NAPLEX Quiz: Nonsterile Preparations

What this quiz covers

This quiz focuses on Nonsterile Preparations, giving you a quick way to practice the rules, question types, and explanations that matter most for NAPLEX.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. Store at room temperature and discard after 90 days because levetiracetam is chemically stable in any aqueous vehicle
2. Shake well before each dose and measure using an oral syringe (not a household teaspoon) to ensure accurate dosing (correct answer)
3. Crush the tablets directly into the dispensing bottle, add vehicle to volume, and do not triturate to minimize air incorporation
4. Refrigerate and discard after 24 hours because compounded aqueous suspensions must always have a 1-day beyond-use date

Explanation: This question tests knowledge of proper counseling for compounded oral suspensions, particularly regarding administration technique and accuracy. The patient is a 4-year-old child with epilepsy who requires a dye-free levetiracetam suspension due to an FD&C Red No. 40 allergy. The correct answer (B) emphasizes shaking well before each dose and using an oral syringe for accurate measurement, which is critical for antiepileptic medications where consistent dosing prevents breakthrough seizures. Option A is incorrect because levetiracetam suspensions typically require refrigeration and have shorter beyond-use dates than 90 days. Option C describes poor technique that would result in non-uniform distribution and inaccurate dosing. Option D incorrectly states a 24-hour beyond-use date, which is far too conservative for most aqueous oral preparations. The key counseling pearl is that proper administration technique (shaking and accurate measurement) is essential for therapeutic success with compounded suspensions, especially for critical medications like antiepileptics.

Question 2

1. Compounding with an alkaline vehicle (e.g., sodium bicarbonate-containing) to improve stability of omeprazole in aqueous media
2. Packaging in a tight, light-resistant container and recommending refrigeration if supported by the formulation
3. Preparing the suspension using an acidic vehicle (e.g., citrus-flavored acidic syrup) that can accelerate omeprazole degradation (correct answer)
4. Minimizing exposure to moisture and light during preparation and labeling with an appropriate beyond-use date

Explanation: This question tests knowledge of pH considerations for acid-labile drug stability in oral liquids. The elderly patient with dysphagia needs omeprazole suspension, which is highly acid-labile. The correct answer (C) identifies using an acidic vehicle as the critical error, as omeprazole rapidly degrades in acidic conditions, losing potency. Option A's alkaline vehicle (like sodium bicarbonate-containing) correctly protects omeprazole from acid degradation. Option B's proper packaging and refrigeration enhance stability. Option D's moisture and light protection during preparation are appropriate precautions. The pharmaceutical principle is that acid-labile drugs like proton pump inhibitors require alkaline vehicles for stability in aqueous preparations, making vehicle pH selection critical for maintaining therapeutic efficacy.

Question 3

1. Levigation method: triturate powders, levigate with a small amount of propylene glycol, then incorporate into an oil-in-water cream base by geometric dilution; package in a light-resistant container (correct answer)
2. Fusion method: melt all ingredients together at $80^{\circ}\text{C}$, stir until uniform, and pour into a jar while hot
3. Direct addition: add the powders to the cream base without levigation and mix briefly to avoid over-aeration
4. Prepare as an aqueous gel using purified water only (no base), because creams increase irritation compared with water-based products

Explanation: This question evaluates understanding of proper compounding techniques for topical creams containing multiple active ingredients. The patient has melasma and sensitive skin, requiring a triple-combination cream with hydroquinone, tretinoin, and fluocinolone acetonide. The correct answer (A) describes the levigation method with geometric dilution, which ensures uniform distribution of powders in the cream base and minimizes irritation through proper incorporation technique. Option B's fusion method at 80°C would degrade the heat-sensitive tretinoin. Option C's direct addition without levigation would result in gritty texture and poor drug distribution. Option D incorrectly suggests using only water without a base, which would not provide proper drug delivery or stability. The compounding pearl is that levigation with a small amount of compatible liquid (like propylene glycol) before geometric dilution ensures smooth, uniform topical preparations, and light-resistant packaging protects photosensitive ingredients like tretinoin.

Question 4

1. Crushing tablets and allowing the powder to sit exposed to humidity overnight before adding vehicle (correct answer)
2. Using an oral suspending vehicle and transferring to a tight, light-resistant container
3. Rinsing the mortar with small portions of vehicle and adding rinses to the final preparation to minimize drug loss
4. Labeling 'Shake well' to ensure dose uniformity before administration

Explanation: This question identifies compounding errors affecting clonidine suspension stability. The pediatric patient needs clonidine suspension for bedtime administration, compounded from tablets. The correct answer (A) identifies exposing crushed tablet powder to humidity overnight as a critical error, as moisture exposure can cause drug degradation and alter physical properties before vehicle addition. Option B's proper container selection protects the finished product. Option C's mortar rinsing technique minimizes drug loss and ensures accurate concentration. Option D's shake well labeling ensures dose uniformity. The key principle is that drug powders should be protected from environmental moisture during compounding, as premature exposure can cause degradation, especially for moisture-sensitive drugs like clonidine.

Question 5

1. Mix 1 part of 0.05% ointment with 1 part of plain ointment base using geometric dilution until uniform (correct answer)
2. Mix 1 part of 0.05% ointment with 3 parts of plain ointment base to achieve 0.025%
3. Add purified water to 0.05% ointment until the final concentration is 0.025%, then homogenize
4. Heat the 0.05% ointment to boiling and evaporate half the base to concentrate it to 0.025%

Explanation: This question assesses understanding of dilution calculations for topical corticosteroid preparations. The patient needs clobetasol 0.025% ointment, diluted from the available 0.05% strength for chronic hand eczema. The correct answer (A) uses equal parts (1:1 ratio) of 0.05% ointment and plain base, which mathematically yields 0.025% concentration (0.05% ÷ 2 = 0.025%). Option B's 1:3 ratio would yield 0.0125% (0.05% ÷ 4), which is too dilute. Option C incorrectly suggests adding water to an ointment, which would destabilize the oleaginous base. Option D's heating method is dangerous and would not achieve the desired concentration. The dilution principle for percentage strengths is: C1V1 = C2V2, and when mixing equal volumes of drug-containing base with plain base, the concentration is halved.

Question 6

1. Packaging the suspension in an amber bottle to reduce light exposure
2. Assigning a beyond-use date consistent with USP guidance for water-containing oral formulations when no stability data are available
3. Using tap water as the sole vehicle and omitting a structured suspending agent, leading to caking and non-uniform dosing (correct answer)
4. Using geometric dilution to incorporate the capsule contents into a portion of vehicle before bringing to final volume

Explanation: This question tests identification of compounding errors that compromise suspension stability. The pediatric patient needs nitrofurantoin suspension for UTI treatment, compounded from capsules. The correct answer (C) identifies using tap water without a structured suspending agent as the critical error, leading to rapid settling, caking, and non-uniform dosing of this antimicrobial. Option A's amber packaging protects from light degradation. Option B's USP-compliant beyond-use dating ensures safety. Option D's geometric dilution technique ensures proper drug distribution. The key concept is that suspensions require appropriate suspending vehicles (not just water) to maintain uniform drug distribution throughout the beyond-use period, ensuring each dose contains the intended amount of medication for effective antimicrobial therapy.

Question 7

1. A small amount of a commercially available oral flavor concentrate (e.g., cherry) compatible with aqueous solutions (correct answer)
2. An alcohol-based peppermint essential oil in a large amount to mask taste, regardless of patient sensitivity
3. Calcium carbonate powder to reduce salty taste by neutralization
4. Sucrose crystals added directly without dissolving, to create a sweetened suspension-like product

Explanation: This question tests knowledge of flavoring aqueous oral solutions to improve palatability while maintaining pharmaceutical elegance. The elderly patient with heart failure finds potassium chloride's salty taste nauseating, which affects adherence to this important electrolyte replacement therapy. The correct answer (A) recommends using a small amount of commercially available oral flavor concentrate compatible with aqueous solutions, which effectively masks unpleasant tastes without compromising the solution's properties. Option B's alcohol-based peppermint oil could cause irritation and is inappropriate for elderly patients. Option C's calcium carbonate would create chemical incompatibility and precipitation with potassium chloride. Option D's undissolved sucrose crystals would convert the solution to a suspension, changing the dosage form. The key principle is that flavoring agents for oral solutions must be water-compatible, used in appropriate concentrations, and not alter the physical or chemical properties of the preparation.

Question 8

1. Use lactose monohydrate as the diluent because it improves powder flow and is present in most levothyroxine products
2. Use a lactose-free filler such as microcrystalline cellulose and consider adding a small amount of colloidal silicon dioxide to improve uniformity (correct answer)
3. Increase the levothyroxine strength to 100 mcg per capsule to compensate for lack of lactose and potential reduced absorption
4. Compound as a flavored aqueous solution without preservatives to avoid excipients entirely and assign a 90-day beyond-use date

Explanation: This question evaluates formulation adjustments for patients with excipient allergies, specifically lactose intolerance in levothyroxine capsules. The patient has severe lactose allergy and reacts to commercial tablets containing lactose as a filler. The correct answer (B) recommends using lactose-free fillers like microcrystalline cellulose with colloidal silicon dioxide to improve powder flow and ensure content uniformity in these low-dose capsules. Option A incorrectly suggests using lactose, which would trigger the patient's allergy. Option C's dose adjustment is inappropriate and dangerous, as thyroid hormone requires precise dosing. Option D's aqueous solution would be unstable and the 90-day beyond-use date is incorrect for preservative-free aqueous preparations. The compounding principle is that excipient selection must consider patient allergies while maintaining proper pharmaceutical properties, and flow agents like silicon dioxide are crucial for uniform distribution of potent drugs in capsules.

Question 9

1. Triturate tablets to a fine powder, levigate with a small amount of vehicle to form a smooth paste, then geometrically add vehicle and q.s. to final volume (correct answer)
2. Place intact tablets into the dispensing bottle, add vehicle to volume, and allow to dissolve without shaking
3. Dissolve tablets in hot water, boil for 10 minutes, then cool and q.s. to volume
4. Prepare as an oil-based solution to prevent microbial growth, without any suspending agent

Explanation: This question tests appropriate compounding procedures for oral suspensions from tablets, including trituration and geometric dilution. The key compounding factor is baclofen's need for fine dispersion to ensure dose uniformity. Option A is the best choice as trituration, levigation, and geometric addition create a stable, uniform suspension. Option B is incorrect without agitation, leading to incomplete dispersion; option C is suboptimal as heat can degrade baclofen; option D is wrong as oil-based without suspending agents risks separation. Distractors highlight improper techniques. A compounding pearl is to always triturate tablets finely before suspension to minimize particle size variability. For pediatric formulations, calibrate volumes precisely and add flavoring to improve adherence.

Question 10

1. A sweetening agent and a strong masking flavor (for example, bubblegum or cherry) compatible with the suspending vehicle (correct answer)
2. A high concentration of sodium bicarbonate to fully eliminate bitterness by alkalinization regardless of stability
3. A topical-grade wintergreen oil intended for external use to improve taste
4. An alcohol-based flavor extract in a large volume for a pediatric patient without considering alcohol content

Explanation: This question tests flavoring strategies for bitter pediatric oral suspensions to promote adherence. The key patient-specific factor is the 3-year-old child's inability to swallow tablets, requiring a palatable metronidazole suspension. Option A is the best choice as sweeteners with strong masking flavors like bubblegum are compatible and effective for bitterness. Option B is incorrect as sodium bicarbonate may destabilize the drug; option C is suboptimal with topical oils unsafe for ingestion; option D is wrong due to alcohol risks in pediatrics. Distractors pose safety issues. A compounding pearl is to choose child-friendly flavors and avoid alcohol in pediatric formulations. Always counsel on dental hygiene for sweetened medications to prevent caries.

Question 11

1. A compatible sweetener (for example, sucralose) and a flavoring agent selected to match the medication's taste profile (correct answer)
2. A laxative syrup to mask bitterness through increased viscosity regardless of compatibility
3. A topical anesthetic to numb taste buds and improve adherence
4. A large amount of citric acid to make the solution very sour without evaluating drug stability

Explanation: This question tests flavoring methods for bitter oral solutions, focusing on compatible additives for palatability. The key patient-specific factor is the elderly patient's need for adherence to a bitter medication. Option A is the best choice as sweeteners with matched flavors effectively mask bitterness without stability issues. Option B is incorrect with incompatible viscosity changes; option C is suboptimal as anesthetics are unsafe; option D is wrong with excessive acid risking degradation. Distractors pose risks. A compounding pearl is to test flavor compatibility in small batches. Consider patient preferences and drug interactions when enhancing taste for chronic therapies.

Question 12

1. Using geometric dilution to incorporate the active into the cream base
2. Selecting a cream base compatible with the active ingredient and intended site of use
3. Adding excessive water to thin the cream, potentially destabilizing the emulsion and altering preservative effectiveness (correct answer)
4. Packaging in a tight container and labeling for external use

Explanation: This question tests identification of compounding errors in topical creams, focusing on emulsion stability and preservative efficacy. The key compounding factor is metronidazole's compatibility with cream bases, avoiding dilution that destabilizes. Option C is the best choice as excessive water breaks the emulsion and dilutes preservatives. Option A is not an error but correct dilution; option B is standard selection; option D is appropriate packaging. Distractors are proper steps. A compounding pearl is to avoid altering water content in preserved creams to maintain antimicrobial activity. For custom topicals, verify base-drug compatibility and assign BUDs per USP guidelines.

Question 13

1. A compatible flavor such as grape or cherry plus a sweetener, considering potential tooth staining counseling (correct answer)
2. Activated charcoal to bind the metallic taste in the bottle
3. Sodium hydroxide to eliminate metallic taste by raising pH substantially
4. A large volume of peppermint essential oil regardless of oral safety limits

Explanation: This question tests flavoring approaches for metallic-tasting oral solutions to improve compliance. The key patient-specific factor is the elderly patient's missed doses due to ferrous sulfate's metallic taste. Option A is the best choice as compatible flavors like grape with sweeteners mask metallic notes and counsel on staining. Option B is incorrect as charcoal binds the drug; option C is suboptimal with pH changes risking instability; option D is wrong due to essential oil toxicity. Distractors introduce incompatibilities. A compounding pearl is to use fruit flavors for metallic tastes and warn about dental effects. Evaluate patient age and comorbidities when selecting flavoring agents for long-term use.

Question 14

1. Using an oral suspending vehicle and transferring with multiple mortar rinses to minimize loss
2. Leaving the compounded suspension in an open beaker overnight before bottling to allow air bubbles to dissipate (correct answer)
3. Using geometric dilution when incorporating the triturated powder into the vehicle
4. Dispensing in an amber bottle and labeling "Shake well"

Explanation: This question tests identification of compounding errors in preparing oral suspensions from tablets, focusing on techniques that affect stability. The key compounding factor is spironolactone's hydrophobicity, requiring proper dispersion for uniformity. Option B is the best choice as leaving the suspension in an open beaker allows evaporation and contamination, compromising stability. Option A is not an error but a correct technique to minimize loss; option C is standard geometric dilution; option D is appropriate packaging and labeling. Distractors represent proper steps, highlighting the error in exposure. A compounding pearl is to minimize air exposure during compounding to prevent oxidation and microbial ingress. For suspensions, use a closed system and assign BUDs based on the drug's sensitivity to light, air, and temperature.

Question 15

1. Proceed as written because ketoprofen is not related to aspirin and does not cross-react
2. Substitute ketoprofen with diclofenac to avoid aspirin cross-reactivity
3. Clarify with the prescriber because ketoprofen is an NSAID and may pose risk in aspirin-allergic patients; consider a non-NSAID alternative (correct answer)
4. Add sodium salicylate to desensitize the patient to aspirin-related compounds

Explanation: This question tests formulation adjustments for compounded topicals in patients with allergies, focusing on NSAID cross-reactivity. The key patient-specific factor is the aspirin allergy (urticaria), which may extend to other NSAIDs like ketoprofen. Option C is the best choice as it prompts clarification with the prescriber due to potential cross-reactivity risks, suggesting safer non-NSAID alternatives. Option A is incorrect as ketoprofen can cross-react with aspirin; option B is suboptimal without prescriber input and diclofenac also poses risks; option D is wrong as adding salicylate could worsen the allergy. Distractors ignore allergy safety protocols. A compounding pearl is to screen for cross-reactive ingredients and consult prescribers for alternatives in allergic patients. Use a framework: identify allergen, evaluate formulation components, and prioritize patient safety over proceeding as written.

Question 16

1. Selecting an oral suspending vehicle and shaking vigorously to ensure uniformity before dispensing
2. Using a mortar and pestle to reduce tablets to a fine powder before adding vehicle
3. Assigning a beyond-use date of 90 days for a water-containing oral suspension stored at room temperature (correct answer)
4. Labeling the bottle with "Shake well" and appropriate dose measuring device instructions

Explanation: This question tests identification of compounding errors in oral suspensions, particularly beyond-use date assignment for stability and safety. The key compounding factor is preparing clonidine suspension from tablets for a child unable to swallow solids. Option C is the best choice as assigning a 90-day beyond-use date at room temperature exceeds USP <795> guidelines for aqueous orals, risking microbial growth and degradation. Option A is not an error but proper vehicle selection and shaking; option B is a standard trituration technique; option D is appropriate labeling for uniformity and dosing accuracy. Distractors like A, B, and D are correct practices, emphasizing the need to spot BUD errors. A compounding pearl is that nonsterile aqueous oral suspensions have a maximum 14-day refrigerated BUD unless extended by testing. Use a decision framework: assess water content, storage temperature, and drug stability data before assigning BUDs.

Question 17

1. Use a lanolin-containing absorption base to improve penetration and proceed
2. Select a lanolin-free ointment base and compound hydrocortisone into that base to avoid the allergen (correct answer)
3. Add lanolin at a lower concentration to reduce the likelihood of allergy
4. Change to a topical solution dosage form without consulting the prescriber

Explanation: This question tests formulation adjustments for compounded ointments in patients with allergies, focusing on base selection. The key patient-specific factor is the lanolin allergy (rash), common in atopic dermatitis patients. Option B is the best choice as selecting a lanolin-free base avoids the allergen while incorporating hydrocortisone effectively. Option A is incorrect as lanolin-containing bases would trigger the allergy; option C is suboptimal with unnecessary lanolin; option D is wrong without prescriber consultation. Distractors promote allergen exposure. A compounding pearl is to choose hypoallergenic bases for sensitive skin conditions. Use a decision framework: screen patient allergies, select alternative ingredients, and document rationale for changes.

Question 18

1. A sweetening agent and a compatible flavor such as cherry or grape, per manufacturer flavoring recommendations (correct answer)
2. Mineral oil to mask taste by coating the mouth
3. Sodium chloride to balance electrolytes and reduce bitterness
4. Crushed aspirin powder to provide a mint-like taste

Explanation: This question tests flavoring strategies for oral solutions to improve adherence, focusing on masking salty or bitter tastes without altering efficacy. The key patient-specific factor is the elderly patient's poor adherence to potassium chloride due to its unpleasant taste. Option A is the best choice as sweetening agents combined with compatible flavors like cherry effectively mask bitterness per established flavoring guidelines. Option B is incorrect as mineral oil can interfere with absorption and is not suitable for oral use; option C is suboptimal because sodium chloride would exacerbate saltiness; option D is wrong as aspirin introduces unnecessary risks and does not provide mint taste. Distractors represent incompatible or unsafe additives. A transferable pearl is to select flavors based on the drug's taste profile, such as fruit flavors for salty medications. Always check for compatibility and avoid allergens when flavoring for chronic conditions in the elderly.

Question 19

1. Using a lotion base compatible with the active ingredient and mixing until uniform
2. Calculating the required amount of pramoxine based on final volume and desired concentration
3. Using a container that is not tight and allows evaporation of volatile components, changing concentration over time (correct answer)
4. Labeling "For external use only" and providing application directions

Explanation: This question tests identification of compounding errors in topical lotions, emphasizing container selection for stability. The key compounding factor is pramoxine's volatility in lotions, requiring tight containers to prevent evaporation. Option C is the best choice as non-tight containers allow evaporation, altering concentration. Option A is not an error but correct mixing; option B is standard calculation; option D is appropriate labeling. Distractors represent proper practices. A compounding pearl is to use airtight containers for volatile topicals to maintain integrity. For lotions, ensure emulsion stability and assign BUDs based on water content and preservatives.

Question 20

1. A compatible flavoring agent (for example, citrus) and, if needed, a small amount of acidulant per flavor system guidance (correct answer)
2. Calcium carbonate to neutralize taste and thicken the solution
3. An anise oil essential oil at high concentration to fully mask taste regardless of compatibility
4. Propylene glycol in large volume to reduce perceived sweetness by dilution

Explanation: This question tests flavoring techniques for overly sweet oral solutions to enhance palatability without compromising stability. The key patient-specific factor is the elderly patient's refusal of lactulose due to excessive sweetness. Option A is the best choice as compatible flavors like citrus with acidulants reduce perceived sweetness per flavoring guidelines. Option B is incorrect as calcium carbonate may cause incompatibilities; option C is suboptimal with high essential oil risks; option D is wrong as propylene glycol dilution could alter osmolarity. Distractors introduce unsafe or incompatible agents. A compounding pearl is to balance flavors with the drug's profile, using acidulants for sweet tastes. Always evaluate excipient compatibility and patient age when flavoring chronic therapies.