LIMITX Technology

LIMITX Technology is intended to address an oral Excessive Tablet Abuse (ETA) or accidental consumption of multiple tablets and provide a margin of safety during accidental over-ingestion of tablets. LIMITX is also expected to exhibit barriers to abuse by snorting and injection.


LTX-03, an immediate-release hydrocodone bitartrate with acetaminophen tablet, is our lead LIMITX development program.

Previously, we have run two exploratory human pharmacokinetic studies, AP-LTX-400 & AP-LTX-401, on LTX-04P. These studies demonstrated:

  • we have too much buffer ingredient in a single tablet so that the micro-particles are not completely and immediately releasing all of the drug even at a single tablet
  • up to a 65% reduction in maximum plasma concentration (Cmax) when multiple tablets are ingested.

We are in the process of commencing Study AP-LTX-300 (Study 300), the first study for LTX-03 which will be a buffer dose ranging study. This study will include an active component that will include 10mg of hydrocodone bitartrate micro-particles and 325mg of acetaminophen. The active component will not contain any buffering capacity. We are also producing a buffering component which will have a fraction of the buffering capacity that was used in previous Studies 401 & 401 for product LTX-04. For this study, we will encapsulate the active component with an incremental number of buffering units. Subjects in the first group of this study will be placed into one of seven subgroups and will be administered with either no buffering units or up to 5 buffering units. The second group will only be administered an encapsulated commercially available reference product containing 10mg of hydrocodone bitartrate and 325mg of acetaminophen as a positive control. Our goal in this study is to identify the highest buffer level that allows for a full release of hydrocodone at a single tablet dose relative to the positive control before the LIMITX buffering effect is observed.

This study is expected to commence in September 2017 with top-line results expected in October 2017. This should guide us on the final formulation for LTX-03 tablets which will combine the hydrocodone micro-particles, acetaminophen, and buffer ingredients into a single tablet. Once completed, we will than progress to identifying a commercial manufacturer so that we may finalize the formulation which will be required for all NDA development work.