Company: SCLXW
Filing Date: 2025-08-04
Form Type: S-1
Source: 0001193125-25-172703
Chunk: 233

Company: Scilex Holding Co
Filing Date: 2025-08-04
Form: S-1
Chunk 233
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 and satisfaction. In draft guidance issued in July 2021, the FDA recommended that developers of topical and transdermal delivery systems (“TDSs”) conduct studies to characterize the adhesion performance of the product with suggested data requirements. Likewise, the FDA issued a draft guidance in October 2018 outlining the adhesion data requirements for generic TDSs. This guidance, along with Scilex’s past experience with regulatory agencies, shows the FDA’s interest and the importance of adhesion performance of these products. There are also

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dermal safety requirements that force developers to carefully balance adhesion performance against dermal safety. ZTlido is the first TDS product approved by the FDA that was able to demonstrate the targeted adhesion performance with an overall benign dermal safety profile.

The following figure depicts data derived from FAERS as of December 31, 2023:

For many of the competing lidocaine patches, a common drawback is the usage of hydrogel technology that limits the overall pharmaceutical efficiency of the product, requiring more total drug to be loaded into the patch to deliver a sufficient amount of drug to achieve a therapeutic effect. For example, Lidoderm has a drug load of 700 mg drug but only delivers 3± 2% of that drug load. Consequently, adhesive thickness must be increased in order to have a drug load sufficient to deliver a therapeutic dose of drug to the skin. As adhesive thickness increases, the product’s pliability can be compromised to the extent that the patch loses adhesion as the skin moves and wrinkles through normal patient activity. The weight of the hydrogel patches (largely due to high water content) further contributes to the challenge in maintaining adhesion.

The greater drug load also poses a risk of accidental exposure. For example, with a bioavailability of 3 ± 2% of the 700 mg drug load for Lidoderm, there is over 650 mg of drug remaining on the patch at the end of the 12-hour administration period, as captured in a bolded warning on the product label. If improperly disposed of, the residual drug poses the potential risk to children, pets and others of accidental exposure to a toxic amount of lidocaine, although we believe the risk with this formulation has not been evaluated.

In addition to prescription lidocaine patches, there are commercially-available OTC topical lidocaine products in the market, but none of these OTC products have been reviewed or approved by the FDA. Notably in