# United States Patent 5,030,632: Temazepam Low-Dose Capsule Claims, Patent Scope, Expiration, and Competitive Landscape

U.S. Patent No. 5,030,632 covers a narrow method of treating transient insomnia using a hard gelatin capsule containing low-dose crystalline temazepam with specified particle-size and surface-area characteristics. The patent issued July 9, 1991, and its statutory term expired in 2008. The claims are no longer enforceable, but they remain relevant to historical Restoril development, generic formulation strategy, patent-term analysis, and prior-art review.

What does U.S. Patent 5,030,632 protect?

The patent protects a specific combination of therapeutic use, dose, dosage form, and physical properties of temazepam. It does not broadly claim temazepam, all temazepam formulations, or every treatment of insomnia with temazepam.

Claim structure

Claim	Protected subject matter	Additional limitation
1	Treating transient insomnia in a human by administering a hard gelatin capsule containing crystalline temazepam	5 to 10 mg; surface area of 0.65 to 1.1 m²/g; at least 95% of particles below 65 microns
2	Method of claim 1	Dose narrowed to 6 to 8 mg
3	Method of claim 1	Dose narrowed to 7.5 mg

Claim 1 is the independent claim. Claims 2 and 3 add dose restrictions and therefore cannot be infringed unless every limitation of claim 1 is also satisfied.

The claim language supplied for claim 1 states "not more than 5 to 10 milligrams." That wording is internally awkward. In practical claim analysis, it is best read in light of the patent specification and prosecution history as defining a 5-to-10-mg range, subject to any contrary construction adopted by a court.

What are the required elements of the patent claims?

A potentially infringing product or administration method would need to satisfy all material limitations below.

1. Treatment of transient insomnia

The method requires treatment of transient insomnia, rather than insomnia generally. A product labeled only for chronic insomnia, sleep disturbance, or another indication could present a claim-construction issue.

The relevant question would be whether the administered product is used for the claimed condition. For a labeled generic product, the prescribing information, indication, dosage instructions, promotional materials, and actual use could be relevant to induced-infringement analysis.

2. Administration to a human

The claims are method claims. They require administration to a human patient. Animal studies, in vitro testing, stability work, and manufacturing activity alone do not practice the claimed treatment method.

The direct actor is ordinarily the person administering the capsule or the patient taking it. A manufacturer could face indirect-infringement theories only if the other statutory elements were satisfied.

3. Hard gelatin capsule

The dosage form is limited to a hard gelatin capsule. The claim does not expressly cover:

Soft gelatin capsules;
Tablets;
Orally disintegrating tablets;
Liquid solutions;
Suspensions;
Sublingual products;
Transdermal systems; or
Other delivery systems.

A hard gelatin capsule containing the same dose and active ingredient would fall within the dosage-form limitation if the remaining physical-property limitations were met.

4. Crystalline temazepam

The active ingredient must be crystalline temazepam. The claim does not expressly identify a particular polymorph, crystal habit, solvated form, or crystalline purity level.

That distinction matters. A formulation containing amorphous temazepam might avoid the literal crystalline limitation, although the factual and legal analysis would depend on the actual solid-state composition and any applicable equivalents analysis.

5. Surface area of 0.65 to 1.1 m²/g

The temazepam must have a specified surface-area range. Surface area is a measurable physical property that can vary with:

Particle-size distribution;
Milling or micronization;
Crystal morphology;
Agglomeration;
Sample preparation;
Moisture content; and
The analytical method used.

A product-development team would need to characterize the active pharmaceutical ingredient, not merely the finished capsule. The patent claim is directed to the crystalline temazepam in the capsule.

6. Particle-size limitation

At least 95% of the temazepam must have particle diameters below 65 microns. This is a distribution requirement, not a requirement that every particle be below 65 microns.

A batch could satisfy the claim while containing a limited fraction of particles at or above 65 microns. Conversely, a nominally micronized material could fall outside the claim if 5% or more of the particles meet or exceed the threshold, depending on the measurement protocol.

Particle-size evidence would likely require:

Batch-specific testing;
A defined analytical technique;
Raw distribution data;
Sampling records;
Method validation; and
Testing of retained commercial samples.

How do claims 2 and 3 narrow the patent scope?

Claim 2 covers administration of 6 to 8 mg. Claim 3 covers administration of exactly 7.5 mg, subject to the full set of claim 1 limitations.

The relationship is:

A 7.5-mg product falls within the dose range of claim 2.
A 7.5-mg product also falls within claim 3.
A 5-mg product may fall within claim 1 but not claim 2 or claim 3.
A 10-mg product may fall within claim 1 but not claim 2 or claim 3.
A 6-mg or 8-mg product may fall within claim 2 if all claim 1 limitations are met.
A 7.5-mg product using a tablet rather than a hard gelatin capsule would not literally meet the capsule limitation.

The dependent claims are commercially important because they focus on the lower-dose regimen associated with reduced exposure relative to traditional temazepam dosing. They do not remove the need to prove the particle-size, surface-area, crystalline-form, capsule, and transient-insomnia limitations.

What is the patent’s legal status and expiration date?

U.S. Patent 5,030,632 issued July 9, 1991. Its ordinary U.S. patent term was 17 years from issuance because it belonged to the pre-Uruguay Round patent-term regime. On that basis, the patent expired July 9, 2008, absent an unusual term adjustment, terminal disclaimer, or other record-specific modification. The patent is therefore expired and cannot presently block generic manufacture, sale, or use.

Event	Date
U.S. patent issued	July 9, 1991
Standard term basis	17 years from issue
Expected expiration	July 9, 2008
Current enforceability	Expired

The patent should not be treated as a live exclusivity barrier. Its claims may still be relevant as prior art, as evidence of historical formulation technology, or in an invalidity analysis involving later patents.

What is the FDA and Orange Book status of temazepam?

Temazepam is an FDA-approved benzodiazepine hypnotic indicated for short-term treatment of insomnia. Restoril is the reference-brand product historically associated with temazepam. Generic temazepam capsules have been approved through the abbreviated new drug application pathway.

Regulatory position

Issue	Assessment
Active ingredient	Temazepam
Therapeutic class	Benzodiazepine sedative-hypnotic
Dosage forms	Primarily oral capsules
FDA pathway for generics	ANDA
Reference product	Restoril
Controlled-substance status	Schedule IV under the federal Controlled Substances Act
Biologic status	Not a biologic
Biosimilar pathway	Not applicable
Patent 5,030,632	Expired

The Orange Book is relevant for listed patents associated with approved drug products, but an expired patent does not create current FDA exclusivity. Orange Book listing and patent enforceability are separate questions. A patent may appear historically in FDA records while having no remaining exclusionary term.

FDA approval of a generic temazepam capsule does not necessarily establish that the generic reproduces every physical parameter described in Patent 5,030,632. Bioequivalence approval and patent infringement are separate analyses.

When did generic temazepam lose exclusivity?

The patent-based exclusivity associated with Patent 5,030,632 ended in 2008. Any earlier FDA marketing exclusivity would have been separate from the patent and would not extend the patent term.

Because temazepam is a small-molecule drug, the relevant competitive pathway is an ANDA, not a biosimilar application. Generic applicants could certify against listed patents under Paragraphs I through IV or wait for patent expiration under Paragraph III, depending on the patent records applicable at filing.

Paragraph IV challenge exposure

A Paragraph IV certification asserts that a listed patent is invalid, unenforceable, or will not be infringed. For Patent 5,030,632:

A new Paragraph IV challenge is commercially unnecessary because the patent has expired.
Historical Paragraph IV activity would have been relevant only before July 9, 2008.
A generic applicant seeking approval before expiration could have challenged the patent or designed around one or more limitations.
A post-expiration launch does not require defeating the expired claims.

No current litigation risk should be assigned to the expired patent solely because it once covered a temazepam capsule regimen.

What formulation and method-of-use patents cover temazepam?

Patent 5,030,632 is a formulation-linked method-of-use patent. Its novelty is concentrated in the combination of a low dose with specific solid-state properties and a hard gelatin capsule.

It does not claim:

A new chemical entity;
A new temazepam molecule;
A broad temazepam composition;
All doses of temazepam;
All insomnia treatments;
A specific manufacturing process; or
A specific polymorph by name.

Potential adjacent patent categories

A broader temazepam patent search would examine:

Composition patents covering temazepam itself.
Polymorph or crystalline-form patents.
Particle-size and micronization patents.
Capsule-fill and dissolution patents.
Modified-release or abuse-deterrent formulations.
Combination products.
Methods for reducing next-day sedation.
Pediatric, geriatric, or other patient-specific dosing.
Manufacturing and purification processes.
Packaging or stability systems.

Later patents would need to be evaluated separately. Patent 5,030,632 does not establish that a later formulation patent is valid or enforceable, and its expiration does not automatically invalidate later patents with different claims.

How strong was the patent estate for Patent 5,030,632?

The estate was narrow in claim count but potentially meaningful during its term because the limitations mapped onto a commercial capsule product and a defined low-dose regimen.

Strengths

Claim 1 combined treatment, dose, dosage form, crystallinity, surface area, and particle size.
Claim 3 targeted a precise 7.5-mg dose.
Particle size and surface area could be documented through batch records and analytical testing.
The claims could potentially cover a commercially supplied product rather than only a research formulation.

Vulnerabilities

The claims were narrow and required proof of multiple limitations.
The physical-property limitations could permit design-around development.
A non-capsule dosage form could avoid the express dosage-form requirement.
A dose outside the specified range could avoid literal infringement.
The "transient insomnia" limitation could create an indication and labeling dispute.
The wording "not more than 5 to 10 milligrams" could invite claim-construction scrutiny.
Crystalline-form and particle-size evidence can vary with testing methodology.
Method claims generally create more complex enforcement issues than composition claims.

The patent was therefore stronger against an exact commercial copy than against a deliberately engineered alternative.

Which companies challenged or competed with the patented product?

The principal competitive route was generic temazepam approval rather than biosimilar competition. Companies seeking to market generic capsules could pursue:

A Paragraph III certification after patent expiry;
A Paragraph IV certification before expiry;
A formulation design-around;
A different dose or dosage form; or
A product that met bioequivalence requirements without reproducing the claimed physical parameters.

Public FDA records should be used to identify the specific ANDA sponsors and approval dates. The patent itself does not establish which companies filed challenges, entered settlements, or launched products.

No current biosimilar risk exists because temazepam is a chemically synthesized small molecule. The relevant risks are generic price competition, controlled-substance distribution requirements, manufacturing compliance, and product-quality consistency.

What litigation and settlement issues affected the patent?

An expired patent does not create current injunctive or launch risk. Any historical litigation would need to be assessed from federal court dockets, Patent Trial and Appeal Board records, and FDA Paragraph IV notices.

The principal historical disputes would likely have involved:

Whether a generic capsule contained crystalline temazepam;
Whether the active ingredient met the 0.65-to-1.1 m²/g surface-area range;
Whether at least 95% of particles were below 65 microns;
Whether the product was indicated for transient insomnia;
Whether the claims were enabled and adequately described;
Whether the claims were anticipated or obvious; and
Whether a generic applicant’s proposed labeling induced infringement.

No settlement agreement should be inferred from the existence of the patent. Settlement terms, launch dates, and any authorized-generic arrangements require separate documentary confirmation.

What manufacturing and IP barriers remain for generic temazepam?

Patent 5,030,632 no longer creates a manufacturing barrier. Operational barriers remain because temazepam is a controlled substance and because capsule quality depends on active-ingredient control.

Key technical controls include:

Crystalline-form consistency;
Particle-size distribution;
Surface-area measurement;
Blend uniformity;
Dissolution performance;
Content uniformity;
Encapsulation weight control;
Moisture and stability control; and
Controlled-substance inventory and security procedures.

A manufacturer can face FDA inspection, cGMP, diversion-control, supply-chain, and recall exposure even when no patent remains enforceable.

How does Patent 5,030,632 compare with a conventional temazepam patent?

Issue	Patent 5,030,632	Broad composition patent
Claim type	Method of treatment	Composition or compound
Active ingredient	Crystalline temazepam	May cover temazepam broadly
Dose	5 to 10 mg; dependent claims narrow to 6 to 8 mg and 7.5 mg	Often broader or unspecified
Dosage form	Hard gelatin capsule	May cover multiple forms
Physical properties	Surface area and particle-size limits	Often absent or less specific
Indication	Transient insomnia	May be absent
Design-around potential	Relatively high	Usually lower if composition claim is valid
Current status	Expired	Must be assessed patent by patent

Key Takeaways

U.S. Patent 5,030,632 covers a narrow low-dose temazepam treatment method.
The core combination is a hard gelatin capsule, crystalline temazepam, 5-to-10 mg dose, 0.65-to-1.1 m²/g surface area, and a particle distribution in which 95% is below 65 microns.
Claim 2 narrows the dose to 6 to 8 mg. Claim 3 focuses on 7.5 mg.
The patent issued July 9, 1991, and its ordinary patent term expired July 9, 2008.
The patent is not a current barrier to generic temazepam entry.
Temazepam is a small-molecule controlled substance, so biosimilar analysis does not apply.
Current commercial risk centers on generic competition, FDA compliance, controlled-substance controls, and any later unexpired patents.
Historical infringement analysis would turn heavily on particle-size testing, surface-area methodology, crystalline form, capsule composition, labeling, and the transient-insomnia limitation.

FAQs About U.S. Patent 5,030,632

Does Patent 5,030,632 cover all temazepam capsules?

No. It covers a specific method using a hard gelatin capsule with defined dose, crystalline form, surface area, and particle-size properties.

Does a 15-mg temazepam capsule infringe the patent?

Not literally under the supplied claims because the claimed dose is 5 to 10 mg. It also would not fall within the 6-to-8-mg or 7.5-mg dependent claims.

Can a temazepam tablet avoid Patent 5,030,632?

Yes, a tablet would not literally satisfy the hard gelatin capsule limitation. Other patents or regulatory requirements could still apply.

Is a generic temazepam product required to match the claimed particle size?

No. FDA bioequivalence requirements and patent claim limitations are separate. A generic must meet applicable FDA standards, but it is not required to practice an expired patent claim.

Is temazepam subject to biosimilar competition?

No. Temazepam is a chemically synthesized small molecule. Generic competition proceeds through the ANDA framework rather than the biosimilar pathway.

References

U.S. Patent and Trademark Office. (1991). U.S. Patent No. 5,030,632, Temazepam in a hard gelatin capsule. U.S. Department of Commerce.
U.S. Food and Drug Administration. (n.d.). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/
U.S. Food and Drug Administration. (n.d.). Drugs@FDA: FDA-approved drugs. https://www.accessdata.fda.gov/scripts/cder/daf/
U.S. Food and Drug Administration. (2017). Approved drug products with therapeutic equivalence evaluations. U.S. Department of Health and Human Services.
Controlled Substances Act, 21 U.S.C. §§ 801-971.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Belgium	1000318	⤷ Start Trial
Canada	1302886	⤷ Start Trial
Switzerland	673947	⤷ Start Trial
Germany	3731840	⤷ Start Trial
France	2604091	⤷ Start Trial
United Kingdom	2195242	⤷ Start Trial
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Details for Patent: 5,030,632

Summary for Patent: 5,030,632