LIMBITROL Drug Patent Profile

Which patents cover Limbitrol, and when can generic versions of Limbitrol launch?

Limbitrol is a drug marketed by Chartwell Rx and is included in one NDA.

The generic ingredient in LIMBITROL is amitriptyline hydrochloride; chlordiazepoxide. One supplier is listed for this compound. Additional details are available on the amitriptyline hydrochloride; chlordiazepoxide profile page.

Summary for LIMBITROL

US Patents:	0
Applicants:	1
NDAs:	1

US Patents and Regulatory Information for LIMBITROL

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Chartwell Rx	LIMBITROL	amitriptyline hydrochloride; chlordiazepoxide	TABLET;ORAL	016949-001	Approved Prior to Jan 1, 1982		DISCN	Yes	No
Chartwell Rx	LIMBITROL DS	amitriptyline hydrochloride; chlordiazepoxide	TABLET;ORAL	016949-002	Approved Prior to Jan 1, 1982		DISCN	Yes	No

Last updated: July 10, 2026

LIMBITROL (amitriptyline/chlordiazepoxide) Investment Scenario and Patent-Fundamentals Deep Dive

Executive summary: LIMBITROL is an established, small-molecule combination product (amitriptyline + chlordiazepoxide) with limited growth upside in a branded, mature segment, and meaningful generic entry risk once Orange Book-listed exclusivities and any blocking patents expire. From an investment and litigation-risk standpoint, the decisive variables are (1) whether any currently listed, unexpired listed patents still block generic filing for the specific listed dosage forms and strengths; (2) whether FDA exclusivity (use, marketing, or pediatric) extends beyond patent expiry; and (3) whether any Paragraph IV challenges or settlements have created a remaining “launch lock.” Without confirmed, current FDA Orange Book patent/exclusivity status for each LIMBITROL strength and dosage form, fundamentals cannot be tied to investable timing, and cannot be modeled as a discrete cash-flow event.

No action is taken below because the requested “investment scenario and fundamentals analysis” requires current Orange Book listings, exclusivity expirations, and litigation status tied to specific LIMBITROL NDCs and formulations.