Matching study design to prescribing intention: The prevalent new-user design for studying abuse-deterrent formulations of opioids.

PURPOSE: In drug studies, research designs requiring no prior exposure to certain drug classes may restrict important populations. Since abuse-deterrent formulations (ADF) of opioids are routinely prescribed after other opioids, choice of study design, identification of appropriate comparators, and addressing confounding by "indication" are important considerations in ADF post-marketing studies. METHODS: In a retrospective cohort study using claims data (2006-2018) from a North Carolina private insurer [NC claims] and Merative MarketScan [MarketScan], we identified patients (18-64 years old) initiating ADF or non-ADF extended-release/long-acting (ER/LA) opioids. We compared patient characteristics and described opioid treatment history between treatment groups, classifying patients as traditional (no opioid claims during prior six-month washout period) or prevalent new users. RESULTS: We identified 8415 (NC claims) and 147 978 (MarketScan) ADF, and 10 114 (NC claims) and 232 028 (MarketScan) non-ADF ER/LA opioid initiators. Most had prior opioid exposure (ranging 64%-74%), and key clinical differences included higher prevalence of recent acute or chronic pain and surgery among patients initiating ADFs compared to non-ADF ER/LA initiators. Concurrent immediate-release opioid prescriptions at initiation were more common in prevalent new users than traditional new users. CONCLUSIONS: Careful consideration of the study design, comparator choice, and confounding by "indication" is crucial when examining ADF opioid use-related outcomes.

Assessing Abuse-Deterrent formulations utilizing Ion-Exchange resin complexation processed via Twin-Screw granulation for improved safety and effectiveness.

Opioid misuse is a public health crisis in the United States. In response, the FDA has approved drug products with abuse-deterrent features to reduce the risk of prescription opioid abuse. Abuse-deterrent formulations (ADFs) typically employ physical or chemical barriers or incorporate agonist-antagonist combinations as mechanisms to deter misuse. This study aims to assess the impact of abuse-deterrent properties, specifically ion-exchange resin complexation as a chemical barrier, on a model drug, promethazine hydrochloride (PMZ) tablets. Various formulations were developed through twin-screw wet granulation (TSWG) followed by twin-screw melt granulation (TSMG). In the TSWG process, the drug interacts with the resin through an exchange reaction, forming a drug-resin complex. Additionally, the study explored factors influencing the complex formation between the drug and resin, using the drug loading status as an indicator. DSC and ATR studies were carried out to confirm the formation of the drug-resin complex. Subsequently, hot melt granulation was employed to create a matrix tablet incorporating Kollidon® SR and Kollicoat® MAE 100P, thereby enabling sustained release properties. The drug-resin complex embedded in the matrix effectively deters abuse through methods like smoking, snorting, or parenteral injection, unless the drug can be extracted. In order to assess this, solvent extraction studies were conducted using an FDA-recommended solvents, determining the potential for abuse. Further investigations involved dissolution tests in change-over media, confirming the extended-release properties of the formulation. Results from dissolution studies comparing the ground and intact tablets provided positive evidence of the formulation's effectiveness in deterring abuse. Finally, alcohol-induced dose-dumping studies were conducted in compliance with FDA guidelines, concluding that the formulation successfully mitigates dose dumping in the presence of alcohol.

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.

Evaluation of tableting performance of Poly (ethylene oxide) in abuse-deterrent formulations using compaction simulation studies.

Poly (ethylene oxide) (PEO) has been widely used in abuse-deterrent formulations (ADFs) to increase tablet hardness. Previous studies have shown that formulation variables such as processing conditions and particle size of PEO can affect ADF performance in drug extraction efficiency. This work aims to understand the effect of PEO grades and sources on the compaction characteristics of model ADFs. PEOs from Dow Chemical and Sumitomo Chemical with different molecular weights were examined using a Styl'One compaction simulator at slow, medium, and fast tableting speeds. Particle-size distribution, thermal behavior, tabletability, compressibility using the Heckel model, compactibility, and elastic recovery were determined and compared between the neat PEOs and model ADFs. Multivariate linear regression was performed to understand the effect of compression conditions and PEO grades and sources. Our results show that neat PEOs with high molecular weight exhibit high tabletability. The source of neat PEOs contributes to the difference in tabletability, out-die compressibility, compactibility, and elastic recovery. However, the influence of the PEO source on tabletability and compactibility decreases after adding the model drug. In our model ADFs, tablets using PEOs with high molecular weight have high crushing strength, and tablets using PEOs from Dow Chemical display low elastic recovery.

Opioid analgesia: recent developments.

PURPOSE OF REVIEW: Opioids are potent drugs for the treatment of severe pain, but they are burdened by detrimental side-effects, such as respiratory depression, addiction, sedation and constipation. Their clinical application is undisputed in acute (e.g. perioperative) and cancer pain, but their use in chronic nonmalignant pain has met increasing scrutiny and has contributed to the opioid crisis. Thus, novel analgesics with reduced side-effects are badly needed. RECENT FINDINGS: Current research topics include enkephalinase inhibitors, allosteric and multivalent ligands, biased opioid receptor signaling and selective activation of peripheral opioid receptors in injured tissues. SUMMARY: Opioids still appear to be most promising among current approaches in the development of analgesics. Basic knowledge about pathophysiology of clinical pain and novel insights in pharmacology suggest that the most interesting perspectives are augmenting endogenous opioid actions and selectively targeting peripheral opioid receptors. The latter approach is additionally supported by evidence from clinical studies. Some biased, multivalent and peripherally selective agonists have advanced to phase III trials, but novel drugs have not become available for clinical application. Future strategies in analgesic drug development might include public-private partnerships and nonprofit pharmaceutical companies, as exemplified by the AIDS crisis and proposals to combat antibiotic resistance.

The impact of the abuse-deterrent reformulation of extended-release OxyContin on prescription pain reliever misuse and heroin initiation.

The introduction of abuse-deterrent OxyContin in 2010 was intended to reduce its misuse by making it more tamper resistant. However, some studies have suggested that this reformulation might have had unintended consequences, such as increases in heroin-related deaths. We used the 2005-2014 cross-sectional U.S. National Survey on Drug Use and Health to explore the impact of this reformulation on intermediate outcomes that precede heroin-related deaths for individuals with a history of OxyContin misuse. Our study sample consisted of adults who misused any prescription pain reliever prior to the reformulation of OxyContin (n = 81,400). Those who misused OxyContin prior to the reformulation were considered the exposed group and those who misused other prescription pain relievers prior to the reformulation were considered the unexposed group. We employed multivariate logistic regression under a difference-in-differences framework to examine the effect of the reformulation on five dichotomous outcomes: prescription pain reliever misuse; prescription pain reliever use disorder; heroin use; heroin use disorder; and heroin initiation. We found a net reduction in the odds of prescription pain reliever misuse (OR:0.791, p < 0.001) and heroin initiation (OR:0.422, p = 0.011) after the reformulation for the exposed group relative to the unexposed group. We found no statistically significant effects of the reformulation on prescription pain reliever use disorder (OR: 0.934, p = 0.524), heroin use (OR: 1.014p = 0.941), and heroin use disorder (OR: 1.063, p = 0.804). Thus, the reformulation of OxyContin appears to have reduced prescription pain reliever misuse without contributing to relatively greater new heroin use among those who misused OxyContin prior to the reformulation.

Assessing Drug Release from Manipulated Abuse Deterrent Formulations.

There is a need to develop in vitro dissolution methods that discriminate for particle size of the manipulated abuse deterrent formulation (ADF) and that can be used for in vivo predictive models since dissolution methods developed for intact formulation might not be suitable for manipulated ones. A vertical diffusion cell (VDC) and United States Pharmacopeia (USP) Apparatus 1, 2, and 4 were evaluated for measuring the dissolution of intact and manipulated metoprolol succinate tablets with abuse deterrent-like properties. These tablets were physically manipulated to produce fine (106-500 µm) and coarse (500-1000 µm) powder samples. The VDC method was not able to discriminate the effect of particle size on drug release with varied stirring rate (200 to 800 rpm), molecular weight cut-off (MWCO, 3-5 kDa to 12-14 kDa) of the diffusion membrane, or composition and ionic strength (0.45% and 0.9%) of receiver medium. Standard and modified USP Apparatus 1 and 2 methods were assessed; however, large variations (RSD > 20%) were observed with USP Apparatus 1 for manipulated product dissolution and floating powder samples caused failure of auto-sampling when using standard USP Apparatus 2. For the USP Apparatus 4 dissolution method, packing configuration (1, 3, 8 layers and blend), ionic strength of dissolution medium (0.017, 0.077, and 0.154 M additional NaCl), and flow rate (4, 8, 16 mL/min) were studied to discriminate the effect of particle size on release. The USP Apparatus 4 dissolution method was optimized by using a packaging configuration of 8 layers with 8 mL/min flow rate which exhibited low variability and complete drug release and it could be used for in vivo predictive models. The dissolution method variables can be optimized for a specific product for desirable reproducibility and discriminatory power when using USP Apparatus 4.

Nonclinical safety assessment of PF614: A novel TAAP prodrug of oxycodone for chronic pain indication.

PF614, a novel trypsin activated abuse protection (TAAP) prodrug of oxycodone, is being studied as chronic pain analgesic with extended release and abuse resistant properties. A series of nonclinical safety studies were conducted to support PF614 introduction to clinical trials. Ames assays (PF614 and its metabolites), comet assay (PF614 ≤ 50 mg/kg/day oral gavage in rats) and micronucleus assay (PF614 ≤ 175 mg/kg/day oral gavage in rats) were negative. hERG assay IC50 for PF614 was ≥300 µM. PF614 (0.1 and 10 µM) showed a low permeability in Caco-2 cells (≤1.17 x 10-6 cm/s) and was not a P-gp or BCRP substrate or inhibitor. The mean percent unbound PF614 among all concentrations in plasma ranged from 91.2 to 98.4, 79.4 to 100, and 52.9-79.9% in rat, dog, and human, respectively. Also, PF614 was metabolically stable in rat, dog, and human hepatocytes with no metabolites identified. Safety pharmacology study in dog indicated moderately lower heart rate at ≥ 2 mg/kg oral gavage doses. Toxicity studies of PF614 in rat and dog with daily oral doses of 25 and 18 mg/kg, respectively, for 14 Days were well tolerated with favorable safety profile supporting its further clinical evaluation.

Opioid addiction, diversion, and abuse in chronic and cancer pain.

PURPOSE OF REVIEW: The primary cause of overdose death in the United States is related to pharmaceutical opioids. A few particular populations that struggle with adverse outcomes related to opioid abuse are those in palliative care, those with chronic pain, and those receiving pain treatments secondary to cancer or chemotherapy. RECENT FINDINGS: There have been massive efforts to decrease the use of opioid abuse in patient care in a gestalt manner, but palliative care provides unique challenges in applying these reduction tactics used by other specialties. SUMMARY: We explore behavioral interventions, provider education, alternative pain management techniques, postmarketing surveillance, and abuse-deterrent formulas as emerging methods to counteract opioid abuse in these populations.