Development Of Zhulian Pellets Oral Colon-Specific Capsule Based On Two Step Release And Its In Vitro-in Vivo Evaluations

Ulcerative colitis?UC?is a common autoimmune disease,whose clinical manifestations are mainly digestive symptoms,including abdominal pain,diarrhea,mucus,mucopurulent bloody stool,etc.The course of this disease is protracted and difficult to heal,or even lead to colon cancer in severe cases.At present,the clinical treatment of UC is still dominated by drug methods,while the commonly used chemotherapeutic drugs have some disadvantages that can only alleviate symptoms,and it is difficult to cure and the adverse reactions are obvious,which reduces the patient's compliance.Traditional Chinese medicine has unique advantages in the treatment of chronic gastrointestinal diseases caused by multiple reasons.It also pays attention to the overall balance while symptomatic treatment.Therefore,it is of great potential and practical value to seek and develop new anti-UC drugs from traditional Chinese medicine.Atractylenolide I,the main component of Atractylodes macrocephala volatile oil,can invigorate the spleen,promote the absorption and regulate the movement of the intestinal canal.The alkaloids such as berberine in the ranunculaceae plant Coptis chinensis Franch have the pharmacological activities of clearing away heat and dampness,antibacterial and anti-inflammatory,and can significantly inhibit the symptoms of UC induced by dextran sulfate sodium in mice.The Saposhnikovia divaricata?Trucz.?Schischk mainly contains volatile oil,chromone,coumarin,etc.Its pharmacological activities are mainly concentrated in antipyretic and analgesic,anti-inflammatory,anti-oxidative,immunoregulation and other aspects.For the treatment of UC,there are certain deficiencies in traditional oral and rectal administration.Taking inconvenient,difficult to reach the action site affects the efficacy of the drug.The oral colon-specific drug delivery system has good stability and reproducibility to release the drug at the end of the small intestine and colon,so that the drug can maintain a high drug concentration in the lesion for a long time and improve the drug's bioavailability.In this study,the above-mentioned three traditional Chinese medicines were combined with oral colon-specific drug delivery system,and the research was carried out on the preparation and in vitro-in vivo evaluation of Zhulian pellets,mainly including:the quality control of bulk pharmaceutical chemicals,the prescription composition and preparation process of Zhulian pellets;The establishment of the quantitative method of active ingredients and the investigation of the pharmaceutical properties and stability,as well as the evaluation of in vitro release characteristics and in vivo targeting ability of enteric-coated pellets.To investigate the pharmacokinetic process of the active components in plasma after oral administration;A rat model of UC was established to study the efficacy and mechanism of zhulian pellets against UC.In the first chapter of this study,the determination method of the content of the index components in the three drug substances was established,including the determination of the content of Atractylenolide I in the volatile oil of Atractylodes macrocephala by LC-MS/MS.The HPLC method was used to determine the berberine hydrochloride in the extract of Coptis chinensis Franch and Cimifugin in Saposhnikovia divaricata?Trucz.?Schischk.The system suitability experiments of the three conditions are in line with the standard and can be used for quantitative detection of three components.In the second chapter of this study,the Atractylodes macrocephala volatile oil inclusion compound and the extraction from Coptis chinensis Franch and Saposhnikovia divaricata?Trucz.?Schischk were used as raw materials to prepare the oral colon-specific capsules.The inclusion process and the preparation parameters of extrusion-spheronizatio were optimized by single factor experiment and orthogonal experiment.The formulation of the enteric coating was screened as well.The final prepared gastric and enteric pellets had good roundness and yield.In the third chapter of this study,the content of the index components in gastric and enteric pellets was determined.The macroscopic observation and scanning electron microscopy?SEM?images of the two kinds of pellets showed that the morphology were smooth spherical or ellipsoidal with uniform particle size distribution,indicating that the preparation process of the pellets was reasonable and stable.The two kinds of pellets have stable pharmaceutical properties and nice storage stability,and the content and release characteristics of the active components are less affected by the environment,which is of great significance for future industrial production.The in vitro release evaluation of enteric pellets showed that the pellets had good acid resistance ability.After oral administration,the drug could be released in the intestinal tract to improve drug bioavailability.Its release behavior is more in line with the Higuchi equation release model?r=0.8682?,and the regression equation is Q=34.615 t ^1/2–52.463.The fourth chapter of this study investigated the pharmacokinetics of the Zhulian pellets.The LC-MS/MS content determination method of atractylenolide I and berberine hydrochloride in plasma were established.This method can quantify trace drug in plasma and has good specificity,and is less affected by endogenous substances in plasma.For atractylenolide I,the AUC₀?₃₆ of the pellet group was 1.53 times of the bulk drug group,and the MRT was 1.37 times of the bulk drug group.The blood concentration after the peak was more stable and the bioavailability was significantly improved.The C_max was lower when the berberine hydrochloride was administered with the bulk drug.After the administration of pellets,the T_max was delayed and the C_max and AUC₀?₅₄ were significantly increased.The drug was released in the cecum and colon,so that the lesion region could be maintained high drug concentration,which increases the bioavailability.In the last chapter,the pharmacodynamics of Zhulian pellets was studied.A Dextran Sulfate Sodium?DSS?-induced UC rat model was established to investigate the effects of Zhulian pellets on body weight changes,bloody diarrhea,colonic mucosal injury and histopathological morphology.The expression level of IL-1?,IL-4,IL-6,TNF-?and MPO in serum and tissues was determined by ELISA.The medium and high dose groups of Zhulian pellets can improve the weight loss,reduce the bloody diarrhea rate and various scores in rats,effectively control the damage of colonic mucosal epithelial cells and improve the congestion and swelling of colonic mucosa.Its anti-UC mechanism is mainly resulted in inhibiting inflammatory factors and reduce the production of oxygen free radicals.The in vivo targeting evaluation of enteric pellets show that the pellets can still maintain a high integrity after reaching the colon,which indicates that enteric pellets have good anti-acid ability and colon targeting characteristics,and can release drugs in the gastrointestinal tract after oral administration,thus promoting drug absorption and improving bioavailability.The research of this subject will provide a new effective drug for the clinical treatment of UC,which can enrich the research content of traditional Chinese medicine preparation,and is of great significance for promoting the treatment of UC and the modernization of traditional Chinese medicine.