Study On The Quality Of TTX And The Preparation Process Of TTX Soft Capsule

Tetrodotoxin(TTX),one of the most toxic non-protein neurotoxin,is a highly toxic alkaloid.Although TTX is highly toxic,its highly active and specific biological characteristics have potential and huge pharmaceutical development value.TTX which has broad prospects for clinical applications is still widely used as a tool for physiology and pharmacology researchs.As a kind of typical sodium channel blockers,TTX can binding to sodium channels receptors selectively,and can hinder the voltage-dependent sodium channels,then block action potentials and hinder excitement generated of nerve muscle.In this article the quality standard of TTX was established,single-factor was studied to optimize the formulation and technology,and the analgesic effect of TTX Soft Capsule was evaluated by the acid-induced writhing test and the hot-plate test in mice.1.Study on the quality standard of TTXThe main contents include characters,melting point,solubility,identification,its related substances and assay.The HPLC method for the determination of TTX and its related substances was established.HPLC was carried out on a Phecda Diol column(4.6 mm×250 mm,5 ?m)with acetonitrile-0.3%formic acid and 10 mmol of ammonium formate(83:17)(v/v)as the mobile phase at a flow rate of 1.0 mL·min-1.The detection wavelength was 196 nm,and the column temperature was maintained at 30 ?.It was show that the established content method had good linearity and precision within the range of 60?140 ?g/mL(r=0.9999).The limit of detection(LOD)was 10 ng(S/N=3).This method is simple,feasible and reproducible.The quality of TTX can be controlled by the method.Furthermore the stability of TTX was studied,and the results showed that the quality of TTX is stable.2.Study on formulation optimization and preparation process of TTX Soft CapsuleThe formulation and preparation process of TTX Soft Capsule were optimized by single-factor tests and analgesic experiments.Scale-up test was carried out for TTX Soft Capsule.The results showed that the best solubilizer was the mixture of 50%P40 and 50%GML,and the antioxidant was Vitamin E.The stirring time was 20 minutes,the stirring temperature was 60 ?.The content of TTX Soft Capsule induced significant increases of the enhancement rate of pain threshold and inhibition rate of writhing response.The lowest effective dose is 0.5 ?g/kg.The proportion of gelatin,glycerol and water was 1.0:0.3:1.0.Three batch of the samples are consistent with the quality standards of 2010 version of China Parmacopoeia.