indexes. According to the results, all the SJWT polar extraction parts had a significant effect on inhibiting ethanol-induced rat gastric mucosa damage. More specifically, the petroleum ether extraction had the best effect on inhibiting the gastric ulcer damage, compared with the cimetidine group and SJWT group. All the polarity extraction parts of SJWT could significantly reduce pepsin activity of rats, enhance the serum SOD activity. The results indicate that different polar extraction parts of SJWT play a significant role in anti gastric ulcer, while the petroleum ether extraction group has highest activity.2. Feasibility study on purification of SJWT effective parts by macroporous adsorption resinIn order to enrichment and purification the effective parts of SJWT, the ethanol extraction was eluted by different concentration ethanol with AB-8 macroporous adsorption resin. Two experiments were designed as follows:(1) to investigate the effect of ethanol lavage gastric ulcer models prevented by SJWT macroporous adsorption resin effective fractions; (2) to investigate the effect of ethanol lavage gastric ulcer models cured by SJWT macroporous adsorption resin effective fractions. The anti-gastric ulcer effect of SJWT macroporous adsorption resin effective parts was evaluated with gastric ulcer inhibition rate, pepsin activity, serum MDA content, SOD activity, NO content, CAT activity and histologic examination as indexes. The results showed as follows:(1) SJWT macroporous adsorption resin effective fractions could significantly prevent or treat gastric mucosa injury of rats caused by ethanol. (2) SJWT macroporous adsorption resin effective fractions could significantly reduce rat pepsin activity and MDA content, strengthen the activity of SOD and CAT and enhance NO content. (3) SJWT macroporous adsorption resin effective parts could not only inhibit the mucosa eroding and bleeding, but also prevent mucosal necrosis and ulceration. The results showed that the SJWT macroporous adsorption resin effective parts had a significant anti-gastric ulcer effect.3. Optimization of extraction and purification processes of SJWT effective partsOptimization of extraction and purification processes of SJWT effective parts were studied by orthogonal test design according to the contents of baicalin, nitidine chloride. The orthogonal tests were disigned as follows:(1) Optimized alcohol extraction process of SJWT effective parts. (2) Optimized the purification process of SJWT effective parts with macroporous adsorption resin. The optimized process as follows:SJWT is extracted with 8 times of 95% ethanol,1.5 h; then it is extracted with 8 times of 50% ethanol,0.5 h once a time,3 times. SJWT macroporous adsorption resin effective parts are purified as follows:(1) solid liquid ratio was 1:20, the concentration of ethanol was 50%, the flow rate was 2 ml·min-1, elution usage was 4 BV. (2) Concentration of ethanol was 80%, the flow rate was 3 ml·min-1, and elution amount was 5 BV.4. The preparation of the oral in situ gels for SJWTTo prepare the oral in situ gelling system of the effective parts, the optimum formulation was screened by the single factor test and multi-factors test successively. The results showed that the best formulation including 400 g effective parts of SJWT, 500 g DGG,100 g CMC-Na,50 g aspartame and the mannitol added to 10000 g. All of the materials are blended with 100 mesh sieve, granulated with 95% ethanol and 16 mesh sieve, dried at 60 ℃, and then pass through the 12 mesh sieve.5. Irritation and pharmacodynamics evaluation for the oral in situ gels of SJWT effective partsThe mucosa irritation of the oral in situ gels was evaluated using rats. The ethanol-induced gastric ulcer rat model was established and the concentration of pepsin, SOD, MDA, NO and CAT were measured as indexes to evaluate the anti-gastric ulcer effects of oral in situ gels of SJWT effective parts. The results indicated that the oral in situ gels of SJWT effective parts showed no obvious mucosa irritation, and had significant attenuate ethanol-induced gastric lesions in rats.In conclusion, in the screening study on the effective parts of SJWT, we firstly find that beside the water soluble component, the liposoluble components also have strong anti-gastric ulcer effect. The extraction and purification processes of the effective parts of SJWT have been designed and optimized in this study. On this basis, the new dosage form for SJWT effective parts, oral in situ gels have been prepared, and the irritation and pharmacodynamics have been evaluated. Above sudies provide the foundation for further development and clinical application of SJWT.