USP Halcinonide RS— Dry portion in vacuum at 100 for 3 hours before using. Keep container tightly closed. Protect from light. Store in a refrigerator.

USP Haloperidol RS— Dry portion in vacuum at 60 for 3 hours before using. Keep container tightly closed. Protect from light.

USP Haloperidol Related Compound A RS [4,4¢-bis[4-p-chlorophenyl)-4-hydroxypiperidino]butyrophenone] (C32H36Cl2N2O3 567.56) —Do not dry. Keep container tightly closed. Protect from light.

USP Halothane RS— Do not dry. Material is highly volatile. After opening ampul, store in a tightly closed, light-resistant container. Store in a refrigerator.

USP Hemoglobin RS.

USP Heparin Sodium RS— Store in a cool place and do not freeze.

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

USP Hexachlorophene RS— Dry portion at 105 for 4 hours before using. Keep container tightly closed. Protect from light. Store in a cool, dry place.

USP Hexacosanol RS.

USP 2E,4E-Hexadienoic Acid Isobutylamide RS— Do not dry. Keep container tightly closed. Store in a refrigerator. Protect from light.

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

USP Hexylresorcinol RS— Dry over silica gel for 4 hours before using. Keep container tightly closed.

USP Histamine Dihydrochloride RS— Dry portion over silica gel for 2 hours before using. Keep container tightly closed. Protect from light.

USP L-Histidine RS— Do not dry before using. Keep container tightly closed.

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

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

USP Homopolymer Polypropylene RS— Exercise care in handling and storage to avoid scratching surface of strips. Prepare samples as directed in the respective USP General Test Chapter.

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

USP Hyaluronidase RS— This is a mixture of hyaluronidase and lactose. Do not dry before using. Keep container tightly closed, and store in a cool, dry place, preferably under refrigeration in a desiccator.

USP Hydralazine Hydrochloride RS— Dry it at 110 for 15 hours before using. Keep container tightly closed. Store in a dry place.

USP Hydrochlorothiazide RS— Dry portion at 105 for 1 hour before using. Keep container tightly closed.

USP Hydrocodone Bitartrate RS— Dry portion in vacuum at 105 for 2 hours before using. [NOTE—Hydrocodone Bitartrate, after drying, is extremely hygroscopic. After drying, immediately transfer the material to a desiccator containing phosphorus pentoxide.] Protect from light.

USP Hydrocodone Bitartrate Related Compound A RS— Do not dry. Keep container tightly closed.

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

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

USP Hydrocortisone Butyrate RS— Dry portion in vacuum at 78 for 3 hours before using. Keep container tightly closed.

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

USP Hydrocortisone Phosphate Triethylamine RS (C21H31O8P· C6H15N 543.64) —Dry portion in vacuum at 60 for 3 hours before using. Keep container tightly closed.

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

USP Hydroflumethiazide RS— Dry portion over silica gel for 4 hours before using. Keep container tightly closed.

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

USP Hydroquinone RS— Do not dry; determine the water content by the titrimetric method before using for quantitative analyses. Keep container tightly closed. Protect from light.

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

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

USP Hydroxyprogesterone Caproate RS— Dry portion in vacuum over silica gel for 4 hours before using. Keep container tightly closed. Protect from light.

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

USP Hydroxypropyl Methylcellulose RS— (NAME CHANGE) See USP Hypromellose RS.

USP Hydroxyurea RS— [Caution—Hygroscopic; decomposes in the presence of moisture. ] Dry portion in vacuum at 60 for 3 hours before using. Keep container tightly closed. Store in a desiccator at 0 or less.

USP Hydroxyzine Hydrochloride RS— [Caution—The dried material is hygroscopic. ] Dry portion in vacuum at 75 for 3 hours before using. Keep container tightly closed. Store in a refrigerator.

USP Hydroxyzine Related Compound A RS [p-chlorobenzhydrylpiperazine]— Do not dry; use as is. Keep container tightly closed.

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

USP Hyoscyamine Sulfate RS— Dry portion in vacuum at 105 for 16 hours before using. Keep container tightly closed. Protect from light.

USP Hypericin RS.

USP Hyperoside RS.

USP Hypromellose RS— Dry portion at 105 for 2 hours before using. Keep container tightly closed. This material is hygroscopic.

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