List of Excipients in Branded Drug DARUNAVIR 600 AND 800 MG

Generic Drugs Containing DARUNAVIR 600 AND 800 MG

Company	Ingredient	NDC	Excipient
Bryant Ranch Prepack	darunavir	63629-5686	CELLULOSE, MICROCRYSTALLINE
Bryant Ranch Prepack	darunavir	63629-5686	CROSPOVIDONE
Bryant Ranch Prepack	darunavir	63629-5686	MAGNESIUM STEARATE
Bryant Ranch Prepack	darunavir	63629-5686	POLYETHYLENE GLYCOL 3350
Bryant Ranch Prepack	darunavir	63629-5686	POLYVINYL ALCOHOL
Bryant Ranch Prepack	darunavir	63629-5686	SILICON DIOXIDE
Bryant Ranch Prepack	darunavir	63629-5686	TALC

What are the Most Frequently-Used Excipients in DARUNAVIR 600 AND 800 MG?

# Of NDCs	Excipient
2	CELLULOSE, MICROCRYSTALLINE
2	CROSPOVIDONE
1	FD&C YELLOW NO. 6
2	MAGNESIUM STEARATE
2	POLYETHYLENE GLYCOL 3350
2	POLYVINYL ALCOHOL
2	SILICON DIOXIDE

Darunavir 600 mg and 800 mg Excipient Strategy and Commercial Opportunities

Last updated: August 27, 2026

Darunavir 600 mg and 800 mg tablets offer the strongest excipient opportunities in bioequivalent generics, taste-masked pediatric products, fixed-dose combinations, and differentiated low-cost formulations. The principal technical challenge is managing darunavir's poor aqueous solubility while preserving rapid, reproducible release. The reference product uses a conventional film-coated tablet platform with a short excipient list, leaving room for manufacturing, stability, swallowability, and supply-chain differentiation.[1]

What are the approved darunavir 600 mg and 800 mg dosage forms?

Darunavir is an HIV-1 protease inhibitor marketed by Janssen under the Prezista brand. The 600 mg tablet is used with ritonavir and other antiretroviral agents, generally in twice-daily regimens. The 800 mg tablet is used with ritonavir or cobicistat in once-daily regimens for appropriate patients.[1]

Attribute	Darunavir 600 mg	Darunavir 800 mg
Reference brand	Prezista	Prezista
Active ingredient	Darunavir, usually as darunavir ethanolate	Darunavir, usually as darunavir ethanolate
Administration	Oral tablet	Oral tablet
Typical adult regimen	600 mg twice daily with ritonavir	800 mg once daily with ritonavir or cobicistat
Tablet role	Higher-frequency treatment and treatment-experienced patients	Once-daily treatment in eligible patients
Key formulation issue	High drug load and twice-daily adherence	Very high drug load and tablet size
Pediatric relevance	Limited by swallowability and dose flexibility	Limited by fixed high dose
Main generic pathway	ANDA, subject to current FDA requirements	ANDA, subject to current FDA requirements

The 600 mg and 800 mg strengths are not interchangeable from a formulation perspective. The 800 mg tablet creates greater compression, dissolution, tablet-size, and mechanical-strength risks. The 600 mg product has more flexibility for a smaller tablet or a multi-tablet regimen but carries a higher adherence burden.

What excipients are used in Prezista tablets?

The US prescribing information identifies a conventional tablet composition. The inactive ingredients include microcrystalline cellulose, crospovidone, colloidal silicon dioxide, magnesium stearate, and talc. The film coating contains standard polymeric and mineral components, with colorants varying by strength.[1]

Reference excipient platform

Formulation function	Reference-product excipient category	Commercial relevance
Dilution and compactability	Microcrystalline cellulose	Supports direct compression or dry granulation
Disintegration	Crospovidone	Critical for high-dose release
Glidancy	Colloidal silicon dioxide	Improves powder flow and die filling
Lubrication	Magnesium stearate	Controls ejection but can slow wetting if overused
Anti-adherence and coating support	Talc	Supports processing and film coating
Film formation	Hypromellose-based coating system	Protects the tablet and controls appearance
Plasticization	Polyethylene glycol or comparable coating component	Reduces coating brittleness
Opacity and color	Titanium dioxide and iron oxide pigments	Enables strength identification

The short inactive-ingredient list creates a practical benchmark for generic development. A generic sponsor does not need to duplicate every excipient quantitatively, but the proposed product must meet pharmaceutical equivalence, bioequivalence, quality, and labeling requirements. Excipient changes that affect dissolution, permeability, particle wetting, or gastrointestinal performance can increase regulatory risk.

How should an excipient strategy address darunavir's solubility?

Darunavir is a high-dose, poorly water-soluble drug. The formulation objective is not simply to increase tablet hardness. It is to generate rapid and reproducible drug release from a tablet containing a large mass of active pharmaceutical ingredient.

The most commercially practical approach is a robust immediate-release formulation using one of four platforms:

1. Direct compression with a highly compactable filler.
2. Dry granulation to improve flow and content uniformity.
3. Wet granulation where API segregation or poor compressibility prevents direct compression.
4. A lipid or polymer-based solubilization system where dissolution remains inadequate.

Recommended development sequence

A cost-controlled development program should begin with the reference-like excipient platform:

• Microcrystalline cellulose or silicified microcrystalline cellulose for compactability.
• Crospovidone at a level sufficient to offset the high drug load.
• Colloidal silicon dioxide for flow.
• Magnesium stearate at the lowest level that provides acceptable ejection.
• A conventional hypromellose film coat.

The next development tier should assess:

• Copovidone or povidone as a wetting or binder component.
• Sodium starch glycolate as an alternative or co-disintegrant.
• Low-substituted hydroxypropyl cellulose for rapid tablet breakup.
• Mannitol or partially pregelatinized starch where mouthfeel or compactability is important.
• Surfactant-containing systems if dissolution is consistently below the target profile.
• Amorphous solid-dispersion technology only if a conventional formulation cannot meet dissolution and stability requirements.

A formulation should avoid unnecessary excipient complexity. Every additional excipient increases supplier qualification, extractables and leachables review, impurity assessment, stability testing, and regulatory justification.

What formulation patents could protect darunavir products?

The strongest formulation patent opportunities are unlikely to arise from claiming a conventional darunavir tablet with standard excipients. Broad composition claims covering darunavir and basic tablet excipients face prior-art and obviousness pressure, particularly after long commercial use of the reference product.

More defensible claim categories include:

Amorphous and solid-dispersion systems

Claims may cover:

• Darunavir in an amorphous state.
• Specific polymer ratios.
• Spray-dried particles.
• Stabilized supersaturation.
• Controlled particle-size distributions.
• Defined dissolution performance under discriminatory conditions.

These systems can support a differentiated product, but they create higher manufacturing and stability costs.

Taste-masked oral products

A taste-masked suspension, orally disintegrating tablet, granule, or multiparticulate product could address pediatric and swallowing barriers. Potential claim elements include:

• Polymer-coated darunavir particles.
• Ion-exchange resin complexes.
• Lipid-coated particles.
• pH-triggered release.
• Specific sweetener and flavor systems.
• Reduced bitterness without delaying intestinal release.

Taste masking is commercially relevant because darunavir is used in pediatric populations, while the tablet strengths are not optimized for children who cannot swallow large tablets.[1]

Abuse-resistant or adherence-oriented delivery

This is a lower-priority area for darunavir. The clinical market is not centered on abuse liability. Long-acting injectable or implantable delivery would require major clinical and regulatory investment and would compete with existing long-acting HIV products.

Fixed-dose combinations

A formulation containing darunavir with cobicistat, ritonavir, or other antiretroviral agents may be commercially attractive. Combination products face compatibility risks, dose-ratio constraints, separate release specifications, and potential patent claims covering the combination or dosing regimen.

What commercial opportunities exist for darunavir excipients?

1. Bioequivalent generic tablets

This is the largest near-term opportunity. A generic manufacturer can compete on:

• Lower manufacturing cost.
• Smaller tablet dimensions.
• Improved packaging.
• Reduced tablet friability.
• More efficient coating.
• Regional supply reliability.
• Alternative excipient sourcing.

The 800 mg strength is particularly suitable for process innovation because its high drug load magnifies differences in powder flow, compaction, lubrication, and dissolution.

2. Pediatric oral suspension

An oral suspension can address patients who cannot swallow tablets. The commercial requirements are more demanding than for a tablet because the product must control:

• Sedimentation and redispersibility.
• Dose uniformity after shaking.
• Chemical stability in an aqueous or semi-aqueous medium.
• Microbial preservation.
• Palatability.
• Device dosing accuracy.
• Compatibility with enteral administration.

A suspension platform using a structured vehicle, polymeric suspending agent, sweetener, preservative, and taste-masking system could be differentiated from standard tablets. The reference product has an oral suspension presentation, which means a new sponsor would need a clear advantage in taste, stability, storage, dosing flexibility, or cost.[1]

3. Orally disintegrating and multiparticulate products

An orally disintegrating tablet or coated granule could target patients with dysphagia. The main technical risk is that rapid oral disintegration may expose the drug's bitter taste. A multiparticulate product allows the drug to be coated separately from the final dosage form, improving taste control and dose flexibility.

4. Regional products for resource-limited markets

Darunavir is used in global HIV programs and public-sector procurement. Products with lower excipient cost, simplified coating, long shelf life, and broad storage tolerance can compete in markets where cold-chain infrastructure is limited. A room-temperature-stable, heat-tolerant product has greater procurement value than a technically sophisticated formulation with high production cost.

5. Excipient and process licensing

The most licensable technologies include:

• Co-processed direct-compression excipients.
• High-load tableting systems.
• Taste-masked darunavir microparticles.
• Spray-dried solubilization systems.
• Continuous blending and compression processes.
• Low-cost film-coating platforms.
• Moisture-barrier packaging systems.

Licensing value depends on whether the technology produces a measurable regulatory or commercial advantage. A formulation that only changes excipient identity without improving dissolution, cost, stability, or patient use will have limited negotiating value.

Which excipients create the greatest manufacturing advantage?

Silicified microcrystalline cellulose is a practical candidate for improving flow and compaction in high-dose tablets. It can reduce dependence on separate glidants and may support direct compression. The tradeoff is higher raw-material cost and the need to demonstrate equivalent performance against the reference product.

Crospovidone is well suited to high-drug-load immediate-release tablets because it promotes rapid capillary water uptake without forming a persistent gel. Excessive use can reduce tablet strength or increase friability, so the concentration should be optimized with compression force and particle size.

Magnesium stearate requires tight control. Over-lubrication can create hydrophobic particle surfaces, slowing wetting and dissolution. This is especially important for a poorly soluble drug. Blending time, lubricant grade, specific surface area, and shear history should be part of the control strategy.

Film-coating excipients can reduce commercial cost without changing the core formulation. A thin, fast-drying hypromellose coating with optimized pigment loading can improve throughput and reduce coating-pan time. Packaging must control moisture uptake and prevent color migration or tablet surface defects.

How do 600 mg and 800 mg formulations compare commercially?

Commercial factor	600 mg tablet	800 mg tablet
Patient use	Twice-daily treatment in specified regimens	Once-daily treatment in specified regimens
Formulation difficulty	High	Very high
Tablet-size pressure	Significant	More severe
Potential for mini-tablet or multi-unit design	Moderate	High
Generic substitution value	Strong in treatment-experienced markets	Strong in once-daily markets
Pediatric adaptation	Requires lower-dose flexibility	Usually requires a separate pediatric platform
Excipient differentiation	Process and dissolution	Tablet-size, mechanical strength, and dissolution
Manufacturing risk	Moderate	High

The 800 mg product is the better candidate for a high-load tableting technology. The 600 mg product is better suited to a platform that emphasizes flexibility, lower unit cost, and potential dose customization.

What is the FDA regulatory pathway for a generic darunavir tablet?

A standard generic tablet would normally proceed through an abbreviated new drug application. The applicant must demonstrate pharmaceutical equivalence and bioequivalence, meet current chemistry, manufacturing, and controls requirements, and address the applicable FDA product-specific guidance and labeling requirements.[2][3]

Key development work includes:

• Comparative dissolution using discriminatory methods.
• Comparative impurity and degradation profiles.
• Stability under long-term and accelerated conditions.
• Control of polymorphic or solid-state differences.
• Tablet identification and strength differentiation.
• Evaluation of food effect where required.
• Establishment of in-process controls for high-dose blending and compression.

A formulation with the same qualitative excipients as the reference product may simplify development, but quantitative differences still require performance justification.

What is the Orange Book and patent position for darunavir?

Darunavir's original US regulatory exclusivity and foundational patent protection were tied to the Prezista development program and the underlying protease-inhibitor patent estate. The five-year new chemical entity period and later patent rights have passed their principal commercial stage. Current generic risk depends on the live Orange Book listings, pediatric extensions, method-of-use claims, and any later patents covering combinations, formulations, or dosing regimens.[4]

Legal issue	Relevance to an excipient-led product
Composition-of-matter patents	Usually the largest historical barrier; cannot be avoided through excipient substitution while enforceable
Formulation patents	Can affect suspension, solid dispersion, taste masking, or modified-release products
Method-of-use patents	May affect labeled dosing or patient subpopulations
Orange Book listings	Determine listed patents relevant to an ANDA certification
Paragraph IV certification	Can create litigation exposure and a 180-day first-filer opportunity where applicable
Pediatric exclusivity	Can delay approval or commercial launch for covered listed products
Trade secrets	Process parameters may remain relevant even after patent expiry

An excipient strategy does not eliminate patent risk. It can reduce exposure to formulation claims when the generic uses a distinct composition and process, but it cannot neutralize claims that cover the active ingredient, a required combination, or a specific method of treatment.

Which companies are positioned to challenge darunavir exclusivity?

Generic antiretroviral competition typically comes from large multisource manufacturers, regional HIV suppliers, and vertically integrated API producers. The relevant competitive factors are:

• Access to darunavir API.
• Ability to manufacture high-dose tablets.
• ANDA approval status.
• Paragraph IV timing.
• Public-sector tender access.
• Supply reliability.
• Pricing in the United States and emerging markets.

The competitive field should be assessed through the FDA Orange Book, FDA Drugs@FDA records, ANDA approval announcements, court dockets, and procurement databases. Patent expiry alone does not establish immediate generic entry. Approval timing, tentative approval status, settlement terms, supply agreements, and regulatory deficiencies can materially change launch timing.

What manufacturing and IP barriers affect commercial entry?

The main manufacturing barriers are high drug loading, poor solubility, powder segregation, tablet-size constraints, and dissolution variability. The main IP barriers are not likely to be ordinary excipient selection. They are more likely to involve active-ingredient claims, combination products, pediatric formulations, or later-developed delivery systems.

A competitive development program should use:

1. A reference-like immediate-release tablet as the base case.
2. A high-load direct-compression or dry-granulation process.
3. A separate pediatric formulation track.
4. A taste-masking platform only if clinical demand supports the investment.
5. A patent review focused on live claims rather than expired foundational patents.
6. A dual-source strategy for microcrystalline cellulose, crospovidone, silica, and coating materials.

Key Takeaways

• Darunavir 600 mg and 800 mg are high-drug-load immediate-release tablet opportunities.
• The reference excipient platform is conventional and includes microcrystalline cellulose, crospovidone, colloidal silicon dioxide, magnesium stearate, talc, and film-coating materials.[1]
• The 800 mg strength has the greater need for compression, tablet-size, and dissolution innovation.
• Direct compression and dry granulation are the most commercially practical starting platforms.
• The strongest differentiated opportunities are pediatric suspensions, taste-masked multiparticulates, orally disintegrating products, and fixed-dose combinations.
• Excipient substitution alone is unlikely to create strong patent protection.
• Formulation patents are more defensible when tied to defined solid-state properties, taste masking, dissolution performance, or manufacturing parameters.
• Generic development requires current Orange Book review, ANDA strategy, comparative dissolution, stability data, and assessment of any live formulation or method-of-use claims.
• The best licensing opportunities are technologies that reduce cost, improve bioequivalence robustness, or solve pediatric administration problems.

FAQs

Can darunavir 800 mg be formulated as a smaller tablet?

Yes. A smaller tablet may be possible through higher-density granules, optimized particle-size distribution, co-processed excipients, or a multilayer or multiparticulate design. The product must retain acceptable hardness, friability, dissolution, content uniformity, and swallowability.

Is a lipid-based darunavir formulation commercially attractive?

It can be attractive if conventional immediate-release systems fail dissolution targets or if a pediatric or low-dose product requires improved exposure. For a standard generic tablet, lipid systems may add unnecessary manufacturing and stability complexity.

Which excipient is most important for darunavir dissolution?

No single excipient determines performance. Crospovidone, lubricant level, particle wetting, API particle size, compression force, and granule structure interact. Magnesium stearate control is particularly important because over-lubrication can delay wetting.

Could darunavir be developed as a long-acting injectable?

A long-acting injectable would require a new formulation, extensive pharmacokinetic and clinical development, and a competitive assessment against approved long-acting HIV therapies. It is a platform-development opportunity rather than a conventional generic-excipient opportunity.

Does a different excipient automatically avoid darunavir patent infringement?

No. A different excipient may avoid a narrow formulation claim, but it does not avoid active-ingredient, combination, dosing, method-of-use, or broader formulation claims. Patent clearance must be performed against the live claims relevant to the target jurisdiction.

References

1. Janssen Pharmaceuticals, Inc. (2023). Prezista (darunavir) tablets and oral suspension: US prescribing information. U.S. Food and Drug Administration.

2. U.S. Food and Drug Administration. (2013). Guidance for industry: ANDAs for certain highly purified synthetic peptides. FDA.

3. U.S. Food and Drug Administration. (2024). Bioequivalence studies with pharmacokinetic endpoints for drugs submitted under an ANDA. FDA.

4. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.