Test Methods for Plastic Containers may be used for designing and quality assurance of plastic contain-ers. Not all tests described here will be necessary in any phases for any containers. On the other hand, the set does not include sufficient number and kinds of tests needed for any design verification and quality assurance of any containers. Additional tests may be considered, if necessary.
Combustion Tests
(1) Residue on ignition Weigh accurately about 5 g of cut pieces of the container and perform the test according to the Residue on Ignition.
(2) Heavy metals Place an appropriate amount of cut pieces of the container in a porcelain crucible, and perform the test according to Method 2 of the Heavy Metals Limit Test. Prepare the control solution with 2.0 mL of standard lead solution.
(3) Lead
Method 1: Place 2.0 g of cut pieces of a container in a crucible of platinum or quartz, moisten with 2 mL of sulfuric acid, heat slowly to dryness, then heat to combustion at between 450 °C and 500 °C. Repeat this procedure, if necessary. After cooling, moisten the residue with water, add 2 to 4 mL of hydrochloric acid,
evaporate to dryness on a waterbath, then add 1 to 5 mL of hydrochloric acid, and warm to dissolve. Then add 0.5 to 1 mL of a mixture of a solution of citric acid (1 in 2) and hydrochloric acid (1 : 1), and add 0.5 to 1mL of a warmed solution of ammonium acetate (2 in 5). Filter through a glass filter, if insoluble matter re-mains. To the obtained filtrate, add 10mL of diammonium hydrogen citrate solution (1 in 4), 2 drops of bromothymol blue TS and ammonia TS until the color of the solution changes from yellow to green.
Then add 10 mL of a solution of ammonium sulfate (2 in 5) and water to make 100 mL. Add 20 mL of a solu-tion of sodium diethyldithiocarbamate (1 in 20) to this solution, mix, allow to stand for a few minutes, then add 20.0mL of 4-methyl-2-pentanone, and shake vig-orously. Allow to stand to separate the 4-methyl-2-pentanone layer, filter, if necessary, and use the layer as the test solution. Separately, to 2.0 mL of standard lead solution, add water to make exactly 10 mL. To 1.0mL of this solution, add 10mL of diammonium hy-drogen citrate solution (1 in 4) and 2 drops of bromothymol blue TS, then proceed in the same man-ner as for the test solution, and use the solution so ob-tained as the standard solution. Perform the test with the test solution and the standard solution according to Atomic Absorption Spectrophotometry under the fol-lowing conditions, and determine the concentration of lead in the test solution
Gas: Dissolved Acetylene or hydrogen—Air.
Lamp: Lead hollow cathode lamp.
Wavelength: 283.3 nm.
Method 2: Cut a container into pieces smaller than 5-mm square, take 2.0 g of the pieces into a glass beaker, add 50 mL of 2-butanone and 0.1mL of nitric acid, and warm to dissolve. To this solution, add 96 mL of methanol gradually to precipitate a resinous substance, and filter by suction. Wash the beaker and the resinous substance with 12 mL of methanol fol-lowed by 12 mL of water, combine the washings and the filtrate, and concentrate to about 10 mL under re-duced pressure. Transfer into a separator, add 10 mL of ethyl acetate and 10 mL of water, shake vigorously, and allow to stand to separate the water layer. Evapo-rate the water layer to dryness, add 5mL of hydrochlo-ric acid to the residue, and warm to dissolve. Then add 1mL of a mixture of a solution of citric acid (1 in 2) and hydrochloric acid (1:1), and add 1mL of a warmed solution of ammonium acetate (2 in 5). Filter through a glass filter (G3), if insoluble matter remains. To the solution so obtained, add 10mL of a solution of diammonium hydrogen citrate (1 in 4) and 2 drops of bromothymol blue TS, and then add ammonia TS until the color of the solution changes from yellow to green.
Further add 10mL of a solution of ammonium sulfate (2 in 5) and water to make 100 mL. Add 20 mL of a solution of sodium diethyldithiocarbamate (1 in 20) to this solution, mix, allow to stand for a few minutes, then add 20.0 mL of 4-methyl-2-pentanone, and shake
vigorously. Allow to stand to separate the 4-methyl-2-pentanone layer, filter the layer, if necessary, and use the layer as the test solution. Separately, pipet exactly 5mL of standard lead solution, add water to make ex-actly 50mL, and to 2.0 mL of this solution, add 10 mL of a solution of diammonium hydrogen citrate (1 in 4) and 2 drops of bromothymol blue TS, then proceed in the same manner as for the test solution, and use the solution so obtained as the standard solution. Perform the test with the test solution and the standard solution, respectively, according to Atomic Absorption Spectro-photometry under the conditions described in Method 1, and determine the oncentration of lead in the test solu-tion.
(4) Cadmium Method 1: To 2.0 mL of standard cadmium solution, add 10mL of a solution of ammoni-um citrate (1 in 4) and 2 drops of bromothymol blue TS, and proceed in the same manner as for the test so-lution in Method 1, under (3), and use the soso-lution so obtained as the standard solution. Perform the test with the test solution obtained in Method 1, under (3) and the standard solution according to Atomic Absorption Spectrophotometry under the following conditions, and determine the concentration of cadmium in the test solution.
Gas: Dissolved Acetylene or hydrogen—Air.
Lamp: Cadmium hollow cathode lamp.
Wavelength: 228.8 nm.
Method 2: To 2.0 mL of standard cadmium solu-tion, add 10mL of a solution of ammonium citrate (1 in 4) and 2 drops of bromothymol blue TS, and proceed in the same manner as for the test solution in Method 2 under (3), and use the solution so obtained as the standard solution. Perform the test with the test solu-tion obtained in Method 2, under (3) and the standard solution according to Atomic Absorption Spectropho-tometry under the conditions described in Method 1, and determine the concentration of cadmium in the test solution.
(5) Tin Cut a container into pieces smaller than 5-mm square, place 5.0 g of the pieces in a Kjeldahl flask, add 30 mL of a mixture of sulfuric acid and nitric acid (1 : 1), and decompose by gentle heating in a muffle furnace, occasionally adding drop-wise a mixture of sulfuric acid and nitric acid (1 : 1) until the content changes to a clear, light brown solution. Then heat un-til the color of the solution changes to a clear, light yellow, and heat to slowly concentrate to practical dry-ness. After cooling, dissolve the residue in 5 mL of hydrochloric acid by warming, and after cooling, add water to make exactly 10 mL. Pipet exactly 5 mL of this solution into a 25 mL volumetric flask, A. Transfer the remaining solution to a 25 mL beaker, B by wash-ing out with 10mL of water, add 2 drops of bromocresol green TS, neutralize with diluted ammo-nia water (28) (1 in 2), and measure the volume con-sumed for neutralization as amL. To the volumetric flask, A, add potassium permanganate TS drop-wise
until a slight pale red color develops, and add a small amount of L-ascorbic acid to decolorize. Add 1.5 mL of 1 mol/L hydrochloric acid TS, 5 mL of a solution of citric acid (1 in 10), amL of diluted ammonia water (28) (1 in 2), 2.5 mL of polyvinyl alcohol TS, 5.0 mL of phenylfluorone-ethanol TS and water to make 25 mL.
Shake well, then allow to stand for about 20 minutes, and use this solution as the test solution. Separately, pipet exactly 1.0mL of standard tin solution, add 5mL of water, add potassium permanganate TS drop-wise until a slight pale red color develops, proceed in the same manner as for the test solution, and use this solu-tion as the standard solusolu-tion. Determine the absorbances of the test solution and the standard solu-tion, respectively, according to Spectrophotometry at 510 nm, using water as the blank.
Extractable substances
Cut the container at homogeneous regions of low curvature and preferably the same thickness, gather pieces to make a total surface area of about 1200 cm2 when the thickness is 0.5 mm or less, or about 600 cm2 when the thickness is greater than 0.5 mm, and subdi-vide in general into strips approximately 0.5 cm in width and 5 cm in length. Wash them with water, and dry at room temperature. Place these strips in a 300 mL hard glass vessel, add exactly 200 mL of water, and seal the opening with a suitable stopper. After heating the vessel in an autoclave at 121 °C for 1 hour, take out the vessel, allow to stand until the temperature falls to room temperature, and use the content as the test solu-tion.
For containers made of composite plastics, the ex-traction may be performed by filling a labeled volume of water in the container. In this case, it is necessary to record the volume of water used and the inside area of the container. When containers are deformed at 121 °C, the extraction may be performed at the highest temper-ature which does not cause deformation among the following conditions: at 100 ± 2 °C for 2 ± 0.2 hours, at 70 ± 2 °C for 24 ± 2 hours, at 50 ± 2 °C for 72 ± 2 hours, or at 37 ± 1 °C for 72 ± 2 hours. Prepare the blank solution with water in the same manner. For con-tainers made of composite plastics, water is used as the blank solution. Perform the following tests with the test solution and the blank solution:
(1) Foaming test Place 5mL of the test solution in a glass-stoppered test tube, about 15 mm in inside di-ameter and about 200 mm in length, shake vigorously for 3 minutes, and measure the time needed for almost complete disappearance of the foam thus generated.
(2) pH To 20 mL each of the test solution and the blank solution, add 1.0 mL of a solution of potassium chloride (1 in 1000), and obtain the difference in the reading of pH between these solutions.
(3) Potassium permanganate reducing substanc-es Place 20 mL of the tsubstanc-est solution in a glass-stoppered, conical flask, add 20.0 mL of 2 mmol/L potassium permanganate VS and 1mL of dilute sulfuric acid, and boil for 3 minutes. After cooling, add 0.10 g of
potas-sium iodide, stopper tightly, shake, then allow to stand for 10 minutes, and titrate with 0.01 mol/L sodium thiosulfate VS (indicator: 5 drops of starch TS). Per-form the test in the same manner, using 20.0 mL of the blank solution, and obtain the difference of the con-sumption of 2 mmol/L potassium permanganate VS between these solutions.
(4) Ultraviolet-visible spectrum Record the max-imum absorbances between 220 nm and 240 nm, and between 241 nm and 350 nm of the test solution against the blank solution as directed under the Untraviolet-visible Spectrophotometry.
(5) Residue on evaporation Evaporate 20 mL of the test solution on a waterbath to dryness, and weigh the residue after drying at 105 °C for 1 hour.
Test for fine particles
Rinse thoroughly with water the inside and out-side of containers to be used for the tests, fill the con-tainer with the labeled volume water for particle matter test or 0.9 w/v % sodium chloride solution, adjust so that the amount of air in the container is about 50mL per 500mL of the labeled volume, stopper tightly, and heat at 121 °C for 25 minutes in an autoclave. After allowing to cool for 2 hours, take out the container, and then allow to stand at ordinary temperature for about 24 hours. If the containers are deformed at 121 °C, employ a suitable temperature-time combination as directed under Extractable substances. Clean the out-side of the container, mix by turning upout-side-down 5 or 6 times, insert immediately a clean needle for filterless infusion into the container through the rubber closure of the container, take the effluent while mixing gently in a clean container for measurement, and use this solu-tion as the test solusolu-tion.
Fine particle test—Counting of the fine particles must be performed in dustless, clean facilities or appa-ratus, using a light-shielded automatic fine particle counter. The sensor of the counter to be used must be able to count fine particles of 1.5 µm or more in diame-ter. The volume to be measured is 10 mL. Adjust the counter before measurement. For calibration of the diameter and number of particles, the standard particles for calibration of the light-shielded automatic fine par-ticle counter should be used in suspension in water for particle matter test or 0.9 w/v % sodium chloride solu-tion. Count five times the numbers of particles with diameters of 5 to 10 µm, 10 to 25 µm, and more than 25 µm while stirring the test solution, and calculate the average particle numbers of four counts, excluding the first, as the number of particles in 1.0 mL of the test solution.
Reagent — Water for particle matter test and 0.9 w/v % sodium chloride solution to be used for the tests should not contain more than 0.5 particles of 5 to10 µm in size per 1.0 mL.
Transparency test
(1) Method 1 This can be applied to containers which have a smooth and not embossed surface and
rather low curvature. Cut the container at homogeneous regions of low curvature and preferably the same thickness to make 5 pieces of about 0.9 X 4 cm in size, immerse each piece in water filled in a cell for deter-mination of the ultraviolet spectrum, and determine the transmittance at 450 nm using a cell filled with water as a blank.
(2) Method 2 (Sensory test) This can be applied to containers which have a rough or embossed surface. It can also be applied to testing of the transparency of containers in case where the turbidity of their pharma-ceutical contents must be checked.
Reagents (i) Formadin standard suspension Di-lute 15 mL of the formadin stock suspension with wa-ter to make 1000 mL use within 24 hours of prepara-tion, Shake throughly befor use.
(ii) Reference suspension Dilute 50 mL of the formadin standard suspension with water to make 100 mL.
Tests (i) Method 2A (with control) Take 2 con-tainers to be tested, and place in one of them the la-beled volume of the reference suspension and in the other, the same volume of water. Show the two con-tainers to five subjects, separately, who do not know which one is which, ask which one seems to be more turbid, and calculate the rate of correct answers.
(ii) Method 2B (without control) Take 6 numbered containers to be tested, and place in three of them the labeled volume of the reference suspension and in the others, the same volume of water. Show each one of the containers at random order to five subjects, sepa-rately, who do not know which one is which, ask if it is turbid or not, and calculate the percentage of the an-swer that it is turbid (100X/15, X: number of contain-ers judged as “being turbid” in each group.
Water vapor permeability test
(1) Method 1 This test method is applicable to containers for aqueous injection. Fill the container with the labeled volume of water. After closing it hermeti-cally, accurately weigh the container and record the value. Store the container at 65 ± 5 % relative humidity and a temperature of 20 ± 2 °C for 14 days, and then accurately weigh the container again and record the value. Calculate the mass loss during storage.
(2) Method 2 This test method is provided for evaluating moisture permeability of containers for hy-groscopic drugs. Unless otherwise specified, perform the test according to the following procedure.
Desiccant—Place a quantity of calcium chloride for water determination in a shallow container, taking care to exclude any fine powder, then dry at 110 °C for 1 hour, and cool in a desiccator.
Procedure—Select 12 containers, clean their sur-faces with a dry cloth, and close and open each con-tainer 30 times in the same manner. Ten among the 12 containers are used as “test containers” and the remain-ing two, as "control containers” A torque for closremain-ing screw-capped containers is specified in the table. Add desiccant to 10 of the containers, designated test
con-tainers, filling each to within 13 mm of the closure if the container volume is 20 mL or more, or filling each to two-thirds of capacity if the container volume is less than 20 mL. If the interior of the container is more than 63 mm in depth, an inert filler or spacer may be placed in the bottom to minimize the total mass of the con-tainer and desiccant; the layer of desiccant in such a container shall be not less than 5 cm in depth. Close each container immediately after adding desiccant, applying the torque designated in the table. To each of the control containers, add a sufficient number of glass beads to attain a mass approximately equal to that of each of the test containers, and close, applying the torque designated in the table. Record the mass of the individual containers so prepared to the nearest 0.1 mg if the container volume is less than 20 mL, to the near-est l mg if the container volume is 20 mL or more but less than 200mL, or to the nearest 10 mg, if the con-tainer volume is 200mL or more, and store the contain-ers at 75 ± 3 % relative humidity and a temperature of 20 ± 2 °C. After 14 days, record the mass of the indi-vidual containers in the same manner. Completely fill 5 empty containers with water or a non-compressible, free-flowing solid such as fine glass beads, to the level indicated by the closure surface when in place. Trans-fer the contents of each to a graduated cylinder, and determine the average container volume, inmL. Calcu-late the rate of moisture permeability, in mg per day per liter, by use of the formula:
)]
V: Average volume (mL),
Tf-Ti: Difference between the final and initial masses of each test container (mg),
Cf-Ci: Average of the differences between the final and initial masses of the two controls (mg).
Table. Torque applicable to screw-type container Closure
Fill a container with a solution of fluorescein so-dium (1 in 1000), stopper tightly, place filter papers on
and under the container, and apply a pressure of 6.9 N (0.7 kg)/cm2 at 20 °C for 10 minutes. Judge the leaki-ness by observing the color of the paper.
Cytotoxicity test
The following test methods are designed to detect cytotoxic substances in plastic materials by evaluating the cytotoxicity of the culture medium extracts from plastic containers for pharmaceutical products. Other appropriate standard methods of cytotoxicity testing may be used for the evaluation, if appropriate. Howev-er, the final decision shall be made based upon the test methods given here, if the test results obtained accord-ing to the other methods are questionable.
(1) Cell line The recommended cell line is L929 (American Type Culture Collection-ATCC CCL1).
This cell line is subcultivated in Eagle’s minimum es-sential medium added with fetal calf serum. It is culti-vated with 5 ± 1 % carbon dioxide in concentration and 36 °C to 38 °C in temperature until the cell layer con-vers not less than 80 % of the plate. Check whether the cell layer is homogeneous and regular when the cell-culture medium is examined under a microscope. Other established cell lines may be used when it is confirmed that they form well-defined colonies reproducibly, with characteristics comparable to those of L929 cells.
(2) Culture medium Eagle’s minimum essential medi-um prepared as follows shall be used. Dissolve the chemicals listed below in 1000mL of water. Sterilize the solution by autoclaving at 121 °C for 20 minutes.
Cool the solution to room temperature, and add 22mL of sterilized sodium bicarbonate solution and 10mL of
Cool the solution to room temperature, and add 22mL of sterilized sodium bicarbonate solution and 10mL of