Zalcitabine: White to off-white,crystalline powder.Soluble in water and in methanol;sparingly soluble in alcohol,in acetonitrile,in chloroform,and in methylene chloride;slightly soluble in cyclohexane.

Zein: White to yellow powder.Soluble in aqueous alcohols,in glycols,in ethylene glycol ethyl ether,in furfuryl alcohol,in tetrahydrofurfuryl alcohol,and in aqueous alkaline solutions of pH11.5or greater.Insoluble in water and in acetone;readily soluble in acetone-water mixtures between the limits of 60%and 80%of acetone by volume;insoluble in all anhydrous alcohols except methanol.

Zidovudine: White to yellowish powder.Melts at about 124.Exhibits polymorphism.Sparingly soluble in water;soluble in alcohol.

Zileuton: White to off-white powder.

Zinc Acetate: White crystals or granules,having a slight acetous odor and an astringent taste.Is slightly efflorescent.Freely soluble in water and in boiling alcohol;slightly soluble in alcohol.

Zinc Chloride: White or practically white,odorless,crystalline powder,or white or practically white crystalline granules.May also be in porcelain-like masses or molded into cylinders.Is very deliquescent.Asolution (1in 10)is acid to litmus.Very soluble in water;freely soluble in alcohol and in glycerin.Its solution in water or in alcohol is usually slightly turbid,but the turbidity disappears when a small quantity of hydrochloric acid is added.

Zinc Gluconate: White or practically white powder or granules.Soluble in water;very slightly soluble in alcohol.

Zinc Oxide: Very fine,odorless,amorphous,white or yellowish white powder,free from gritty particles.It gradually absorbs carbon dioxide from air.Insoluble in water and in alcohol;soluble in dilute acids.

Zinc Stearate: Fine,white,bulky powder,free from grittiness.Has a faint,characteristic odor.Is neutral to moistened litmus paper.Insoluble in water,in alcohol,and in ether.NFcategory:Tablet and/or capsule lubricant.

Zinc Sulfate: Colorless,transparent prisms,or small needles.May occur as a white,granular,crystalline powder.Is odorless and is efflorescent in dry air.Its solutions are acid to litmus.Very soluble in water (heptahydrate);freely soluble in water (monohydrate);freely soluble in glycerin (heptahydrate);practically insoluble in alcohol (monohydrate);insoluble in alcohol (heptahydrate).

Zinc Undecylenate: Fine,white powder.Practically insoluble in water and in alcohol.

Zolazepam Hydrochloride: White to off-white,crystalline powder.Freely soluble in water and in 0.1Nhydrochloric acid;soluble in methanol;slightly soluble in chloroform;practically insoluble in ether.