AOAC 15.1.04 AOAC Official Method 998.10 Efficacy of Preservation-国外标准规范

15.1.04

AOAC Official Method998.10

Efficacy of Preservation

of Non-Eye Area Water-Miscible Cosmetic

and Toiletry Formulations

First Action1998

Caution:A knowledge of microbiological techniques is required for these procedures.Follow general aseptic and safety

procedures(1).

See Table998.10for the results of the interlaboratory study sup-porting the acceptance of the method.

A.Principle

Bacteria,yeast,and mold are grown on laboratory media,har-vested,calibrated,and inoculated into test ing serial di-lutions and plate counts,the numbers of organisms surviving in the test products are determined over time.Products meeting the speci-fied criteria are considered adequately preserved for manufacture and consumer use.Products not meeting criteria are considered in-adequately preserved.

B.Apparatus

(a)Jars.—2–4oz.wide-mouth,straight-side flint glass ointment jars with linerless metal,polypropylene or Teflon®lined screw caps.

(b)Disposable borosilicate glass culture tubes.—16×125mm, with caps.

(c)Disposable borosilicate glass culture tubes.—20×150mm, with screw caps.

(d)Petri plates.—100×15mm.

(e)Sterile2.2mL pipets.

(f)Sterile swabs.

(g)Glass beads.

(h)Sterile gauze.

(i)10–20µL inoculating loops.

(j)Vortex mixer.

C.Reagents

For convenience,dehydrated media of any brand equivalent in function may be used.Test each lot of medium for sterility and growth-promotion using suitable organisms.

(a)Letheen agar.—Contains5.0g pancreatic digest of casein,

1.0g dextrose,3.0g beef extract,1.0g lecithin,7.0g polysorbate80, and15.0g agar per L.Prepare according to manufacturer’s directions. Dispense into suitable containers and sterilize by autoclaving at 121E C for15min.Final pH should be7.0±0.2at25E C.Place in45E C water bath until agar is45±2E e for pour plates.

(b)D/E neutralizing broth(Dey/Engley).—Contains5.0g pan-creatic digest of casein,2.5g yeast extract,10g dextrose,1.0g so-dium thioglycollate,6.0g Na2S2O3⋅5H2O,2.5g NaHSO3,7.0g lecithin,5.0g polysorbate80,and0.02g bromcresol purple per L. Prepare according to manufacturer’s directions.Dispense9or 9.9mL aliquot into tubes and sterilize by autoclaving at121E C for 15min.Final pH should be7.6±0.2at25E e for aerobic plate count,L,dilutions.

(c)Nutrient agar.—Contains5.0g pancreatic digest of gelatin,

3.0g beef extract,and15.0g agar per L.Prepare according to manu-facturer’s directions.Dispense into tubes and sterilize by autoclaving at121E C for15min.Final pH should be6.8±0.2at 25E C.Cool in inclined position to form a e for bacterial cul-ture maintenance and inoculum preparation.

(d)Y/M agar(yeast/malt extract).—Contains3.0g yeast extract,

3.0g malt extract,5.0g peptone,10.0g dextrose,and20.0g agar per L.Prepare according to manufacturer’s directions.Dispense into tubes and sterilize by autoclaving at121E C for15min.Final pH should be6.2±0.2at25E C.Cool in slanted e for yeast culture maintenance and inoculum preparation.

(e)Potato dextrose agar(PDA).—Contains200g potato infu-sion,20.0g dextrose,and15.0g agar per L.Prepare according to manufacturer’s directions.Dispense into tubes and sterilize by autoclaving at121E C for15min.Final pH should be5.6±0.2at 25E C.Cool in slanted e for mold culture maintenance and inoculum preparation.

(f)0.85%Saline.—Dissolve8.50g NaCl in water and dilute to 1L.Dispense into flasks or bottles and sterilize by autoclaving at 121E C for15min.

(g)0.85%Saline with0.05%polysorbate80.—Dissolve8.5g NaCl in water,mix in0.50g polysorbate80,and dilute to1L.Dis-pense into suitable containers and sterilize by autoclaving at121E C for15min.

(h)Barium sulfate standard No.2.—(1)Prepare a1.0% BaCl2solution by dissolving1.0g BaCl2⋅2H2O in100mL water.

(2)Prepare a1.0%H2SO4solution by mixing1.0mL H2SO4in 100mL water.(3)Mix0.2mL solution,(1),with9.8mL solu-tion,(2),in a screw-capped test tube.Cap tightly and store in dark at room temperature.

(i)Barium sulfate standard No.7.—Use solutions from C(h).Mix

0.7mL solution,(h)(1),with9.3mL solution,(h)(2),in a screw-capped test tube.Cap tightly and store in dark at room temperature.

D.Microorganisms

(a)Staphylococcus aureus.—ATCC6538.

(b)Staphylococcus epidermidis.—ATCC12228.

(c)Klebsiella pneumoniae.—ATCC10031.

(d)Escherichia coli.—ATCC8739.

(e)Enterobacter gergoviae.—ATCC33028.

(f)Pseudomonas aeruginosa.—ATCC9027.

(g)Burkholderia cepacia.—ATCC25416.

(h)Acinetobacter baumannii.—ATCC19606.

(i)Candida albicans.—ATCC10231.

(j)Aspergillus niger.—ATCC16404.

(Note:Environmental microorganism(s)likely to be contami-nants of concern during product manufacture or use are included as a separate inoculum.Predominant environmental microbes isolated during manufacturing,equipment cleaning,and sanitizing,or from related deionized water systems are used as supplemental test inocula.)

For culture revival and maintenance,consult references1and2.

E.Product Quality Check

(a)Weigh1.0g product into a screw-capped culture tube con-taining9.0mL sterile neutralizing broth to make a1:10dilution.If necessary to disperse product,add10to twenty3mm diameter glass beads to tube.Mix on Vortex mixer until homogeneous.

(b)Pipet1.0mL of the1:10dilution into each of4sterile Petri plates.Pour15–20mL sterile molten Letheen agar(45±2E C)into each plate.Mix by rotating plates to disperse the dilution thoroughly. Let solidify.