In vitro test methods for evaluating high molecular weight polyethylene oxide polymer induced hemolytic and thrombotic potential

To combat opioid abuse, the U.S. Food and Drug Administration (FDA) released a comprehensive action plan to address opioid addiction, abuse, and overdose that included increasing the prevalence of abuse-deterrent formulations (ADFs) in opioid tablets. Polyethylene oxide (PEO) has been widely used as an excipient to deter abuse via nasal insufflation. However, changes in abuse patterns have led to unexpected shifts in abuse from the nasal route to intravenous injection. Case reports identify adverse effects similar to thrombotic thrombocytopenic purpura (TTP) syndrome following the intravenous (IV) abuse of opioids containing PEO excipient. Increased risk of IV opioid ADF abuse compared to clinical benefit of the drug led to the removal of one opioid product from the market in 2017. Because many generic drugs containing PEO are still in development, there is interest in assessing safety consistent with generic drug regulation and unintended uses. Currently, there are no guidelines or in vitro assessment tools to characterize the safety of PEO excipients taken via intravenous injection. To create a more robust excipient safety evaluation tool and to study the mechanistic basis of HMW PEO-induced TMA, a dynamic in vitro test system involving blood flow through a needle model has been developed.

Understanding syringeability and injectability of high molecular weight PEO solution through time-dependent force-distance profiles

Opioid medications play a vital role in treating moderate to severe pain. Unfortunately, many drug misusers and abusers attempt to alter the formulations or properties of these drugs by manipulation, (e.g., crushing, chewing, smoking, snorting, injecting). The intravenous (IV) route is most dangerous to abusers, as the drugs directly enter the circulatory system and produce intense euphoria. To obtain a full understanding of the impact of syringe factors (e.g., needle gauge size, needle length, syringe barrel size), on the ease of injection, we undertook a comprehensive assessment of syringeability and injectability of manipulated abuse-deterrent formulations (ADFs). A texture analyzer-based testing method was developed for the measurement of the resistance force of pulling, holding, and pushing phases of injections. Results showed that the finer needle gauge sizes required higher injection force to withdraw drug solutions. In addition, the syringed liquid volume was highly dependent on needle gauge size, holding time, and sample viscosity. In most cases, a lower needle gauge number and a longer holding time increased the syringed volume. Needle length was highly correlated to injection force (R² = 0.99). Using longer needles to inject drug solution requires greater force. Furthermore, large barrel size was correlated to pushing force (R² = 0.99); thus, increasing the difficulty of pushing the plunger of a large syringe with one hand. Finally, relationships between injection force, sample viscosity, and testing conditions were elucidated using a mathematical model, which could be used in the future to assess and predict injection force of solution samples.

PLA-PCL microsphere formulation to deter abuse of prescription opioids by smoking

Opioids are commonly prescribed across the United States (US) for pain relief, despite their highly addictive nature that often leads to abuse and overdose deaths. Abuse deterrent formulations (ADFs) for prescription opioids make the non-therapeutic use of these drugs more difficult and less satisfying. Although approximately one-third of surveyed abusers in the US reported smoking opioids, to our knowledge, no commercialized ADF effectively prevents opioid smoking. Here, we report a novel approach to deter smoking of a model prescription opioid drug, thebaine (THB), by using polymer blend microspheres (MS) comprising polylactic acid (PLA) and polycaprolactone (PCL). We utilized high-performance liquid chromatography (HPLC) and thermogravimetric analysis (TGA) to test the ability of PLA-PCL MS to limit the escape of vaporized THB. Additionally, we compared the abuse-deterrent potential of PLA-PCL MS to that of activated carbon (AC) and mesoporous silica (MPS), two materials with excellent drug-adsorbing properties. Our MS formulation was effective in reducing the amount of both active drug and thermal degradation products in the vapor generated upon heating of THB. These results support that PLA-PCL microspheres can be co-formulated in a tablet with common prescription opioids to deter their abuse via the smoking route.

Extended release pellets prepared by hot melt extrusion technique for abuse deterrent potential: Category-1 in-vitro evaluation

The objective of the present study was to develop extended-release (ER) hot-melt extruded (HME) abuse-deterrent pellets of acetaminophen, a model drug, by utilizing high molecular weight polyethylene oxide (PEO) and gelling agents (xanthan gum, guar gum, and gellan gum). The HME pellets were evaluated for their abuse-deterrence (AD) potential by Category-1 laboratory in-vitro evaluation parameters, including particle size reduction (PSR), small volume extraction, dissolution, viscosity, syringeability, and injectability. Further, the pellets were investigated for resistance to physical (crushing) and thermal (oven and microwave) manipulation to evaluate the strength of the AD properties. Physical manipulation studies demonstrated that the pellets were intact, extremely hard, and resistant to PSR and manipulation to bypass ER properties. Dissolution of all intact and physically manipulated pellets led to complete drug release within 8 h, and resistance to dose-dumping in 40% ethanol was observed. The drug extraction was <50% in 10 mL of ingestible and non-ingestible solvents under static, agitation, and thermal manipulation conditions with an incubation time of 30 min. The PEO/xanthan gum-based formulation showed higher viscosity, syringe and injection forces, and lower syringeable volume in all manipulation conditions compared with plain PEO pellets. These findings supported the AD potential of PEO and xanthan gum pellets against intravenous abuse.

Relative Oral Bioavailability of an Abuse-Deterrent, Immediate-Release Formulation of Oxycodone, Oxycodone ARIR in a Randomized Study

Introduction

Oxycodone ARIR is a novel oral, abuse-deterrent, immediate-release (IR) formulation with physical and chemical properties that deter misuse and abuse by non-oral routes. In this single-dose pharmacokinetic study, we assessed the relative bioavailability of oxycodone for Oxycodone ARIR and IR oxycodone, and the effect of food on Oxycodone ARIR following oral administration.

Methods

This open-label, randomized study in healthy adults compared the relative bioavailability of Oxycodone ARIR 30 mg to IR oxycodone 30 mg under fasted conditions, and Oxycodone ARIR under fed versus fasted conditions. Pharmacokinetic parameters included area under the concentration–time curve from time 0 to the last measured concentration (AUC_0–t) and the maximum oxycodone plasma concentration (C_max). Equivalence was determined using an analysis of variance of the least-squares means.

Results

Fifty-eight subjects completed the study. Under fasted conditions, AUC_0–t was 4% lower (90% CI 92.5–98.7%) and mean C_max was 14% lower (90% CI 78.8–94.3%) for Oxycodone ARIR versus IR oxycodone. AUC_0–t was 23% higher (90% CI 119.1–127.0%) and mean C_max was higher (90% CI 108.6–129.4%) when Oxycodone ARIR was administered in the fed versus fasted state. Common adverse events included nausea, headache, and dizziness.

Conclusion

In this single-dose pharmacokinetic evaluation, fasted Oxycodone ARIR 30 mg had similar bioavailability to and is expected to have the same efficacy and safety profile as IR oxycodone. When administered in the fed state, pharmacokinetic parameters were slightly higher; however, these differences were considered not clinically meaningful and show that Oxycodone ARIR can be administered with or without food.

Funding

This study was funded by Inspirion Delivery Sciences, LLC. Daiichi Sankyo, Inc. funded the journal’s article processing charges and open access fee.

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