Revision Bulletin
`Official October 1, 2011
`
`Æ 788æ PARTICULATE MATTER IN
`INJECTIONS
`
`Change to read:
`
`This general chapter is harmonized with the correspond-
`ing texts of the European Pharmacopoeia and/or the Japa-
`nese Pharmacopoeia. These pharmacopeias have undertaken
`not to make any unilateral change to this harmonized
`chapter. Portions of the present general chapter text that
`are national USP text, and therefore not part of the harmo-
`nized text, are marked with symbols (F
`F) to specify this
`fact.
`Particulate matter in injections and parenteral infusions
`consists of extraneous mobile undissolved particles, other
`than gas bubbles, unintentionally present in the solutions.
`FAs stated in Injections Æ 1æ , solutions for injection adminis-
`tered by the intramuscular or subcutaneous route must
`meet the requirements of Particulate Matter in Injections
`Æ 788æ . •This requirement has been indefinitely postponed
`for products for veterinary use.• (RB 1-Oct-2011) Parenterals pack-
`aged and labeled exclusively for use as irrigating solutions
`are exempt from the requirements of Particulate Matter in
`Injections Æ 788æ . Radiopharmaceutical preparations are ex-
`empt from the requirements of Particulate Matter in Injec-
`tions Æ 788æ . Parenteral products for which the labeling spec-
`ifies use of a final filter prior to administration are exempt
`from the requirements of Particulate Matter in Injections
`Æ 788æ , provided that scientific data are available to justify
`this exemption.F
`For the determination of particulate matter, two proce-
`dures, Method 1 (Light Obscuration Particle Count Test) and
`Method 2 (Microscopic Particle Count Test), are specified
`hereinafter. When examining injections and parenteral infu-
`sions for subvisible particles, Method 1 is preferably applied.
`However, it may be necessary to test some preparations by
`the Light Obscuration Particle Count Test followed by the
`Microscopic Particle Count Test to reach a conclusion on con-
`formance to the requirements.
`Not all parenteral preparations can be examined for sub-
`visible particles by one or both of these methods. When
`Method 1 is not applicable, e.g., in the case of preparations
`having reduced clarity or increased viscosity, the test
`should be carried out according to Method 2. Emulsions,
`colloids, and liposomal preparations are examples. Similarly,
`products that produce air or gas bubbles when drawn into
`the sensor may also require microscopic particle count test-
`ing. If the viscosity of the preparation to be tested is suffi-
`ciently high so as to preclude its examination by either test
`method, a quantitative dilution with an appropriate diluent
`may be made to decrease viscosity, as necessary, to allow
`the analysis to be performed.
`The results obtained in examining a discrete unit or
`group of units for particulate matter cannot be extrapo-
`lated with certainty to other units that remain untested.
`Thus, statistically sound sampling plans must be developed
`if valid inferences are to be drawn from observed data to
`characterize the level of particulate matter in a large group
`of units.
`
`Æ 788æ Particulate Matter in Injections 1
`
`METHOD 1
`LIGHT OBSCURATION PARTICLE COUNT
`TEST
`
`Use a suitable apparatus based on the principle of light
`blockage that allows for an automatic determination of the
`size of particles and the number of particles according to
`size. The definition for particle-free water is provided in Rea-
`gent Specifications under Reagents, Indicators, and Solutions.
`The apparatus is calibrated using dispersions of spherical
`particles of known sizes between 10 m m and 25 m m. These
`standard particles are dispersed in particle-free water. Care
`must be taken to avoid aggregation of particles during dis-
`persion. FSystem suitability can be verified by using the
`USP Particle Count RS.F
`
`General Precautions
`
`The test is carried out under conditions limiting particu-
`late matter, preferably in a laminar flow cabinet.
`Very carefully wash the glassware and filtration equip-
`ment used, except for the membrane filters, with a warm
`detergent solution, and rinse with abundant amounts of
`water to remove all traces of detergent. Immediately before
`use, rinse the equipment from top to bottom, outside and
`then inside, with particle-free water.
`Take care not to introduce air bubbles into the prepara-
`tion to be examined, especially when fractions of the prep-
`aration are being transferred to the container in which the
`determination is to be carried out.
`In order to check that the environment is suitable for the
`test, that the glassware is properly cleaned, and that the
`water to be used is particle-free, the following test is carried
`out: determine the particulate matter in 5 samples of parti-
`cle-free water, each of 5 mL, according to the method de-
`scribed below. If the number of particles of 10 m m or
`greater size exceeds 25 for the combined 25 mL, the pre-
`cautions taken for the test are not sufficient. The prepara-
`tory steps must be repeated until the environment, glass-
`ware, and water are suitable for the test.
`
`Method
`
`Mix the contents of the sample by slowly inverting the
`container 20 times successively. If necessary, cautiously re-
`move the sealing closure. Clean the outer surfaces of the
`container opening using a jet of particle-free water and re-
`move the closure, avoiding any contamination of the con-
`tents. Eliminate gas bubbles by appropriate measures such
`as allowing to stand for 2 minutes or sonicating.
`For large-volume parenterals, single units are tested. For
`small-volume parenterals less than 25 mL in volume, the
`contents of 10 or more units are combined in a cleaned
`container to obtain a volume of not less than 25 mL; the
`test solution may be prepared by mixing the contents of a
`suitable number of vials and diluting to 25 mL with particle-
`free water or with an appropriate particle-free solvent when
`particle-free water is not suitable. Small-volume parenterals
`having a volume of 25 mL or more may be tested
`individually.
`Powders for parenteral use are reconstituted with particle-
`free water or with an appropriate particle-free solvent when
`particle-free water is not suitable.
`The number of test specimens must be adequate to pro-
`vide a statistically sound assessment. For large-volume
`parenterals or for small-volume parenterals having a volume
`of 25 mL or more, fewer than 10 units may be tested,
`using an appropriate sampling plan.
`
`ª 2011 The United States Pharmacopeial Convention All Rights Reserved.
`
`Page 1
`
`NPS EX. 2053
`CFAD v. NPS
`IPR2015-01093
`
`

`
`2 Æ 788æ Particulate Matter in Injections
`
`Remove four portions, not less than 5 mL each, and
`count the number of particles equal to or greater than 10
`m m and 25 m m. Disregard the result obtained for the first
`portion, and calculate the mean number of particles for the
`preparation to be examined.
`
`Evaluation
`
`For preparations supplied in containers with a nominal
`volume of more than 100 mL, apply the criteria of Test 1.A.
`For preparations supplied in containers with a nominal
`volume of less than 100 mL, apply the criteria of Test 1.B.
`For preparations supplied in containers with a nominal
`volume of 100 mL, apply the criteria of Test 1.B. [NOTE—
`Test 1.A is used in the Japanese Pharmacopoeia.]
`If the average number of particles exceeds the limits, test
`the preparation by the Microscopic Particle Count Test.
`Test 1.A (Solutions for parenteral infusion or solutions for
`injection supplied in containers with a nominal content of
`more than 100 mL)—The preparation complies with the test
`if the average number of particles present in the units
`tested does not exceed 25 per mL equal to or greater than
`10 m m and does not exceed 3 per mL equal to or greater
`than 25 m m.
`Test 1.B (Solutions for parenteral infusion or solutions for
`injection supplied in containers with a nominal content of less
`than 100 mL)—The preparation complies with the test if
`the average number of particles present in the units tested
`does not exceed 6000 per container equal to or greater
`than 10 m m and does not exceed 600 per container equal
`to or greater than 25 m m.
`
`METHOD 2
` MICROSCOPIC PARTICLE COUNT TEST
`
`Use a suitable binocular microscope, a filter assembly for
`retaining particulate matter, and a membrane filter for
`examination.
`The microscope is adjusted to 100 – 10 magnifications
`and is equipped with an ocular micrometer calibrated with
`an objective micrometer, a mechanical stage capable of
`holding and traversing the entire filtration area of the
`membrane filter, and two suitable illuminators to provide
`episcopic illumination in addition to oblique illumination.
`The ocular micrometer is a circular diameter graticule
`(see Figure 1) and consists of a large circle divided by
`crosshairs into quadrants, transparent and black reference
`circles 10 m m and 25 m m in diameter at 100 magnifica-
`tions, and a linear scale graduated in 10-m m increments. It
`is calibrated using a stage micrometer that is certified by
`either a domestic or international standard institution. A rel-
`ative error of the linear scale of the graticule within – 2% is
`acceptable. The large circle is designated the graticule field
`of view (GFOV).
`
`Revision Bulletin
`Official October 1, 2011
`
`Fig. 1. Circular diameter graticule. The large circle divided
`by crosshairs into quadrants is designated the graticule field
`of view (GFOV). Transparent and black circles having 10-
`m m and 25-m m diameters at 100· are provided as compari-
`son scales for particle sizing.
`
`Two illuminators are required. One is an episcopic
`brightfield illuminator internal to the microscope, the other
`is an external, focusable auxiliary illuminator that can be
`adjusted to give reflected oblique illumination at an angle
`of 10(cid:176) to 20(cid:176) .
`The filter assembly for retaining particulate matter con-
`sists of a filter holder made of glass or other suitable mate-
`rial, and is equipped with a vacuum source and a suitable
`membrane filter.
`The membrane filter is of suitable size, black or dark gray
`in color, nongridded or gridded, and 1.0 m m or finer in
`nominal pore size.
`
`General Precautions
`
`The test is carried out under conditions limiting particu-
`late matter, preferably in a laminar flow cabinet.
`Very carefully wash the glassware and filter assembly
`used, except for the membrane filter, with a warm deter-
`gent solution, and rinse with abundant amounts of water
`to remove all traces of detergent. Immediately before use,
`rinse both sides of the membrane filter and the equipment
`from top to bottom, outside and then inside, with particle-
`free water.
`In order to check that the environment is suitable for the
`test, that the glassware and the membrane filter are prop-
`erly cleaned, and that the water to be used is particle-free,
`the following test is carried out: determine the particulate
`matter of a 50-mL volume of particle-free water according
`to the method described below. If more than 20 particles
`10 m m or larger in size or if more than 5 particles 25 m m or
`larger in size are present within the filtration area, the pre-
`cautions taken for the test are not sufficient. The prepara-
`tory steps must be repeated until the environment, glass-
`ware, membrane filter, and water are suitable for the test.
`
`Method
`
`Mix the contents of the samples by slowly inverting the
`container 20 times successively. If necessary, cautiously re-
`move the sealing closure. Clean the outer surfaces of the
`
`ª 2011 The United States Pharmacopeial Convention All Rights Reserved.
`
`Page 2
`
`

`
`Revision Bulletin
`Official October 1, 2011
`
`container opening using a jet of particle-free water and re-
`move the closure, avoiding any contamination of the
`contents.
`For large-volume parenterals, single units are tested. For
`small-volume parenterals less than 25 mL in volume, the
`contents of 10 or more units are combined in a cleaned
`container; the test solution may be prepared by mixing the
`contents of a suitable number of vials and diluting to 25
`mL with particle-free water or with an appropriate particle-
`free solvent when particle-free water is not suitable. Small-
`volume parenterals having a volume of 25 mL or more may
`be tested individually.
`Powders for parenteral use are constituted with particle-
`free water or with an appropriate particle-free solvent when
`particle-free water is not suitable.
`The number of test specimens must be adequate to pro-
`vide a statistically sound assessment. For large-volume
`parenterals or for small-volume parenterals having a volume
`of 25 mL or more, fewer than 10 units may be tested,
`using an appropriate sampling plan.
`Wet the inside of the filter holder fitted with the mem-
`brane filter with several mL of particle-free water. Transfer to
`the filtration funnel the total volume of a solution pool or
`of a single unit, and apply a vacuum. If needed, add step-
`wise a portion of the solution until the entire volume is
`filtered. After the last addition of solution, begin rinsing the
`inner walls of the filter holder by using a jet of particle-free
`water. Maintain the vacuum until the surface of the mem-
`brane filter is free from liquid. Place the membrane filter in
`a Petri dish, and allow the membrane filter to air-dry with
`the cover slightly ajar. After the membrane filter has been
`dried, place the Petri dish on the stage of the microscope,
`scan the entire membrane filter under the reflected light
`from the illuminating device, and count the number of par-
`ticles that are equal to or greater than 10 m m and the
`number of particles that are equal to or greater than 25
`m m. Alternatively, partial membrane filter count and deter-
`mination of the total filter count by calculation is allowed.
`Calculate the mean number of particles for the preparation
`to be examined.
`The particle sizing process with the use of the circular
`diameter graticule is carried out by estimating the equiva-
`lent diameter of the particle in comparison with the 10 m m
`
`Æ 788æ Particulate Matter in Injections 3
`
`and 25 m m reference circles on the graticule. Thereby the
`particles are not moved from their initial locations within
`the graticule field of view and are not superimposed on the
`reference circles for comparison. The inner diameter of the
`transparent graticule reference circles is used to size white
`and transparent particles, while dark particles are sized by
`using the outer diameter of the black opaque graticule ref-
`erence circles.
`In performing the Microscopic Particle Count Test, do not
`attempt to size or enumerate amorphous, semiliquid, or
`otherwise morphologically indistinct materials that have the
`appearance of a stain or discoloration on the membrane
`filter. These materials show little or no surface relief and
`present a gelatinous or film-like appearance. In such cases,
`the interpretation of enumeration may be aided by testing
`a sample of the solution by the Light Obscuration Particle
`Count Test.
`
`Evaluation
`
`For preparations supplied in containers with a nominal
`volume of more than 100 mL, apply the criteria of Test 2.A.
`For preparations supplied in containers with a nominal
`volume of less than 100 mL, apply the criteria of Test 2.B.
`For preparations supplied in containers with a nominal
`volume of 100 mL, apply the criteria of Test 2.B. [NOTE—
`Test 2.A is used in the Japanese Pharmacopoeia.]
`Test 2.A (Solutions for parenteral infusion or solutions for
`injection supplied in containers with a nominal content of
`more than 100 mL)—The preparation complies with the test
`if the average number of particles present in the units
`tested does not exceed 12 per mL equal to or greater than
`10 m m and does not exceed 2 per mL equal to or greater
`than 25 m m.
`Test 2.B (Solutions for parenteral infusion or solutions for
`injection supplied in containers with a nominal content of less
`than 100 mL)—The preparation complies with the test if
`the average number of particles present in the units tested
`does not exceed 3000 per container equal to or greater
`than 10 m m and does not exceed 300 per container equal
`to or greater than 25 m m.
`
`ª 2011 The United States Pharmacopeial Convention All Rights Reserved.
`
`Page 3