Packaging and storage— Preserve in tight containers.

USP Reference standards á11ñ— USP Lidocaine RS.

Identification— Place in a separator containing 10to 15mLof water a quantity of Jelly,equivalent to about 300mg of lidocaine hydrochloride,mix to assure thorough dilution of the Jelly,add 4mLof 6Nammonium hydroxide,and extract with four 15-mLportions of chloroform.Combine the chloroform extracts,and evaporate with the aid of a current of warm air to dryness.Redissolve the crystals in solvent hexane,evaporate with the aid of warm air,and dry the residue in vacuum over silica gel for 24hours:the lidocaine so obtained responds to Identificationtest Aunder Lidocaine.

Sterility á71ñ: meets the requirements.

Minimum fill á755ñ: meets the requirements.

pHá791ñ: between 6.0and 7.0.

Assay— Accurately weigh into a separator containing 10to 15mLof water a quantity of Jelly,equivalent to 20to 30mg of lidocaine hydrochloride,mix to assure thorough dilution of the Jelly,add 1mLof 6Nammonium hydroxide,and extract by shaking with four 20-mLportions of chloroform.Combine the chloroform extracts,and evaporate with the aid of a current of warm air,adding 25.0mLof 0.01Nsulfuric acid VSjust before the last trace of chloroform is expelled.Complete the evaporation of the chloroform,and titrate the excess acid with 0.01Nsodium hydroxide VS,determining the endpoint potentiometrically (see Residual Titrationsunder Titrimetry á541ñ).Each mLof 0.01Nsulfuric acid is equivalent to 2.708mg of C14H22N2O·HCl.

Expert Committee:(PA1)Pharmaceutical Analysis 1

USP28–NF23Page 1131

Phone Number:1-301-816-8379