List of Excipients in Branded Drug DOXYLAMINE SUCCINATE AND PYRIDOXINE HYDROCHLORIDE

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Bryant Ranch Prepack	DOXYLAMINE SUCCINATE AND PYRIDOXINE HYDROCHLORIDE	doxylamine succinate and pyridoxine hydrochloride	63629-8358	ALCOHOL
Bryant Ranch Prepack	DOXYLAMINE SUCCINATE AND PYRIDOXINE HYDROCHLORIDE	doxylamine succinate and pyridoxine hydrochloride	63629-8358	AMMONIA
Bryant Ranch Prepack	DOXYLAMINE SUCCINATE AND PYRIDOXINE HYDROCHLORIDE	doxylamine succinate and pyridoxine hydrochloride	63629-8358	BUTYL ALCOHOL

Generic Drugs Containing DOXYLAMINE SUCCINATE AND PYRIDOXINE HYDROCHLORIDE

Company	Ingredient	NDC	Excipient
Mylan Pharmaceuticals Inc	doxylamine succinate and pyridoxine hydrochloride	0378-4615	AMMONIA
Mylan Pharmaceuticals Inc	doxylamine succinate and pyridoxine hydrochloride	0378-4615	CELLULOSE, MICROCRYSTALLINE
Mylan Pharmaceuticals Inc	doxylamine succinate and pyridoxine hydrochloride	0378-4615	FERROSOFERRIC OXIDE

What are the Most Frequently-Used Excipients in DOXYLAMINE SUCCINATE AND PYRIDOXINE HYDROCHLORIDE?

# Of NDCs	Excipient
5	AMMONIA
3	BUTYL ALCOHOL
5	CELLULOSE, MICROCRYSTALLINE

Doxylamine Succinate and Pyridoxine Hydrochloride: Excipient Strategy, Patent Position and Commercial Opportunities

Last updated: August 2, 2026

Doxylamine succinate and pyridoxine hydrochloride is a prescription combination for nausea and vomiting of pregnancy. The commercial opportunity is concentrated in modified-release oral products, differentiated dosing, improved swallowability, and lower-cost generic manufacturing. The main technical barrier is coordinated control of two active ingredients with different dose levels, stability profiles, and release requirements.

In the United States, the principal reference products are Diclegis, a 10 mg/10 mg delayed-release tablet, and Bonjesta, a 20 mg/20 mg extended-release tablet. Both are marketed by Duchesnay. The active ingredients are an antihistamine, doxylamine succinate, and vitamin B6, pyridoxine hydrochloride. FDA-approved products are prescription drugs, and generic entry proceeds through the ANDA pathway rather than the biosimilar pathway.[1][2]

What products contain doxylamine succinate and pyridoxine hydrochloride?

The principal products use modified-release tablets rather than immediate-release dosage forms. The formulation strategy separates dosing from administration timing and is designed to provide overnight or sustained exposure.

Product	Active strength	Dosage form	Release profile	U.S. sponsor or marketer	Primary commercial role
Diclegis	10 mg doxylamine succinate / 10 mg pyridoxine HCl per tablet	Delayed-release tablet	Delayed release	Duchesnay	Established reference product
Bonjesta	20 mg doxylamine succinate / 20 mg pyridoxine HCl per tablet	Extended-release tablet	Extended release	Duchesnay	Higher-strength, lower-tablet-burden product
Generic equivalents	Generally 10 mg/10 mg	Delayed-release tablet	Reference-equivalent release required	Multiple ANDA applicants or holders	Price competition and pharmacy substitution

The products are indicated when conservative management of nausea and vomiting of pregnancy is inadequate. The labeling instructs patients to take the tablets on a scheduled basis, not as an immediate rescue treatment.[1][2]

How does the active-ingredient combination affect formulation design?

Doxylamine succinate and pyridoxine hydrochloride differ in physicochemical properties, dose requirements, and clinical function.

Formulation issue	Doxylamine succinate	Pyridoxine hydrochloride	Excipient implication
Pharmacologic role	Sedating antihistamine	Vitamin B6 component	Release must preserve the intended exposure profile of both actives
Dose	Relatively higher mass per tablet	Lower mass per tablet	Content-uniformity controls are critical
Patient concern	Drowsiness and additive sedation	Generally well tolerated at labeled doses	Avoid unnecessary absorption acceleration
Stability	Sensitive to moisture and processing conditions	Requires control of moisture, light, and degradation products	Moisture-barrier packaging has commercial value
Manufacturing	Requires uniform distribution in a low-dose combination	Low-dose blending can create segregation risk	Granulation or ordered mixing may be needed

A successful formulation must prevent pyridoxine segregation while maintaining consistent doxylamine content. This is more difficult than producing a conventional high-dose single-ingredient tablet.

What excipients are used in Diclegis and Bonjesta?

FDA labeling identifies conventional pharmaceutical excipients, including microcrystalline cellulose, croscarmellose sodium, colloidal silicon dioxide, magnesium stearate, and coating materials. The exact excipient profile differs by product and dosage form, and the approved label should control any regulatory or competitive analysis.[1][2]

The excipients have distinct technical functions:

Excipient category	Typical function	Commercial relevance
Microcrystalline cellulose	Diluent and compressibility aid	Supports robust tablet manufacture
Croscarmellose sodium	Disintegrant	Controls tablet breakup after the delayed-release barrier is removed
Colloidal silicon dioxide	Glidant and moisture-control aid	Improves powder flow and blend uniformity
Magnesium stearate	Lubricant	Controls ejection force, but excess use can slow dissolution
Film-coating polymers	Protection, appearance, swallowing, and release control	Potential source of formulation differentiation
Talc or mineral coating aids	Anti-tack and coating-process support	Must be controlled for functionality and quality
Barrier or enteric polymers	Delayed-release performance	Central to bioequivalence and formulation IP
Packaging desiccants and high-barrier materials	Moisture protection	May extend shelf life without changing the tablet

The commercial opportunity is not in replacing an excipient merely to create a different ingredient list. The value is in demonstrating a measurable improvement in release reproducibility, stability, manufacturability, patient handling, or regulatory robustness.

What excipient strategies create commercial opportunities?

Moisture-control strategy

A moisture-sensitive formulation can benefit from a low-water-activity manufacturing process, controlled-humidity blending, and high-barrier packaging. Polyvinyl chloride and aluminum blister systems should be evaluated against cold-form foil or other high-barrier configurations.

Commercial benefits include:

• longer shelf life;
• lower risk of pyridoxine degradation;
• improved release consistency;
• reduced dependence on specialized storage;
• fewer coating defects caused by moisture migration.

Packaging is not normally a substitute for formulation work. A strong development program uses packaging, coating, and manufacturing controls together.

Low-segregation blend design

Pyridoxine hydrochloride is present at a lower dose than the overall tablet mass. Direct compression can create potency variation if particle-size distributions, density, or electrostatic behavior differ between the actives and excipients.

Potential strategies include:

• particle-size engineering;
• co-processing with a diluent;
• dry granulation;
• wet granulation where chemical and physical stability support it;
• ordered mixing;
• low-shear blending followed by validated lubrication;
• in-process blend uniformity monitoring.

A proprietary co-processed excipient system could support a formulation patent if it produces a defined technical result, such as improved content uniformity or reduced dissolution variability.

Delayed-release coating strategy

Diclegis relies on delayed release. The coating must withstand gastric conditions and release the active ingredients reproducibly after the intended lag period. Formulation variables include polymer type, coating weight gain, pore-former concentration, plasticizer selection, and curing conditions.

Potential commercial improvements include:

• narrower lag-time distribution;
• reduced sensitivity to gastric pH;
• lower coating weight;
• faster and more consistent release after the lag period;
• reduced tablet size;
• improved stability during storage.

A generic developer must match the reference product's clinically relevant release behavior. A different coating can be commercially useful only if it remains bioequivalent and meets the applicable FDA product-specific requirements.

Extended-release strategy for higher-strength products

Bonjesta provides a higher-strength 20 mg/20 mg presentation. The principal value proposition is reduced tablet burden for patients who require higher scheduled dosing. Extended-release designs may use matrix systems, multilayer structures, or specialized coating architectures.

Commercial opportunities include:

• once-daily or simplified administration;
• smaller total daily tablet count;
• lower pill burden during pregnancy;
• improved adherence;
• differentiated packaging and titration instructions.

The development risk is higher than for a conventional delayed-release tablet because the sponsor must control both release duration and dose proportionality.

Patient-centered excipient selection

Pregnancy products require a conservative excipient policy. Development teams should prioritize:

• established oral excipients with extensive human exposure;
• low odor and neutral taste;
• minimal gastrointestinal irritation;
• low moisture uptake;
• compatibility with film coating;
• avoidance of unnecessary colorants and flavor systems;
• tablet dimensions that support swallowing during nausea.

Chewable, orally disintegrating, liquid, and sprinkle products could expand administration options, but they introduce risks. Rapid disintegration may alter doxylamine exposure, increase unpleasant taste, or undermine the delayed-release objective. Liquid formulations also create stability, preservative, and dosing-accuracy challenges.

What formulations are protected by patents or regulatory exclusivity?

The relevant intellectual-property categories are composition, modified-release formulation, manufacturing process, dosing regimen, and method of use.

IP category	Potential claim scope	Competitive significance
Active composition	Doxylamine succinate plus pyridoxine hydrochloride	Usually vulnerable where the combination and therapeutic use are well established
Delayed-release tablet	Polymer coating, layered structure, lag-time control	More relevant to Diclegis-style generic competition
Extended-release tablet	Sustained-release matrix or coating	More relevant to Bonjesta-style differentiation
Manufacturing process	Granulation, coating, curing, and blend controls	Can create a practical barrier even where composition claims are narrow
Method of use	Scheduled dosing for nausea and vomiting of pregnancy	May affect ANDA labeling and Paragraph IV strategy
Packaging and stability	Moisture-barrier configuration or shelf-life performance	Often supports secondary protection rather than broad market exclusion

FDA's Orange Book identifies patents and regulatory exclusivity associated with approved drug products. The Orange Book should be read together with the approved labeling, patent scope, and court docket because listing does not establish ultimate validity or infringement.[3]

The core combination has limited strategic value if claimed broadly without a novel delivery feature. The stronger patent position generally comes from a technically defined release system, a manufacturing process with unexpected performance, or a clinically relevant dosing regimen supported by data.

When does doxylamine-pyridoxine lose exclusivity?

Regulatory exclusivity and patent protection are separate.

Diclegis received FDA approval in 2013. Bonjesta received FDA approval in 2016. The products do not have biologic exclusivity because they are small-molecule drugs. Any five-year new chemical entity exclusivity associated with the underlying approval does not create a current barrier to generic entry. The remaining protection depends primarily on listed patents, pediatric exclusivity if applicable, and the status of ANDA litigation.[1][2][3]

A commercial launch analysis should distinguish:

1. the earliest lawful ANDA approval date;
2. the earliest date a generic can launch after patent litigation or settlement;
3. the expiration date of each relevant listed patent;
4. any 180-day first-filer exclusivity;
5. the scope of the generic label;
6. whether the generic duplicates the delayed-release or extended-release presentation.

A single patent expiration date is not sufficient to forecast entry. One unexpired method-of-use patent can delay a full-label generic if the applicant cannot carve out the patented use. Conversely, a noninfringement or invalidity position may permit approval before expiration if litigation and regulatory requirements are resolved.

How do Paragraph IV challenges affect generic entry?

An ANDA applicant may submit a Paragraph IV certification asserting that a listed patent is invalid, unenforceable, or not infringed. The sponsor can sue within the statutory period, triggering a potential 30-month stay of approval under the Hatch-Waxman framework, subject to statutory exceptions and court developments.[4]

For doxylamine-pyridoxine products, the main Paragraph IV issues are likely to involve:

• whether the claimed release profile is sufficiently distinct and nonobvious;
• whether the generic's coating or process falls within the patent claims;
• whether the patent claims a method that the generic label will include;
• whether a label carve-out can remove the patented use;
• whether the patent is properly listed for the approved product.

Generic applicants may use one or more of four entry routes:

Entry route	Description	Market effect
Paragraph III	Applicant accepts patent validity through expiry	Entry follows patent expiration
Paragraph IV	Applicant challenges patent validity or infringement	Earlier entry possible, with litigation risk
Section viii carve-out	Applicant omits a patented method of use	Partial-label entry
Authorized generic or settlement	Entry occurs under negotiated terms	Timing depends on agreement

What is the FDA regulatory status of the products?

Diclegis and Bonjesta are FDA-approved prescription products for nausea and vomiting of pregnancy in women who do not respond to conservative management.[1][2]

The principal regulatory requirements are:

• ANDA applicants must demonstrate pharmaceutical equivalence and bioequivalence;
• delayed-release products require dissolution testing that reflects the release mechanism;
• extended-release products require characterization of the release profile and pharmacokinetics;
• inactive ingredients must be suitable for the route, dosage form, and target population;
• labeling must address somnolence and additive central-nervous-system depression;
• manufacturing controls must maintain potency and release performance through shelf life.

The product is not a biologic, so biosimilar competition is not relevant. The competitive pathway is conventional generic substitution, subject to state pharmacy law and product-specific substitution rules.

How strong is the patent estate for doxylamine-pyridoxine products?

The estate is strongest around delivery technology and dosing architecture, not the basic presence of doxylamine and pyridoxine.

Patent factor	Relative strength	Reason
Broad active-ingredient combination	Low to moderate	Combination and therapeutic use are well known
Delayed-release formulation	Moderate	Depends on claim specificity and prior art
Extended-release formulation	Moderate to strong	Higher value if release performance is clinically linked
Manufacturing process	Moderate	Stronger when process conditions produce measurable product attributes
Method of use	Moderate	Scope depends on dosing language and label coverage
Excipient-only substitution	Low	A new excipient list alone may not establish nonobviousness
Stability and packaging	Low to moderate	More useful for follow-on products and lifecycle management

A formulation patent is more defensible when it claims a defined combination of excipient ratios, coating weight, dissolution limits, particle properties, and manufacturing conditions tied to an unexpected result. Generic excipient substitution without a demonstrated technical advantage is less likely to create durable exclusivity.

Which companies are challenging or competing with the reference products?

Competition comes from three groups:

1. ANDA applicants seeking approval of delayed-release equivalents.
2. Companies developing alternative pregnancy-nausea products, including single-ingredient doxylamine or pyridoxine products.
3. Manufacturers offering private-label, contract-manufactured, or pharmacy-distributed products where legally permitted.

The most important competitive variable is not the number of applicants alone. It is the timing of final approval, the ability to match release performance, and the commercial position of the first approved generic.

Public FDA resources identify approved products, applicants, and Orange Book information. Court dockets and settlement documents determine whether a Paragraph IV challenge changes the effective entry date.[3][5]

What licensing deals and manufacturing opportunities exist?

The most practical licensing opportunities are formulation and manufacturing assets rather than a new active pharmaceutical ingredient.

Potential deal structures include:

• licensing a delayed-release coating platform;
• supplying a co-processed excipient blend;
• transferring a validated low-segregation manufacturing process;
• licensing high-barrier packaging with stability data;
• partnering on a lower-tablet-burden extended-release product;
• contract manufacturing for an ANDA holder;
• regional licensing for markets where pregnancy-nausea products have limited competition.

An excipient supplier can create greater value by providing a package of excipient composition, process parameters, analytical methods, and stability data. A commodity excipient alone is unlikely to command substantial exclusivity.

How does doxylamine-pyridoxine compare with competing pregnancy-nausea products?

Product strategy	Advantages	Limitations
Doxylamine/pyridoxine delayed release	Established indication, scheduled dosing, differentiated release	Sedation, formulation complexity, patent and bioequivalence requirements
Immediate-release pyridoxine	Simple manufacturing, low cost	May require combination therapy or more frequent dosing
Immediate-release doxylamine	Fast availability of antihistamine activity	Sedation and less controlled exposure
Extended-release combination	Lower tablet burden	Higher development and regulatory complexity
Chewable or orally disintegrating form	Easier administration for some patients	Taste, stability, and release-control challenges
Liquid formulation	Flexible dosing	Preservative, packaging, and dosing-accuracy risks

The reference-product advantage is the combination of an established clinical regimen and modified-release delivery. A follow-on product must improve patient handling or economics without creating a more difficult bioequivalence pathway.

What generic launch risks exist?

The main risks are:

• failure to reproduce the reference dissolution profile;
• dose segregation during scale-up;
• coating variability;
• pyridoxine degradation under moisture stress;
• tablet size or swallowability problems;
• inability to use the reference formulation's excipients;
• Paragraph IV litigation;
• method-of-use label restrictions;
• delayed approval caused by manufacturing deficiencies;
• limited commercial returns after multiple generic entrants.

The best generic development strategy is to select excipients that are pharmaceutically conventional but process-stable, then reserve patent investment for measurable release, stability, or manufacturing improvements.

What revenue exposure does the patent position create?

Public FDA approval materials do not provide product-level revenue for Diclegis or Bonjesta. Revenue exposure therefore depends on prescription volume, payer coverage, generic substitution, and the timing of competing approvals rather than on a publicly stated product-sales figure.[1][2]

The economic sensitivity is highest in the period between the first generic approval and broader multi-source competition. A first generic may obtain meaningful price and volume benefits, while later entrants face rapid erosion. The branded products can preserve value through:

• Bonjesta's higher-strength positioning;
• physician familiarity;
• adherence messaging;
• packaging and patient-support programs;
• lifecycle extensions such as alternate dosage forms;
• regional licensing and supply agreements.

Key Takeaways

• The commercial value of doxylamine succinate and pyridoxine hydrochloride lies in modified-release delivery, not the basic active combination.
• Excipient strategy should focus on moisture control, low-segregation blending, coating reproducibility, and patient acceptability.
• Diclegis and Bonjesta are FDA-approved small-molecule products; biosimilar competition does not apply.
• The strongest patent opportunities are technically defined delayed-release or extended-release systems, manufacturing processes, and supported dosing regimens.
• Generic entry depends on Orange Book patents, Paragraph IV certifications, litigation, settlements, label carve-outs, and bioequivalence.
• A differentiated excipient platform is more valuable when combined with process know-how, analytical methods, and stability data.
• Commercial exposure is concentrated around the first approved generic and the speed at which additional generic suppliers enter.

FAQs About Doxylamine Succinate and Pyridoxine Hydrochloride Excipient Strategy

Can a new excipient alone support a patent for doxylamine-pyridoxine tablets?

Usually, no. Patent value is stronger when the excipient produces an unexpected result, such as improved lag-time control, lower degradation, better content uniformity, or reduced tablet size.

Is an enteric coating required for doxylamine-pyridoxine delayed-release tablets?

A delayed-release product requires a release-control mechanism that withstands the intended gastric phase and releases the actives according to the target profile. An enteric polymer is one possible approach, but the approved reference mechanism and bioequivalence requirements control development.

Could an orally disintegrating doxylamine-pyridoxine product compete with Diclegis?

It could provide a patient-handling advantage, but rapid disintegration may conflict with the delayed-release design. The product would need a release system that preserves the reference exposure profile.

What packaging provides the best commercial advantage for this combination?

High-moisture-barrier blister packaging can reduce degradation risk and support shelf life. Its value is highest when stability data show a meaningful advantage over standard bottle packaging.

Does Bonjesta eliminate the need for delayed-release generic development?

No. Bonjesta and Diclegis have different strengths and release profiles. A generic applicant must match the specific reference product for which it seeks approval.

References

1. U.S. Food and Drug Administration. (2023). Diclegis: Prescribing information.
2. U.S. Food and Drug Administration. (2023). Bonjesta: Prescribing information.
3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
4. U.S. Congress. (1984). Drug Price Competition and Patent Term Restoration Act of 1984, Pub. L. No. 98-417.
5. U.S. Food and Drug Administration. (2024). Approved drug product and patent information resources.