AuthorisedHuman Pharmacology (Phase I)- Bioequivalence StudyInterventional

An open label, balanced, randomized, single dose, two-treatment, two period, two-sequence, crossover, bioequivalence study comparing Fexofenadine HCl and Pseudoephedrine HCl Extended Release Tablet 180 mg/240 mg, Manufactured by: Sun Pharmaceutical Industries Limited, India with Allegra-D® 24 HR (Fexofenadine HCl and Pseudoephedrine HCl Extended Release Tablets 180 mg + 240 mg) tablets, Distributed by: Chattem Inc., a Sanofi Company Chattanooga, TN 37409-0219, USA, in healthy, adult, human participants under fed conditions.

This study compares a new version of an allergy tablet with the established brand-name medicine, Allegra-D 24 HR. Both tablets combine two medicines: fexofenadine, an antihistamine that eases runny noses and itchy eyes, and pseudoephedrine, a decongestant that clears blocked sinuses. Together, they treat seasonal allergic rhinitis, commonly known as hay fever. The goal is to show 'bioequivalence'. This means proving that the generic tablet releases the same amount of medicine into the bloodstream at the same speed as the original brand. Healthy adult volunteers will take part. Everyone receives a single dose of each tablet on two separate occasions after eating food, with a break in between. Blood samples will be taken to measure and compare medicine levels. Generic medicines are important because they offer safe, effective, and lower-cost treatment options for patients and healthcare services like the NHS.

At a glance

Status

Authorised

Phase

Human Pharmacology (Phase I)- Bioequivalence Study

Sponsor

Sun Pharmaceutical Industries Limited

Enrolment target

Start

01 Jul 2026

Seasonal allergic rhinitis

What is this study about?

Seasonal allergic rhinitis, better known as hay fever, affects millions of people across the UK every year. It causes sneezing, itchy eyes, a runny nose, and a blocked, stuffy head. To manage these symptoms, doctors often suggest a combination of an antihistamine to calm the allergic reaction and a decongestant to relieve nasal swelling. This study looks at a tablet that contains both: fexofenadine and pseudoephedrine, designed to work over a full 24 hours.

The research compares a new generic version made by Sun Pharma with the well-known branded version, Allegra-D 24 HR. When a patent on an original medicine expires, other companies can produce generic copies. However, before a generic medicine can be approved for public use, scientists must prove that it delivers the exact same amount of active ingredient into the body as the original brand. This is known as a bioequivalence study.

In this trial, healthy volunteers will take each tablet once after eating a meal. Testing the medicine with food is important because meals can change how quickly medicines are absorbed into the stomach and bloodstream. By confirming that both tablets perform identically, this study helps ensure that patients have access to safe, reliable, and more affordable allergy treatments in the future.

Key takeaways

Compares a generic allergy tablet to the branded version, Allegra-D 24 HR.
Aims to prove both tablets deliver the same amount of medicine into the body.
Open to healthy adult volunteers aged 18 and older.
Involves taking a single dose twice, after eating a meal, with a rest period in between.
Requires blood samples to track medicine levels over time.

Who may be eligible?

This study is looking for healthy adult volunteers aged 18 and older. Both men and women can apply. Because this is an early-stage study designed simply to test how the body absorbs the medicine, researchers need healthy people rather than patients currently suffering from severe medical conditions.

To be considered healthy, volunteers will need to undergo standard medical checks, which usually include a physical examination, heart rhythm checks (an ECG), and routine blood and urine tests. People taking regular prescription medicines, or those with underlying long-term health issues affecting the heart, liver, or kidneys, will likely not be able to join.

Volunteers will also need to be able to eat a set meal before taking the tablet, as the study specifically tests the medicine under 'fed' conditions. Pregnant or breastfeeding women are typically excluded from Phase 1 studies to protect the safety of the mother and baby.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

I am at least 18 years old.
I consider myself to be in good overall health.
I do not have long-term heart, kidney, or liver conditions.
I am not currently taking regular prescription medicines.
I am comfortable having standard blood tests and eating a set meal.
I am not currently pregnant or breastfeeding.

Answer every question to see your result.

What does participation involve?

Taking part involves joining a 'crossover' study split into two separate treatment periods. In one period, you will receive a single tablet of the new generic medicine, and in the other, you will receive a single tablet of the original Allegra-D. Both doses are taken by mouth with water shortly after eating a standard meal.

You will need to stay at a clinical research unit for a short period during each treatment visit. Across your stay, nursing staff will take small blood samples at regular time points over 24 hours or longer. These samples track how the medicine enters and leaves your body. Between the two periods, there will be a 'washout' break of at least a week to ensure the first dose has completely cleared from your system.

Before taking any medicine, you will attend a screening visit to check your general health. A final check-up will take place at the end of the trial to ensure you feel well. In total, the study usually takes a few weeks from your initial screening to your final appointment.

Potential risks and benefits

Because you are taking a single dose of medicines that are already widely used, the risk of serious side effects is low. However, you might experience mild, temporary reactions such as a dry mouth, mild headache, drowsiness, or difficulty sleeping due to the decongestant. Having blood samples taken may also cause minor bruising or soreness around the needle site. You will not receive any direct medical benefit from taking part, but your participation helps make affordable medicines available to others. Joining is entirely voluntary, and you are free to leave the study at any time without giving a reason.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

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Unverified
Romania

Common questions

What is a bioequivalence study?

It is a scientific test to prove that a new generic medicine works in the exact same way and releases the same amount of active drug into your body as the original branded version.

Will taking part cure my hay fever?

No. This study only involves taking two single doses to measure blood levels in healthy volunteers. It is not designed to treat long-term allergy symptoms.

Why do I have to eat before taking the tablet?

Food can alter how your stomach absorbs medicines. Testing after a meal checks whether the generic tablet behaves identically to the brand-name version in real-world conditions.

Are blood tests painful?

Having blood taken can feel like a quick pinch and may leave a small bruise, but staff use thin needles or a small temporary tube (cannula) to keep discomfort to a minimum.

Can I leave the study early if I change my mind?

Yes. Participation is completely voluntary. You can withdraw your consent and leave the study at any point without it affecting your future medical care.