The Pharmaceutical Research Of Floating Pulsatile Tablet Of Apocynum

In this study, the leaves of Apocynum venetum is used as the model drug, to develop a floating pulsatile system, which is based on the principle of both the floating and pulsatile.and used for the treatment of hypertension which is attributed to diseases which have regularity. The delivery system uses the properties that gastric juice is much more than the intestinal fluid to improve the stability of the release time lag and prolong the resident time of preparation in the digestive tract, so that it can keep for a long time in the stomach and gastric with emptying rate can not beaffected,ensuring the release and absorption of drug, by avoiding that the drug had been released when it passed the absorption site, the diseases are easy to attack in the morning, so the patient can take the drug before going to bed,beacause the drug can be released before outbreak of diseases, as a result enhancing the therapeutic effect and medication compliance.The time of hypertension blood pressure peak is around 6-9 o’clock in the morning, thereby cardiovascular accidents almostly occurred in the early morning. Apocynum is mainly used for liver yang dizziness, palpitations, and insomnia,and it is better to treat hypertension,the main components of anti-hypertension are flavonoids,considering the weakness of common dosage forms and the requirement of treatment for hypertension, in this study, Apocynum is prepared as a floating pulsatile tablet,which can be released at a programmed time and site,the research contents are summarized as follows:In extraction technology research, used the hot-dip reflux toextract flavonoids, combining single factor test with central composite design and response surface methodology and taking the total flavonoids as the evaluation index,The optimum extraction process parameters were found as follows:65%ethanol treat as the extraction solvent,extraction time was 150 min, solid-liquid ratio is 1:23, extracted 2 times.In the purification process studying, used the method of static adsorption to screen six different kinds of polarity macroporous resin in the end,the HPD 400 macroporous resin is the best. through the method of dynamic adsorption,considering the adsorption rate and the elution rate of total flavonoids as indexes, the purified optimum conditions and parameters of total flavonoids were investigated by single factor experiment, the final purification process parameters were determined as follows for total flavonoids:the concentration of sample was 0.02g/ml(crude drugs),the flow rate of sample was 1 BV/h, the maximum volume of sample was 4 BV, the volume of water elution volume was 3 BV, the concentration of the elution was the 90% ethanol, the volume of the elution volume was 4 BV, the velocity of the elution wasl BV/h.During the preformulation, finish qualitative and quantitative analysis of the extract of apocynum through methods of thin layer chromatography(TLC) and UV-visible spectrophotometry,by investigatingthe solubility.angle of repose and moisture of the Intermediates, we found that Apocynum extract has better solubility in water, and certain solubility bin acid condition and can meet the sink condition, liquidity was good, critical relative humidity was 77.73%.establishing method for determining the content of apocynum and release rate.In the forming process study, the floating pulsatile tablet consists of three parts:an immediate release tablet core containing drug, a buoyant layer,and time-lagged film coating. Sifting the type and amount of disintegrating agent of immediate release tablet core, the best disintegrating agent is 8%cross-linked povidone (PVPP); adopting mixture design to sift the best ratio of buoyant layer, the best ratio of carbomer (Carbopol) was 30%, hydroxypropyl methylcellulose K4M (HPMC K4M) 36.3% sodium bicarbonate (NaHCO3) was 33.7%; by investigating dissolution and absorbency of the hydrophilic gel excipients, HPMC K4M was approved appropriate. and take lactose as controlled-agents of dissolution rate,by taking single-factor to optimizing the ratio,the best ratio of HPMC K4M and lactose was 4:1 which could make the drug released at a predetermined lag.Preliminary Quality standard research for floating pulsatile tablet, finish qualitative and quantitative analysis of the total flavonoids in floating pulsatile tablet of apocynum through methods of thin layer chromatography(TLC) and UV-visible spectrophotometry.