Dissolution Testing for Tablets & Capsules – Ensuring Bioavailability and Drug Efficacy

A tablet that doesn't dissolve properly in the stomach is worthless—your patient never receives the active drug. Dissolution testing ensures that tablets and capsules release their active ingredient at the right rate, enabling proper absorption and therapeutic efficacy.

For pharmaceutical manufacturers, dissolution testing is mandatory for CDSCO and FDA approval. Hetero Analytical Solutions LLP conducts dissolution studies following USP, EP, and BP standards, ensuring your products deliver consistent, reliable efficacy.

What is Dissolution Testing?

Dissolution testing measures how quickly and completely a solid dosage form (tablet, capsule) releases its active pharmaceutical ingredient (API) in a simulated body fluid.

Why It Matters:

Drug Efficacy – If a tablet dissolves too slowly, therapeutic levels aren't reached

Patient Safety – Too-rapid dissolution can cause toxicity or side effects

Regulatory Compliance – Required for market approval in all regulated markets

Batch Consistency – Ensures every batch releases drug at the same rate

Without dissolution data, regulators cannot approve your product for market release.

How Dissolution Testing Works

Apparatus USP II (Paddle Method)

The most common dissolution apparatus:

• A tablet or capsule is placed in a vessel containing 900 mL of dissolution medium (simulated digestive fluid at body temperature: 37°C)

• A paddle stirrer rotates at specified RPM, simulating stomach/intestinal movement

• Samples are withdrawn at specific time intervals (15, 30, 45, 60 minutes)

• Each sample is analyzed via HPLC to quantify API concentration

• Results show percentage of drug dissolved at each time point

  
  

Apparatus USP I (Basket Method)

Alternative method used for faster-dissolving products or for certain formulation types.

Dissolution Media

Simulates different body fluid environments:

• 0.1 N HCl (pH 1.2) – Simulates gastric fluid (stomach)

• pH 4.5 Acetate Buffer – Simulates small intestine

• pH 6.8 Phosphate Buffer – Simulates small intestine

• pH 7.5 Phosphate Buffer – Simulates late-stage small intestine

Different formulations require testing in different media per USP/EP guidelines.

Dissolution Specifications & Acceptance Criteria

Typical Tablet Specification: "Not less than 75% dissolved in 30 minutes" (or other time points)

If a tablet shows only 65% dissolved at 30 minutes, the batch FAILS and cannot be released.

Why Strict Limits?

• Too Fast – Drug absorbed too quickly, causing peak blood levels and potential toxicity

• Too Slow – Therapeutic levels not reached, efficacy lost

• Inconsistent – Batch-to-batch variation indicates manufacturing issues

  
  

Dissolution Testing Standards

USP (United States Pharmacopeia)

Apparatus specifications, media composition, sampling methods detailed in USP <711> Dissolution

EP (European Pharmacopoeia)

Similar standards in European Pharmacopoeia 2.2.3

BP (British Pharmacopoeia)

UK/Commonwealth standard aligned with EP

CDSCO Guidelines

Indian regulatory acceptance of USP/EP dissolution methods for market approval

Common Dissolution Scenarios

Immediate-Release Tablet

• Specification: ≥75% in 30 minutes

• Goal: Fast drug absorption for rapid therapeutic effect

• Example: Aspirin, paracetamol

Extended-Release (ER) Tablet

• Specification: 25% in 1 hour, 50% in 4 hours, ≥80% in 12+ hours

• Goal: Sustained drug release over 12-24 hours, reducing dosing frequency

• Example: Metformin ER, atenolol ER

Enteric-Coated Tablet

• Specification: <10% in pH 1.2 (stomach), ≥75% in pH 6.8 (intestine)

• Goal: Bypass stomach, release in intestine to protect API or stomach lining

• Example: Aspirin EC, mesalamine

Industries Using Dissolution Testing

Oral Pharmaceuticals – Tablets, capsules (mandatory for all products)

Nutraceuticals – Dietary supplements claiming bioavailability

OTC Products – Over-the-counter pain relievers, antihistamines

Herbal Formulations – Ayurvedic tablets requiring bioavailability verification

Veterinary Products – Animal tablets and capsules

Why Hetero Analytical for Dissolution Testing

✅ USP/EP Validated Methods – All apparatus and procedures accredited to international standards

✅ NABL Accreditation – Results accepted by CDSCO, USFDA, EMA

✅ Advanced Instrumentation – USP Apparatus I & II, automated sampling systems

✅ HPLC Analysis – Precise API quantification at each time point

✅ Fast Turnaround – Expedited testing for urgent product launches

✅ Regulatory Support – Guidance on specification setting and batch troubleshooting

Real-World Impact

Case Study: ER Tablet Launch

A manufacturer developed an extended-release tablet. Initial in-house dissolution testing showed acceptable results. Hetero Analytical's comprehensive testing revealed inconsistent dissolution at the 4-hour timepoint—batch-to-batch variation of 15%. Root cause: compression force inconsistency. Manufacturing process adjusted, re-testing passed. CDSCO approval granted. Lesson: Detailed dissolution analysis prevents market failures.

Testing Checklist

✅ Product type identified (IR, ER, enteric-coated)

✅ Dissolution medium selected (pH matching product target)

✅ Apparatus confirmed (USP I or II)

✅ Sampling timepoints defined

✅ Specification limits established

✅ HPLC method validated

✅ Batch testing completed

✅ Results within specification

✅ CDSCO/FDA approval obtained

Partner with Hetero Analytical for Dissolution Success

Dissolution testing is non-negotiable for market approval. Hetero Analytical's expertise, NABL accreditation, and validated methods ensure your tablets and capsules meet regulatory requirements and deliver consistent efficacy.

Contact Hetero Analytical Solutions LLP today for dissolution testing and regulatory support.

📍 Hetero Analytical Solutions LLP Changodar, Ahmedabad, Gujarat

📞 +91 98166 18822 🌐 heteroanalytical.com