Résumé
Atopic dermatitis (AD) is a chronic, relapsing, inflammatory dermatosis with a variety of clinical manifestations and difficult to cure. Currently, many AD drug candidates have entered the research and development pipeline. In order to provide technical specifications for the clinical development of AD drugs, the Center for Drug Evaluation of National Medical Products Administration released the "Technical Guidelines for Clinical Trials of Drugs for AD Treatment" (Draft for Comments) in November 2022. Non-clinical pharmacodynamics evaluation is an important research before the drug enters clinical trials. Oxazolone (OXA)- and 2,4-dinitro-fluorobenzene (DNFB)-induced models are the most popular classical hapten-induced AD murine models, but variations of modeling are existing in the methods from different studies, including sensitization sites, haptens' dosages, the period of challenges, and the skin lesions severity evaluation as well. In this study, the investigation of OXA- and DNFB-induced AD murine models with various conditions of modeling was performed to compare the characteristics of hapten-induced AD murine models in the pathological process and severity according to the appearance of AD patients, and the guidance of pharmacodynamics evaluation of AD-therapeutic drugs in clinical trials as well, which may provide a proposal for AD treatment drug candidates in the non-clinical pharmacodynamics evaluation. All animal experiments were approved by the Animal Care & Welfare Committee of Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College (approval No.: 00007782 and 00007784).
Résumé
Abstract; Aim To explore the differences of 2,4-dinitrofluoro- benzene ( DNFB) -induced allergic contact demiatitis (ACD) models with different modeling cycles for the study of skin itch¬ing and inflammation, so as to provide reference and basis for the identification and selection of a more suitable animal model.Methods DNFB was used as a sensitizer, 0.5% DNFB was used to build a 2-week ACD model, and after 5-day sensitiza¬tion, the modeling site was administered once every other day and repeated four times.0.15% DNFB was used to build a 5- week ACD model, and after one week of treatment, DNFB was applied to the modeling site twice a week for four weeks.Behav¬ioral videos were recorded for 60 minutes alter each application of DNFB on the back of the neck for 24 hours.After modeling, Ig-K levels in serum were detected by KLISA, and the skin at the modeling site was stained for histopathology and observed.Results The entire modeling process of both modeled ACD mice was accompanied by severe scratching response after re¬peated skin exposure to DNFB, and the number of scratching significantly increased (P <0.01).Histopathological results showed epidermal thickening ( P < 0.01 ) , hyperkeratosis and inflammatory cell infiltration (P <0.01) in both modeling meth¬ods, and senmi Ig-F levels were significantly elevated ( P < 0.01).Conclusions The contact dennatitis model caused by DNFB is very stable, showing typical pruritus symptoms, severe dermatitis injury and inflammatory immune response, but the 5- week model may have more typical symptoms and allow enough time to observe the effect of the drug, which provides further ex¬perimental basis and evidence for pruritus and inflammation re¬lated drug research.
Résumé
OBJECTIVE:To establish derivative spectrophotometry for the determination of the main component of Captopril tablets.METHODS:Under the alkaline condition of sodium hydroxide,2,4-dinitrofluorobenzene was used as derivatization reagent to react with captopril at 40 ℃ in the water bath.Then UV spectrophotometry was adopted to detect the content of captopril with detection wavelength set at 342 nm.RESULTS:The linear range of captopril was 1.0～14.0 ?g?mL-1(r=0.999 9) with an average recovery of 99.61%(RSD=1.27%,n=9).The RSD of intra-day and inter-day both were less than 2%.CONCLUSION:This method is stable,reliable,rapid and simple for the determination of the main components of Captopril tablets.
Résumé
OBJECTIVE:To establish a RP-HPLC precolumn derivatization method for the content determination of argi-nine(Arg)and proline(Pro)in Folium Isatidis.METHOD:2,4-dinitro-fluorobenzene was undergone precolumn derivatization and the amino acids was determined directly under alkaline condition with Kromasil C 18 as chromatographic column,the mobile phase was composed of sodium acetate buffer solution(pH=6.4)-acetonitrile(850∶150)with detection wavelength at360nm,the content was calculated by external reference method.RESULTS:The linear ranges for Arg and Pro were0.627?g～5.016?g(r=0.9996)and0.874?g～7.000?g(r=0.9995),respectively.The average recovery was98.2%with RSD at2.3%and2.2%,respectively.CONCLUSION:The method is simple,accurate and reliable,and suitable for the assaying of amino acids in Folium Isatidis.