USP Caffeine RS— Do not dry. Keep container tightly closed. Protect from light.

USP Caffeine Melting Point RS— Dry portion over silica gel for 16 hours before using. When melted by the USP capillary tube method, Class Ia in the general chapter Melting Range or Temperature 741, the observed range falls within the indicated acceptance range. Keep container tightly closed and protected from light.

USP Calcifediol RS— Do not dry before using. Keep container tightly closed. Protect from light. Store in a freezer.

USP Calcium Ascorbate RS— Do not dry before using. Keep container tightly closed. Protect from light.

USP Calcium Gluceptate RS— This is the alpha form of Calcium Gluceptate. Dry portion in vacuum at 60 for 16 hours before using. Keep container tightly closed.

USP Calcium Lactobionate RS— Dry portion at 105 for 8 hours before using. Keep container tightly closed.

USP Calcium Pantothenate RS— Dry portion at 105 for 3 hours before using. Keep container tightly closed.

USP Calcium Saccharate RS— Do not dry before using. Keep container tightly closed.

USP Candelilla Wax RS —Do not dry. Keep container tightly closed.

USP Capreomycin Sulfate RS— Dry portion in vacuum at a pressure not exceeding 5 mm of mercury at 100 for 4 hours before using. Keep container tightly closed. Protect from light. Store in a cold place.

USP Caprylic Acid RS.

USP Caprylocaproyl Polyoxylglycerides RS— Do not dry. After opening the ampul, store the material in a tightly closed container.

USP Capsaicin RS— Dry portion at 40 in vacuum over phosphorus pentoxide for 5 hours before using. Keep container tightly closed, protected from light, and store in a cold place.

USP Captopril RS— Do not dry before using. Keep container tightly closed.

USP Captopril Disulfide RS— Do not dry before using. Keep container tightly closed.

USP Carbachol RS— Dry portion at 105 for 2 hours before using. Keep container tightly closed.

USP Carbamazepine RS— Dry portion at 105 for 2 hours before using. Keep container tightly closed.

USP Carbenicillin Indanyl Sodium RS— Do not dry. For quantitative applications determine the water content titrimetrically at the time of use. Keep container tightly closed. Protect from light. Store in a cold place.

USP Carbenicillin Monosodium Monohydrate RS— Do not dry before using. Keep container tightly closed. Protect from light. Store in a cold place.

USP Carbidopa RS— Do not dry before using. On a separate portion determine the Loss on drying at a pressure not exceeding 5 mm of mercury at 100 to constant weight, and apply correction for quantitative use. Keep container tightly closed. Protect from light.

USP Carbidopa Related Compound A RS [3-O-methylcarbidopa] (C11H16N2O4 240.26) —Do not dry. Keep container tightly closed. Protect from light.

USP Carbinoxamine Maleate RS— Dry portion at 105 for 2 hours before using. Keep container tightly closed. Protect from light.

USP Urea C 13 RS— Dry portion in vacuum at 40 for 3 hours before using. Preserve in tight, light-resistant containers.

USP Carboplatin RS— Do not dry. Keep container tightly closed. Protect from light. Store in a refrigerator.

USP Carisoprodol RS— Dry portion in vacuum at 60 for 3 hours before using. Keep container tightly closed.

USP Carteolol Hydrochloride RS— Dry portion at 105 for 3 hours before using. Keep container tightly closed.

USP Casticin RS— Do not dry. Keep container tightly closed. Store in a refrigerator. Protect from light.

USP Cathinone Hydrochloride RS [-aminopropiophenone hydrochloride] (C9H11NO·HCl 185.65) —Dry portion at 105 for 2 hours before using. Keep container tightly closed and protected from light.

USP Cefaclor RS— Do not dry. For quantitative applications determine the water content in percentage (W) titrimetrically at the time of use. Where calculation formulas require a correction factor use P = 1000 10W. Keep container tightly closed, protected from light, and store in a refrigerator.

USP Cefaclor Delta-3 Isomer RS —Do not dry before using. Keep container tightly closed, and store in a freezer.

USP Cefadroxil RS— Do not dry before using. This is the monohydrate form of cefadroxil. Keep container tightly closed. Protect from light. Store in a cold place.

USP Cefamandole Lithium RS— Do not dry before using. Keep container tightly closed. Protect from light. Store in a cold place.

USP Cefamandole Nafate RS— Do not dry before using. Keep container tightly closed. Protect from light. Store in a cold place.

USP Cefazolin RS— Do not dry before using. For quantitative applications, determine the water content titrimetrically at the time of use. Keep container tightly closed. Protect from light. Store in a refrigerator.

USP Cefepime Hydrochloride RS —Do not dry before using. Store in a cold place. Protect from light. For quantitative applications, determine the water titrimetrically at the time of use.

USP Cefepime Hydrochloride System Suitability RS— This is a mixture of cefepime hydrochloride related compound A ([6R-[6,7(E)]]-1-[[7-[[(2-amino-4-thiazolyl) (methoxyimino)acetyl]amino]-2-carboxy-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-en-3-yl]methyl]-1-methylpyrrolidinium chloride, monohydrochloride, monohydrate; (C19H25ClN6O5S2·HCl·H2O 571.50); cefepime related compound B ([6R-trans]-7-[[[2-[[(2-amino-4-thiazolyl)(methoxyimino)acetyl]amino]-4-thiazolyl](methoxyimino)acetyl]amino]-3-(1-methylpyrrolidinium-1-yl)methyl]-5-thia-1-azabicyclo[4.2.0]oct-3-ene-2-carboxylic acid, inner salt; (C25H29N9O7S3 663.75); and cefepime hydrochloride. Do not dry before using. Keep container tightly closed. Store in the dark, in a cold place.

USP Cefixime RS— This is the trihydrate form of cefixime. Do not dry. For quantitative applications determine the water content titrimetrically at the time of use, and use a value of 986 µg of cefixime per mg on the anhydrous basis. Keep container tightly closed.

USP Cefmenoxime Hydrochloride RS— Do not dry before using. For quantitative applications, determine the water content titrimetrically at the time of use. Keep container tightly closed, protected from light and moisture, and store in a refrigerator.

USP Cefmetazole RS— Do not dry before using. Keep container tightly closed, protected from light, and store in a cold place.

USP Cefonicid Sodium RS— Do not dry; determine the water content titrimetrically at the time of use. Keep container tightly closed, and store in a cold, dry place, protected from light.

USP Cefoperazone Dihydrate RS— Do not dry before using. Keep container tightly closed. Protect from light. Store in a cold place.

USP Ceforanide RS— Do not dry before using. Keep container tightly closed. Protect from light. Store in a cold place.

USP Cefotaxime Sodium RS— Do not dry. Keep container tightly closed. Protect from light. Store in a refrigerator.

USP Cefotetan RS— Do not dry before using. For quantitative applications, determine the water content titrimetrically at the time of use. Keep container tightly closed, protected from light, and store in a freezer.

USP Cefotiam Hydrochloride RS— Do not dry before using. For quantitative applications, determine the water content titrimetrically prior to use. Keep container tightly closed, protected from light and moisture, and store at a temperature not exceeding 5. Prepare solutions immediately prior to use.

USP Cefoxitin RS— This is the monohydrate form. Do not dry. For quantitative applications, determine the water content titrimetrically. Keep container tightly closed. Protect from light. Store in a freezer.USP29

USP Cefpiramide RS— Do not dry. For quantitative applications, determine the water content titrimetrically at the time of use. Keep container tightly closed. Protect from light. Store in a freezer.

USP Cefpodoxime Proxetil RS— Do not dry; determine the water content titrimetrically on a separate portion prior to use. Keep container tightly closed. Protect from light. Store in a refrigerator.

USP Cefprozil (E)-Isomer RS— Do not dry before using. Keep container tightly closed.

USP Cefprozil (Z)-Isomer RS— Do not dry. Keep container tightly closed. Store in a freezer.

USP Ceftazidime Delta-3-Isomer RS— Do not dry before using. Keep container tightly closed. Protect from light. Store in a freezer.

USP Ceftazidime Pentahydrate RS— Do not dry before using. Keep container tightly closed. Protect from light, air, and moisture. Store in a freezer.

USP Ceftizoxime RS— Do not dry before using. Keep container tightly closed. Protect from light. Store in a cold, dry place.

USP Ceftriaxone Sodium RS— Do not dry before using. For quantitative applications, determine the water content titrimetrically at the time of use. Store in a refrigerator. Keep container tightly closed.

USP Ceftriaxone Sodium E-Isomer RS— Do not dry before using. Keep container tightly closed, protected from light, and store in a cold place.

USP Cefuroxime Axetil RS— Do not dry before using. For quantitative applications, determine the water content titrimetrically at the time of use. Keep container tightly closed, store in a refrigerator, and protect from light.

USP Cefuroxime Axetil Delta-3 Isomers RS— Do not dry. Keep container tightly closed, protected from light, and store in a freezer.

USP Cefuroxime Sodium RS— Do not dry before using. Keep container tightly closed. Protect from light. Store in a cold, dry place.

USP Cellaburate RS— Dry a portion at 105 for 1 hour before using. Keep container tightly closed. Protect from light, and store in a cold place.

USP Cellacefate RS— Do not dry. Keep container tightly closed.

USP F1 Cells for Cell Proliferation Test RS (ATCC cell line FDCP-F1 shipped with approval from USP)—Store in a tight container in a freezer.

USP Cellulose Acetate RS— Dry portion at 105 for 3 hours before using. Keep container tightly closed.

USP Cephaeline Hydrobromide RS— Dry a portion at 105 to constant weight before using. Keep container tightly closed. Protect from light.

USP Cephalexin RS— Do not dry before using. This is the monohydrate form of cephalexin. Keep container tightly closed. For quantitative applications, determine the water content titrimetrically at the time of use.

USP Cephalothin Sodium RS— Dry portion in vacuum at a pressure not exceeding 5 mm of mercury at 60 for 3 hours before using. Keep container tightly closed. Protect from light. Store in a cold place.

USP Cephapirin Benzathine RS— Do not dry before using. Keep container tightly closed.

USP Cephapirin Sodium RS— Do not dry before using. Keep container tightly closed. Protect from light. Store in a cold, dry place.

USP Cephradine RS— Do not dry before using. This is the Dihydrate form of cephadrine. Keep container tightly closed. Protect from light. Store in a cold place.

USP Cetyl Alcohol RS— Do not dry before using. Keep container tightly closed.

USP Cetyl Palmitate RS— Do not dry before using. Store at room temperature not exceeding 30. Protect from light.

USP Cetylpyridinium Chloride RS— Do not dry before using. For quantitative applications determine the water content titrimetrically at the time of use. Keep container tightly closed.

USP Chlorambucil RS— [Caution—Avoid contact. ] Dry portion over silica gel for 24 hours before using. Keep container tightly closed. Protect from light.

USP Chloramphenicol RS— Do not dry before using. Keep container tightly closed. Store in a cold dry place.

USP Chloramphenicol Palmitate RS— Do not dry before using. Keep container tightly closed. Protect from light. Store in a cold place.

USP Chloramphenicol Palmitate Nonpolymorph A RS— Do not dry before using. Keep container tightly closed. Protect from light. Store in a cold place.

USP Chloramphenicol Palmitate Polymorph A RS— Do not dry before using. Keep container tightly closed and store in a cold, dry place.

USP Chlordiazepoxide RS— Dry portion at 105 for 3 hours before using. Keep container tightly closed. Protect from light.

USP Chlordiazepoxide Related Compound A RS [7-chloro-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one 4-oxide] (C15H11ClN2O2 286.72) —Dry portion over silica gel for 4 hours before using. Keep container tightly closed and protected from light.

USP Chlordiazepoxide Hydrochloride RS— Dry portion in vacuum over phosphorus pentoxide at 60 for 4 hours before using. Keep container tightly closed. Protect from light.

USP Chlorhexidine RS— Keep container tightly closed. Protect from light. Store in a refrigerator.

USP Chlorhexidine Acetate RS— Do not dry. For quantitative applications, determine the water content titrimetrically at the time of use. Keep container tightly closed. Protect from light. Store in a refrigerator.

USP Chlorhexidine Related Compounds RS— Do not dry. Keep container tightly close. Protect from light. Store in a refrigerator.

USP Chlorobutanol RS— Do not dry before using. This is the hydrous form of chlorobutanol. Keep container tightly closed.

USP 2-Chloro-3,5-dimethylphenol RS (C8H9ClO 156.61) —Do not dry before using. Keep container tightly closed.

USP Chlorogenic Acid RS.

USP -Chlorogenin RS— Do not dry before using. Keep container tightly closed. Protect from light. Store in a cold place.

USP Chlorophyllin Copper Complex Sodium RS.

USP 4¢-Chloro-3¢-sulfamoyl-2-benzophenone Carboxylic Acid RS— (NAME CHANGE) See USP Chlorthalidone Related Compound A RS.

USP Chloroprocaine Hydrochloride RS— Dry portion at 105 for 2 hours before using. Keep container tightly closed.

USP Chloroquine Phosphate RS— Dry portion at 105 for 16 hours before using. Keep container tightly closed.

USP Chlorothiazide RS— Dry portion at 105 for 1 hour before using. Keep container tightly closed. Store in a cold place.

USP Chloroxylenol RS— Do not dry before using. Keep container tightly closed.

USP Chloroxylenol Related Compound A RS [2-chloro-3,5-dimethylphenol] —Do not dry before using. Keep container tightly closed.

USP Chlorpheniramine Extended-Release Tablets RS (Drug Release Calibrator, Single Unit) —Use in conjunction with the test for Drug Release 724. The label states the nominal weight of chlorpheniramine maleate in each tablet. Use only whole tablets. Remove any surface dust with a soft brush before using. Keep container tightly closed and avoid exposure to excessive humidity.

USP Chlorpheniramine Maleate RS —Do not dry. Keep container tightly closed. Protect from light.

USP Chlorpromazine Hydrochloride RS —Dry portion at 105 for 2 hours before using. Keep container tightly closed. Protect from light.

USP Chlorpropamide RS —Dry portion in vacuum at 60 for 2 hours before using. Keep container tightly closed.

USP (E)-Chlorprothixene RS —Keep container tightly closed and protected from light. Dry portion over silica gel to constant weight before using.

USP Chlortetracycline Hydrochloride RS —Do not dry before using. Keep container tightly closed. Protect from light. Store in a freezer.

USP Chlorthalidone RS —Dry portion at 105 for 4 hours before using. Keep container tightly closed.

USP Chlorthalidone Related Compound A RS [4¢-Chloro-3¢-sulfamoyl-2-benzophenone Carboxylic Acid]— Do not dry. Keep container tightly closed. Store in a desiccator.

USP Chlorzoxazone RS —Dry portion at 105 for 2 hours before using. Keep container tightly closed.

USP Chlorzoxazone Related Compound A RS [2-amino-4-chlorophenol] (C6H6ClNO 143.57) — Dry portion at 105 for 2 hours before using. Keep container tightly closed, protected from light, and store in a cold, dry place.

USP Cholecalciferol RS —Store in a cold place, protected from light. Allow it to attain room temperature before opening ampul. Use the material promptly and discard the unused portion.

USP D4,6-Cholestadienol RS [cholesta-4,6-dien-3-ol] (C27H44O 384.64) —Do not dry. Transfer unused contents to a tightly closed container, and store under nitrogen, in the dark, in a cool place.

USP Cholesteryl Caprylate RS (C35H60O2 512.86) —Dry portion in vacuum over silica gel for 4 hours before using. Keep container tightly closed and protected from light.

USP Cholestyramine Resin RS —Dry portion in a suitable vacuum drying tube over phosphorus pentoxide at a pressure not exceeding 50 mm of mercury at 70 for 16 hours before using. Keep container tightly closed.

USP Choline Bitartrate RS— Dry at 65 in vacuum for 4 hours before using. Keep container tightly closed. Store in a desiccator. This material is hygroscopic.

USP Choline Chloride RS— Dry at 65 in vacuum for 4 hours before using. Keep container tightly closed. Store in a desiccator. This material is extremely hygroscopic.

USP Chondroitin Sulfate Sodium RS— Dry a portion at 105 for 4 hours just before use. [NOTE—This material is extremely hygroscopic once dried. Weigh promptly, avoiding moisture from the environment.] Keep container tightly closed.

USP Chorionic Gonadotropin RS —Store in a refrigerator and do not dry before using. Use a fresh ampul for each group of assays and discard any unused portion.

USP Chromium Picolinate RS— Dry portion at 105 for 4 hours before using. Keep container tightly closed.

USP Chymotrypsin RS— Keep container tightly closed, and store in a refrigerator. Allow contents to reach room temperature before opening, and do not dry before using. Protect from light. Determine loss on drying on a separate portion in a vacuum oven at 60 for 4 hours.

USP Ciclopirox RS —Do not dry. Keep container tightly closed. Store in a refrigerator.USP29

USP Ciclopirox Related Compound A RS [3-cyclohexyl-4,5-dihydro-5-methyl-5-isoxazolyl acetic acid] —Do not dry. Keep container tightly closed. Store in a refrigerator.USP29

USP Ciclopirox Related Compound B RS [6-cyclohexyl-4-methyl-2-pyrone] —Do not dry. Keep container tightly closed. Protect from light. Store in a refrigerator.USP29

USP Ciclopirox Olamine RS— Dry a portion in vacuum to constant weight before using. Keep container tightly closed.

USP Cilastatin Ammonium Salt RS— Do not dry before using. Keep container tightly closed, and store in a freezer under nitrogen.

USP Cimetidine RS— Do not dry. Keep container tightly closed. Protect from light. Store at room temperature.

USP Cimetidine Hydrochloride RS— Do not dry before using. Keep container tightly closed. Protect from light.

USP Cinoxacin RS— Dry portion in vacuum at 60 for 3 hours before using. Keep container tightly closed.

USP Ciprofloxacin RS— Do not dry before using. Keep container tightly closed. Protect from light.

USP Ciprofloxacin Ethylenediamine Analog RS [1-cyclopropyl- 6-fluoro-1,4-dihydro-4-oxo-7-[(2-aminoethyl)amino]-3-quinolinecarboxylic acid hydrochloride] (C15H16FN3O3·HCl 341.77) —Do not dry before using. Keep container tightly closed. Keep container tightly closed.

USP Ciprofloxacin Hydrochloride RS— This is the monohydrate form of ciprofloxacin hydrochloride. Do not dry; determine the water content titrimetrically when used for quantitative analysis. Keep container tightly closed. Protect from light.

USP Cisplatin RS— Do not dry before using. Keep container tightly closed. Protect from light.

USP Citric Acid RS— Dry portion at 105 for 2 hours before using. Keep container tightly closed. This material is the anhydrous form of citric acid.

USP Clarithromycin RS— Do not dry before using. Keep container tightly closed.

USP Clarithromycin Identity RS. USP29

USP Clarithromycin Related Compound A RS [6,11-di-O-methylerythromycin A] (C39H71NO13 762.00) — Do not dry before using. Keep container tightly closed, and store in a refrigerator.

USP Clavam-2-Carboxylate Potassium RS— Each vial contains 3 µg of clavam-2-carboxylate potassium dispersed in poly(vinylpyrrolidone). For quantitative applications, reconstitute the entire contents with a suitable volume of water. Do not dry. Keep container tightly closed. Protect from light. Store in a freezer. Standard solutions may be stored in a refrigerator for 1 week.

USP Clavulanate Lithium RS— Do not dry before using. Keep container tightly closed and protected from light. Store in a cold place.

USP Clemastine Fumarate RS— Do not dry. Keep container tightly closed. Protect from light.

USP Clidinium Bromide RS— Dry portion at 105 for 3 hours before using. Keep container tightly closed. Protect from light.

USP Clidinium Bromide Related Compound A RS [3-hydroxy-1-methylquinuclidinium bromide] (C8H16BrNO 222.13) —Dry portion over silica gel for 4 hours before using. Keep container tightly closed and protected from light.

USP Clindamycin Hydrochloride RS— Do not dry before using. This is the monohydrate form. Keep container tightly closed. Store in a cold place.

USP Clindamycin Palmitate Hydrochloride RS— Do not dry. Keep container tightly closed. Store in a freezer.USP29

USP Clindamycin Phosphate RS— Do not dry. Keep container tightly closed. Protect from light. Store in a cool, dry place.

USP Clioquinol RS— Dry portion over phosphorus pentoxide for 5 hours before using. Keep container tightly closed. Protect from light.

USP Clobetasol Propionate RS— Do not dry before using. Keep container tightly closed and protected from light.

USP Clobetasol Propionate Related Compound A RS [9-fluoro-11-hydroxy-16-methyl 3-oxo-androsta-1,4-diene-17(R)-spiro-2¢-[4¢-chloro-5¢-ethylfuran-3¢(2¢H)-one]] (C25H30ClFO4 448.96) —Do not dry before using. Keep container tightly closed and protected from light.

USP Clocortolone Pivalate RS— Dry portion at 105 for 3 hours before using. Keep container tightly closed. Protect from light.

USP Clofazimine RS— Dry portion at 105 for 3 hours before using. Keep container tightly closed, protect from light, and store at room temperature.

USP Clofibrate RS— After opening ampul, store in a tight, light-resistant container. Do not dry before using.

USP Clomiphene Citrate RS— Do not dry; determine the water content titrimetrically at time of use. Keep container tightly closed.

USP Clomiphene Related Compound A RS [(E,Z)-2-[4-(1,2-diphenylethenyl)phenoxy]-N,N-diethylethanamine hydrochloride] (C26 H29NO·HCl 407.98) —Do not dry before using. Keep container tightly closed.

USP Clomipramine Hydrochloride RS— Do not dry. This material is hygroscopic. Keep container tightly closed.

USP Clonazepam RS— Do not dry.USP29 Keep container tightly closed. Protect from light.

USP Clonazepam Related Compound A RS [3-amino-4-(2-chlorophenyl)-6-nitrocarbostyril] (C15H10CIN3O3 315.72) —Do not dry. Keep container tightly closed and protected from light.

USP Clonazepam Related Compound B RS [2-amino-2¢-chloro-5-nitrobenzophenone] (C13H9ClN2O3 276.68) —Do not dry before using. Keep container tightly closed and protected from light.

USP Clonazepam Related Compound C RS [2-bromo-2¢-(2-chlorobenzoyl)-4¢-nitroacetanilide]— Do not dry. Keep container tightly closed. Protect from light. Store in a refrigerator.

USP Clonidine RS— Do not dry before using. Keep container tightly closed. Protect from light.

USP Clonidine Hydrochloride RS— Dry portion at 105 to constant weight before using. Keep container tightly closed.

USP Clonidine Related Compound B RS [2-[(E)-2,6-dichlorophenylimino]-1-(1-{2-[(E)-2,6-dichlorophenylimino]-imidazolidin-1- yl}-ethyl)-imidazolidine] (C21H21Cl4N5 485.24) —Do not dry. Keep container tightly closed. Protect from light.

USP Clopidogrel Bisulfate RS.

USP Clopidogrel Related Compound A RS [(+)-(S)-(o-chlorophenyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4H)-acetic acid].

USP Clopidogrel Related Compound B RS [methyl (±)-(o-chlorophenyl)-4,5-dihydrothieno[2,3-c]pyridine-6(7H)-acetate, hydrogen sulfate].

USP Clopidogrel Related Compound C RS [methyl ()-(R)-o-chlorophenyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4H)-acetate, hydrogen sulfate].

USP Clorazepate Dipotassium RS— Do not dry. Store under nitrogen. Keep container tightly closed. Protect from light.

USP Clorsulon RS— Dry portion in vacuum at 100 for 4 hours before using. Keep container tightly closed. Protect from light.

USP Clotrimazole RS— Do not dry. Keep container tightly closed. Protect from light.

USP Clotrimazole Related Compound A RS [(o-chlorophenyl)diphenylmethanol] (C19H15ClO 294.78) —Do not dry before using. Keep container tightly closed and protected from light.

USP Powdered Red Clover Extract RS— Do not dry. Keep container tightly closed. Protect from light. Store in a refrigerator.

USP Cloxacillin Benzathine RS— Do not dry before using. Keep container tightly closed. Protect from light.

USP Cloxacillin Sodium RS— Do not dry before using. This is the monohydrate form of cloxacillin sodium. Keep container tightly closed, protected from light, and store in a freezer.

USP Clozapine RS— Dry at 105 for 4 hours before using. Keep container tightly closed.

USP Cocaine Hydrochloride RS— Dry portion over silica gel for 3 hours before using. Keep container tightly closed. Protect from light.

USP Cod Liver Oil RS.

USP Codeine N-Oxide RS (C18H21NO4 315.37) —Store in a tightly closed container, protected from light. Do not dry before using.

USP Codeine Phosphate RS— This is the hemihydrate form of codeine phosphate. Dry portion at 105 for 18 hours before using. Keep container tightly closed. Protect from light.

USP Codeine Sulfate RS— Dry portion at 105 for 3 hours before using. Keep container tightly closed. Protect from light.

USP Powdered Black Cohosh Extract RS— Do not dry. Keep container tightly closed. Store in a refrigerator. This material is hygroscopic.

USP Colchicine RS— Do not dry. For quantative use, determine the water content titrimetrically and correct for labeled solvent content at time of use. Keep container tightly closed. Protect from light. Store in a cold, dry place.

USP Colestipol Hydrochloride RS— Do not dry before using. Keep container tightly closed, and store over a desiccant.

USP Colistimethate Sodium RS— Dry portion in vacuum at a pressure not exceeding 5 mm of mercury at 60 for 3 hours before using. Keep container tightly closed. Protect from light. Store in a cold place.

USP Colistin Sulfate RS— Dry portion in vacuum at a pressure not exceeding 5 mm of mercury at 60 for 3 hours before using. Keep container tightly closed. Protect from light. Store in a cold place.

USP Copovidone RS— Dry portion at 105 for 3 hours before using. Keep container tightly closed.

USP Corticotropin RS— Do not dry before using. Store at a temperature of 0 or below.

USP Cortisone Acetate RS— Dry portion at 105 for 30 minutes before using. Keep container tightly closed.

USP Creatinine RS— Dry portion at 105 for 3 hours before using. Keep container tightly closed.

USP Cromolyn Sodium RS— Do not dry; determine the water content titrimetrically at the time of use. Keep container tightly closed.

USP Crospovidone RS— Dry portion in vacuum at 105 for 1 hour before using. Keep container tightly closed. Store in a desiccator once removed from hermetic bag. This material is hygroscopic.

USP Crotamiton RS— Do not dry before using. After opening the ampul, store in a tightly closed container, protected from light in a desiccator.

USP Cyclandelate RS— Dry portion over silica gel for 24 hours before using. Keep container tightly closed. Store in a refrigerator. Protect from light.

USP Cyanocobalamin RS— Dry portion over silica gel for 4 hours before using. Keep container tightly closed and protected from light.

USP Cyclizine Hydrochloride RS— Dry portion at 120 for 3 hours before using. Keep container tightly closed. Protect from light.

USP Cyclobenzaprine Hydrochloride RS— Dry portion at 105 to constant weight before using. Keep container tightly closed.

USP Alpha Cyclodextrin RS— Do not dry before using. Keep container tightly closed.

USP Beta Cyclodextrin RS— Do not dry before using. Determine the water content titrimetrically when used for quantitative analyses. Keep container tightly closed.

USP Gamma Cyclodextrin RS.

USP Cyclomethicone 4 RS— After opening, store in a tightly closed container.

USP Cyclomethicone 5 RS— Do not dry. After opening ampul, store the material in a tightly closed container.

USP Cyclomethicone 6 RS— After opening, store in a tightly closed container.

USP Cyclopentolate Hydrochloride RS— Dry portion at 105 for 4 hours before using. Use solutions immediately after preparation. Keep container tightly closed. Store in a refrigerator.

USP Cyclophosphamide RS— Do not dry; determine the water content titrimetrically when used for quantitative analyses. Keep container tightly closed, and store between 2 and 8.

USP 2-Cyclopropylmethylamino-5-chlorobenzophenone RS— Do not dry before using. Keep container tightly closed. Protect from light.

USP Cycloserine RS— Dry portion in vacuum at a pressure not exceeding 5 mm of mercury at 60 for 3 hours before using. Keep container tightly closed.

USP Cyclosporine RS— Dry portion before use in a capillary-stoppered bottle in vacuum at a pressure not exceeding 5 mm of mercury at 60 for 3 hours. Keep container tightly closed, protected from light, and store in a cold place. Where calculations require a purity factor, use P = 1000.

USP Cyclosporine Resolution Mixture RS— This material is a 100:1 mixture of cyclosporine and cyclosporine U. Do not dry before using. Keep container tightly closed, protected from light, and store in a cold place.

USP Cyproheptadine Hydrochloride RS— Do not dry; determine the water content titrimetrically when used for quantitative analyses. Keep container tightly closed.

USP L-Cysteine Hydrochloride RS— This is the monohydrate form of L-cysteine hydrochloride. Dry portion at a pressure not exceeding 5 mm of mercury for 24 hours before using. Keep container tightly closed.

USP Cytarabine RS— Dry portion at a pressure not exceeding 5 mm of mercury at 60 for 3 hours before using. Keep container tightly closed. Protect from light.