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Registry Hub
Peer-Reviewed Evidence
HomeDrug RegistryCompareCAPITROL vs ACULAR PRESERVATIVE FREE
Comparative Pharmacology

CAPITROL vs ACULAR PRESERVATIVE FREE Comparison

Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.

Clinical EssentialsPharmacokineticsSpecial PopulationsSafety & MonitoringPregnancy & LactationClinical Insights
Differential Analysis

CAPITROL vs ACULAR PRESERVATIVE FREE

Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.

View CAPITROL Monograph View ACULAR PRESERVATIVE FREE Monograph
CAPITROL
Topical Antimicrobial
Category C
ACULAR PRESERVATIVE FREE
NSAID Ophthalmic
Category C
TL;DR — Key Differences
  • Drug class: CAPITROL is a Topical Antimicrobial; ACULAR PRESERVATIVE FREE is a NSAID Ophthalmic.
  • Half-life: CAPITROL has a half-life of Terminal elimination half-life is 20-40 hours; clinically, steady-state is achieved within 5-7 days.; ACULAR PRESERVATIVE FREE has Terminal elimination half-life is approximately 5-6 hours in adults, but can be prolonged in elderly patients (up to 8-9 hours) and in patients with renal impairment (up to 13-19 hours)..
  • No direct drug-drug interaction has been documented between CAPITROL and ACULAR PRESERVATIVE FREE.
  • Pregnancy: CAPITROL is rated Category C; ACULAR PRESERVATIVE FREE is rated Category C.

Last clinically reviewed: July 2026 · OpiCalc Medical Review Team

Clinical Essentials

CAPITROL
ACULAR PRESERVATIVE FREE
Mechanism of Action
CAPITROL

Ciclopirox is a hydroxypyridine antifungal agent that inhibits the uptake of essential elements and amino acids, disrupts fungal cell membrane integrity, and chelates polyvalent cations (e.g., Fe3+, Al3+), inhibiting metal-dependent enzymes such as cytochromes and catalase.

ACULAR PRESERVATIVE FREE

Ketorolac tromethamine is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX-1 and COX-2) enzymes, thereby reducing prostaglandin synthesis. It produces anti-inflammatory and analgesic effects.

Indications
CAPITROL

Topical treatment of seborrheic dermatitis of the scalp in adults

ACULAR PRESERVATIVE FREE

FDA-approved: Treatment of ocular inflammation and pain following cataract surgery and corneal refractive surgery.,Off-label: Relief of seasonal allergic conjunctivitis symptoms, management of cystoid macular edema, and treatment of postoperative inflammation in other ocular procedures.

Standard Dosing
CAPITROL

Apply 1 m L of 1% shampoo twice weekly for 4 weeks, then weekly for maintenance. Use on wet hair, lather for 2-3 minutes, rinse thoroughly.

ACULAR PRESERVATIVE FREE

1 drop into affected eye(s) four times daily (every 6 hours). Instill into conjunctival sac. Shake well before use.

Direct Interaction
CAPITROL
No Direct Interaction
ACULAR PRESERVATIVE FREE
No Direct Interaction

Pharmacokinetics

CAPITROL
ACULAR PRESERVATIVE FREE
Half-Life
CAPITROL

Terminal elimination half-life is 20-40 hours; clinically, steady-state is achieved within 5-7 days.

ACULAR PRESERVATIVE FREE

Terminal elimination half-life is approximately 5-6 hours in adults, but can be prolonged in elderly patients (up to 8-9 hours) and in patients with renal impairment (up to 13-19 hours).

Metabolism
CAPITROL

Ciclopirox is primarily metabolized via glucuronidation, with less than 2% excreted unchanged in urine. The major metabolite is ciclopirox glucuronide.

ACULAR PRESERVATIVE FREE

Ketorolac undergoes hepatic metabolism via hydroxylation and conjugation (glucuronidation) to inactive metabolites. It is primarily metabolized by CYP2D6 and CYP3A4 isoenzymes, with renal excretion of metabolites and unchanged drug.

Excretion
CAPITROL

Primarily renal (approximately 60-70% as unchanged drug); biliary/fecal elimination accounts for about 20-30%.

ACULAR PRESERVATIVE FREE

Primarily renal excretion of metabolites and unchanged drug; approximately 80% of a dose is excreted in urine as ketorolac and its hydroxy metabolites, with about 6% excreted in feces.

Protein Binding
CAPITROL

>99% bound to albumin and alpha-1-acid glycoprotein.

ACULAR PRESERVATIVE FREE

99% bound to plasma proteins, primarily albumin.

VD (L/kg)
CAPITROL

0.3 L/kg; indicates distribution primarily into extracellular fluid.

ACULAR PRESERVATIVE FREE

0.15-0.25 L/kg after oral administration; for ophthalmic use, systemic absorption is minimal, so Vd is not clinically meaningful.

Bioavailability
CAPITROL

Oral: 70-80%; Topical: approximately 5-10%.

ACULAR PRESERVATIVE FREE

Ophthalmic administration: Systemic bioavailability is approximately 0.5-1% after ocular instillation due to low corneal penetration and rapid clearance; oral bioavailability is 100%.

Special Populations

CAPITROL
ACULAR PRESERVATIVE FREE
Renal Adjustments
CAPITROL

No adjustment required as systemic absorption is negligible.

ACULAR PRESERVATIVE FREE

No dosage adjustment required for renal impairment. Drug is minimally absorbed systemically.

Hepatic Adjustments
CAPITROL

No adjustment required as systemic absorption is negligible.

ACULAR PRESERVATIVE FREE

No dosage adjustment required for hepatic impairment. Drug is minimally absorbed systemically.

Pediatric Dosing
CAPITROL

Safety and efficacy not established in children under 12 years; use same as adult for ages 12 and above.

ACULAR PRESERVATIVE FREE

Children ≥3 years: 1 drop into affected eye(s) four times daily. Safety and efficacy in children <3 years not established.

Geriatric Dosing
CAPITROL

No specific dose adjustment; caution with dry or aged skin due to potential irritation.

ACULAR PRESERVATIVE FREE

No specific dosage adjustment required. Use same dose as adults; monitor for tolerability.

Safety & Monitoring

CAPITROL
ACULAR PRESERVATIVE FREE
Black Box Warnings
CAPITROL
FDA Black Box Warning

None.

ACULAR PRESERVATIVE FREE
FDA Black Box Warning

NSAIDs may increase the risk of serious cardiovascular events (e.g., myocardial infarction, stroke) and gastrointestinal events (e.g., bleeding, ulceration, perforation). However, due to low systemic absorption with ophthalmic use, this boxed warning is less clinically relevant but still applies.

Warnings/Precautions
CAPITROL

Avoid contact with eyes,If irritation or sensitization occurs, discontinue use,Not for oral, ophthalmic, or intravaginal use

ACULAR PRESERVATIVE FREE

Use with caution in patients with compromised ocular surface, history of herpes simplex keratitis, bleeding tendencies, or those on anticoagulants. Prolonged use may delay wound healing. Monitor for signs of corneal epithelial breakdown or infection.

Contraindications
CAPITROL

Hypersensitivity to ciclopirox or any component of the formulation

ACULAR PRESERVATIVE FREE

Hypersensitivity to ketorolac or any component of the formulation; patients with active ocular infection or advanced dry eye; history of asthma, urticaria, or allergic-type reactions to aspirin or other NSAIDs.

Adverse Reactions
CAPITROL
Data Pending
ACULAR PRESERVATIVE FREE
Data Pending
Food Interactions
CAPITROL

No known food interactions when applied topically. However, avoid applying immediately before consuming food to minimize accidental ingestion.

ACULAR PRESERVATIVE FREE

No known food interactions. No dietary restrictions required.

Pregnancy & Lactation

CAPITROL
ACULAR PRESERVATIVE FREE
Teratogenic Risk
CAPITROL

No adequate human studies; animal studies not available. Only minimal systemic absorption occurs with topical scalp application; theoretical risk low. First trimester: unlikely to cause harm due to negligible absorption; however, avoid elective use. Second and third trimesters: no known risks.

ACULAR PRESERVATIVE FREE

FDA Pregnancy Category C. No adequate studies in pregnant women. In animal studies, ketorolac tromethamine (active ingredient) was not teratogenic in rats or rabbits at doses up to 1.5-3 times the human exposure. However, because NSAIDs can cause premature closure of the ductus arteriosus and oligohydramnios in the third trimester, use is contraindicated after 30 weeks gestation. In first and second trimesters, use only if potential benefit justifies potential fetal risk.

Lactation Summary
CAPITROL

Minimal systemic absorption; expected to be safe during breastfeeding. M/P ratio not determined. Avoid application to breast area.

ACULAR PRESERVATIVE FREE

Ketorolac is excreted in human milk following oral administration. After a single intramuscular dose of 10 mg, the milk-to-plasma (M/P) ratio was 0.037. Low levels are expected in breastmilk; however, due to potential adverse effects of NSAIDs on neonates, caution is advised. Use is generally avoided in nursing mothers, especially with premature infants or those with thrombocytopenia or renal impairment.

Pregnancy Dosing
CAPITROL

No dose adjustment required; topical use only.

ACULAR PRESERVATIVE FREE

No specific pharmacokinetic studies in pregnancy. Dosing should be at the lowest effective dose for the shortest duration. Avoid use after 30 weeks gestation. No adjustment for first or second trimester unless renal function changes.

Maternal Safety Status
CAPITROL
Category C
ACULAR PRESERVATIVE FREE
Category C

Clinical Insights

CAPITROL
ACULAR PRESERVATIVE FREE
Clinical Pearls
CAPITROL

Capitrol (chloroxine) is a topical antibacterial shampoo indicated for dandruff and seborrheic dermatitis. It is generally used twice weekly for 2 weeks, then as needed. Avoid contact with eyes and mucous membranes. Discontinue if local irritation or allergic reaction occurs.

ACULAR PRESERVATIVE FREE

ACULAR (ketorolac tromethamine ophthalmic solution) is an NSAID for ocular use. Preservative-free formulation is indicated for single-use to avoid corneal toxicity. Apply with caution in patients with bleeding disorders or those on anticoagulants due to risk of ocular bleeding. Prolonged use may delay corneal healing. Monitor for signs of keratitis or conjunctival hyperemia.

Patient Counseling
CAPITROL

Use exactly as directed; do not use more often than prescribed.,Wet hair and scalp thoroughly before applying shampoo.,Massage into scalp and leave on for 2-3 minutes before rinsing.,Avoid contact with eyes; if occurs, rinse thoroughly with water.,Use caution to avoid staining of clothing or jewelry; rinse shampoo off completely.,Consult healthcare provider if condition persists or worsens after 2 weeks.,Inform doctor if you are pregnant, planning to become pregnant, or breastfeeding.

ACULAR PRESERVATIVE FREE

Use exactly as prescribed; do not touch the dropper tip to any surface to avoid contamination.,Each single-use vial is for one dose only; discard after use to prevent infection.,Remove contact lenses before instillation and wait 10 minutes before reinserting.,Do not drive or operate machinery if vision is blurry after application.,Report eye pain, increased redness, or vision changes to your doctor immediately.

Safety Verification

Known Interactions

CAPITROL Risks

No interactions on record

ACULAR PRESERVATIVE FREE Risks

No interactions on record

Compare Alternatives

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ACULAR PRESERVATIVE FREE vs NEVANACNSAID Ophthalmic
Clinical Q&A

Frequently Asked Questions

Common clinical questions about CAPITROL vs ACULAR PRESERVATIVE FREE, answered by our medical review team.

1. What is the main difference between CAPITROL and ACULAR PRESERVATIVE FREE?

CAPITROL is a Topical Antimicrobial that works by Ciclopirox is a hydroxypyridine antifungal agent that inhibits the uptake of essential elements and amino acids, disrupts fungal cell membrane integrity, and chelates polyvalent cations (e.g., Fe3+, Al3+), inhibiting metal-dependent enzymes such as cytochromes and catalase.. ACULAR PRESERVATIVE FREE is a NSAID Ophthalmic that works by Ketorolac tromethamine is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX-1 and COX-2) enzymes, thereby reducing prostaglandin synthesis. It produces anti-inflammatory and analgesic effects.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.

2. Which is stronger: CAPITROL or ACULAR PRESERVATIVE FREE?

Potency comparisons between CAPITROL and ACULAR PRESERVATIVE FREE depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.

3. What is the standard dosing for CAPITROL vs ACULAR PRESERVATIVE FREE?

The standard adult dose of CAPITROL is: Apply 1 m L of 1% shampoo twice weekly for 4 weeks, then weekly for maintenance. Use on wet hair, lather for 2-3 minutes, rinse thoroughly.. The standard adult dose of ACULAR PRESERVATIVE FREE is: 1 drop into affected eye(s) four times daily (every 6 hours). Instill into conjunctival sac. Shake well before use.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.

4. Can you take CAPITROL and ACULAR PRESERVATIVE FREE together?

No direct drug-drug interaction has been formally documented between CAPITROL and ACULAR PRESERVATIVE FREE in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.

5. Are CAPITROL and ACULAR PRESERVATIVE FREE safe during pregnancy?

The maternal-fetal safety profiles differ. CAPITROL is classified as Category C. No adequate human studies; animal studies not available. Only minimal systemic absorption occurs with topical scalp application; theoretical risk low. First trimester: unlikely to . ACULAR PRESERVATIVE FREE is classified as Category C. FDA Pregnancy Category C. No adequate studies in pregnant women. In animal studies, ketorolac tromethamine (active ingredient) was not teratogenic in rats or rabbits at doses up to. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.