Pharmacy Questions and Answers

Answer: C

Laminar air flow is used to produce the aseptic environment.

A laminar air flow bench blows air through a HEPA filter, which removes particles and microorganisms, and moves it across the work area in parallel streams at uniform speed. The steady flow sweeps contaminants away from the work, so sterile products such as eye drops and injections can be prepared and manipulated aseptically.

It protects a work zone, not the whole room. It does not clean the room of dust or remove toxic materials, and its purpose is sterility rather than 'fresh air'.

Answer: B

Latanoprost is commonly given as eye drops.

It is a prostaglandin F2-alpha analogue used once daily as 0.005 percent eye drops in open-angle glaucoma and ocular hypertension. It lowers intraocular pressure by increasing the outflow of aqueous humour through the uveoscleral route. Local side effects include darkening of the iris and longer eyelashes.

It is not given as an oral tablet, an injection or a skin cream.

Answer: D

The test that is not an evaluation test for ophthalmic preparations is the pyrogen test.

Pyrogens are fever-producing substances, mainly bacterial endotoxins. The pyrogen test (or bacterial endotoxin test) applies to parenteral preparations, which enter the bloodstream directly. Eye drops are applied to the surface of the eye, so the test is not among their standard evaluations.

Ophthalmic preparations must be sterile, so the sterility test applies. A clarity test checks solutions for visible particles, and a leaker test checks that the sealed containers do not leak.

Answer: A

Solutions are monophasic dosage forms.

In a solution the drug is completely dissolved, so the preparation is one clear, uniform phase. Syrups, elixirs, mouthwashes and solution eye drops are monophasic liquid dosage forms.

Biphasic liquids have two phases: suspensions (solid particles dispersed in a liquid) and emulsions (droplets of one liquid dispersed in another). 'Triphasic' is not a class of dosage form in this scheme, and a solution is a liquid, not a solid.

Answer: C

Powders for external use are dusting powders.

Dusting powders are fine, free-flowing powders applied to the skin, for example as antiseptic, antifungal or absorbent powders. They must be very finely sifted, and those for wounds must be sterile.

Divided powders are separate single doses wrapped in papers, taken by mouth. Effervescent powders are dissolved in water and drunk. Bulk powders are supplied in a single container for the patient to measure, and the term is not specific to external use the way dusting powders are.

Answer: A

The inscription contains the name and quantity of the ingredients.

The inscription is the main body of a prescription. The parts of a prescription are:

• superscription, the symbol Rx;
• inscription, the names and quantities of the ingredients;
• subscription, directions to the pharmacist on how to prepare the medicine;
• signatura, directions to the patient;
• the prescriber's signature.

The patient's name and age come in the heading of the prescription, and the doctor's signature is a separate part at the end.

Answer: A

Double decomposition is a chemical incompatibility.

In double decomposition two salts exchange ions and form a new, often insoluble compound that precipitates. A chemical reaction between ingredients changes the product, so it is a chemical incompatibility, like oxidation, hydrolysis or a change of colour.

Physical incompatibility involves no reaction: immiscible liquids, insoluble drugs, or mixtures that liquefy. Therapeutic incompatibility is a problem with the prescribing, such as antagonistic drugs or an overdose. 'Biological' is not one of the classes of incompatibility.

Answer: A

A solute needing less than 1 part of solvent for 1 part of solute is very soluble.

The pharmacopoeial descriptive terms, in parts of solvent needed for 1 part of solute:

So freely soluble, soluble and slightly soluble all need at least 1 part of solvent, and progressively more.