Optimal dose of buprenorphine in opioid use disorder treatment: a review of pharmacodynamic and efficacy data.

Context: There is currently no consensus regarding optimal dose or dose-range of buprenorphine (BUP) for treatment of opioid use disorder (OUD).Objective: To elucidate the relationship between BUP dose and opioid receptor blockade, retention in treatment and illicit opioid drug use.Methods: Systematic review of the scientific literature through searches in the databases MEDLINE and PubMed.Results: The review of the opioid receptor blockade studies did not find evidence that a daily sublingual (SL) BUP tablet dose higher than 16 mg confers added blockade benefit, while doses under 8 mg are insufficient to produce opioid receptor blockade. The data are inconclusive regarding the relative effectiveness of an 8 mg SL BUP tablet dose versus a 16 mg SL BUP tablet dose in terms of opioid receptor blockade. The review did not establish any clear relationship between BUP dose and treatment retention or illicit opioid use.Conclusions: The BUP dose in treatment of OUD should be individualized based on a continuous clinical benefit-risk assessment. Further research is needed to better understand the relationship between dose and efficacy over time in patients with this complex disorder.

Interfacial properties of POPC/GDO liquid crystalline nanoparticles deposited on anionic and cationic silica surfaces.

Reversed lipid liquid crystalline nanoparticles (LCNPs) of the cubic micellar (I2) phase have high potential in drug delivery applications due to their ability to encapsulate both hydrophobic and hydrophilic drug molecules. Their interactions with various interfaces, and the consequences for the particle structure and integrity, are essential considerations in their effectiveness as drug delivery vehicles. Here, we have studied LCNPs formed of equal fractions of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and glycerol dioleate in the presence of different fractions of the stabilizer Polysorbate 80. We have used a combination of ellipsometry, quartz crystal microbalance with dissipation monitoring and neutron reflectometry to reveal the structure and composition of the adsorbed layer on both anionic silica and cationic (aminopropyltriethoxysilane) silanized surfaces. For both types of surfaces, there is a spread near-surface layer comprising lipid and polymer as well as a sparse coverage of intact particles. The composition of the near-surface layer is very close to that of the particles, in contrast to the lipid bilayer observed with related systems. The interaction is stronger for cationic than anionic surfaces, which is rationalized in terms of the negative zeta potential of the LCNPs. The work shows that the attachment of and spreading from LCNPs is influenced by the properties of the surface, the internal structure, composition and stability of the particles as well as the nature of the stabilizer.

Octreotide s.c. depot provides sustained octreotide bioavailability and similar IGF-1 suppression to octreotide LAR in healthy volunteers.

AIMS: The aim was to assess the pharmacokinetics, pharmacodynamics, safety and tolerability of octreotide subcutaneous (s.c.) depot, a novel octreotide formulation. METHODS: This was a phase I, randomized, open label study. After a single dose of octreotide immediate release (IR) 200 µg, subjects were randomized to one of eight groups to receive three monthly injections of octreotide s.c. depot A 10, 20 or 30 mg, B 30 mg, C 10, 20 or 30 mg or long acting octreotide (octreotide LAR) 30 mg. RESULTS: One hundred and twenty-two subjects were randomized. For all depot variants, onset of octreotide release was rapid and sustained for up to 4 weeks. The relative octreotide bioavailability of depot variants vs. octreotide IR ranged from 0.68 (90% confidence interval [CI] 0.61, 0.76) to 0.91 (90% CI 0.81, 1.02) and, vs. octreotide LAR, was approximately four- to five-fold greater: 3.97 (90% CI 3.35, 4.71) to 5.27 ng ml(-1) h (90% CI 4.43, 6.27). All depot variants showed relatively rapid initial reductions of insulin-like growth factor 1 (IGF-1) compared with octreotide LAR. A trend of octreotide dose dependence was also indicated from the plasma concentrations and suppression of IGF-1. Maximum inhibition of IGF-1 at steady-state was highest for depot B and C. All depot treatments were well tolerated. The most frequent adverse events were gastrointestinal related. CONCLUSIONS: Octreotide s.c. depot provides greater octreotide bioavailability with a more rapid onset and stronger suppression of IGF-1 than octreotide LAR in healthy volunteers.

Structural effects of the dispersing agent polysorbate 80 on liquid crystalline nanoparticles of soy phosphatidylcholine and glycerol dioleate.

Well-defined, stable and highly structured I2 (Fd3̅m) liquid crystalline nanoparticles (LCNP) of 50/50 (wt/wt) soy phosphatidylcholine (SPC)/glycerol dioleate (GDO), can be formed by using a low fraction (5-10 wt%) of the dispersing polymeric surfactant polyoxyethylene (20) sorbitan monooleate (polysorbate 80 or P80). In the present study we used small angle neutron scattering (SANS) and deuterated P80 (d-P80) to determine the location and concentration of P80 within the LCNP and small angle X-ray scattering (SAXS) to reveal the internal structure. SANS data suggests that some d-P80 already penetrates the particle core at 5%. However, the content of d-P80 is still low enough not to significantly change the internal Fd3̅m structure of the LCNP. At higher fractions of P80 a phase separation occurs, in which a SPC and P80 rich phase is formed at the particle surface. The surface layer becomes gradually richer in both solvent and d-P80 when the surfactant concentration is increased from 5 to 15%, while the core of the particle is enriched by GDO, resulting in loss of internal structure and reduced hydration. We have used neutron reflectometry to reveal the location of the stabiliser within the adsorbed layer on an anionic silica and cationic (aminopropyltriethoxysilane (APTES) silanized) surface. d-P80 is enriched closest to the supporting surface and slightly more so for the cationic APTES surface. The results are relevant not only for the capability of LCNPs as drug delivery vehicles but also as means of preparing functional surface coatings.

Bioadhesive lipid compositions: self-assembly structures, functionality, and medical applications.

Lipid-based liquid crystalline compositions of phospholipids and diglycerides have unique bioadhesive properties with several medical applications, as exemplified by a lipid-based medical device indicated for management and relief of intraoral pain. The present paper describes the relation between self-assembly properties of phosphatidyl choline (PC) and glycerol dioleate (GDO) mixtures in the presence of aqueous fluids and functional attributes of the system, including: film formation and bioadhesion, intraoral coverage, acceptance by patients, and potential as a drug delivery system. The phase behavior of PC/GDO was characterized using synchrotron small-angle X-ray scattering. Functional properties, including the presence of study formulations at intraoral surfaces, ease of attachment, taste, and degree of and intraoral pain, were assessed in a crossover clinical pilot study in head and neck cancer patients. An optimum in functional properties was indicated for formulations with a PC/GDO weight ratio of about 35/65, where the lipids form a reversed cubic liquid crystalline micellar phase structure (Fd3m space group) over the relevant temperature range (25-40 °C).

Treatment of oral mucositis pain following radiation therapy for head-and-neck cancer using a bioadhesive barrier-forming lipid solution.

PURPOSE: CAM2028, a vehicle that forms a bioadhesive lipid barrier when applied to the oral mucosa, was developed as a carrier system for local delivery of benzydamine, an NSAID used for pain relief in oral mucositis. This trial compared the analgesic effect of CAM2028 plus benzydamine (CAM2028-benzydamine) with unmedicated CAM2028 (CAM2028-control) for the treatment of oral mucositis in patients with head-and-neck cancer. METHODS: Thirty-eight study participants were enrolled during their 3rd to 4th week of radiation therapy. Participants were required to have symptomatic oral mucositis (WHO Grade 2 or above) at screening and pain scores of at least 6 on an 11-point Likert scale at screening and on each day before treatment with study medication. After undergoing radiation, patients were administered a single dose of CAM2028-control or CAM2028-benzydamine 2 days apart, in a randomized crossover fashion. Pain was assessed over the following 8 h. RESULTS: With both treatments, patients experienced a mean 40 % decrease in pain intensity at 6 h (the primary study endpoint). Both treatments resulted in significant pain relief within 5 min of application that was evident during the entire 8-h assessment period. There was no difference in pain relief between the two interventions at any time point. Both treatments were safe and well tolerated. CONCLUSIONS: CAM2028-benzydamine and CAM2028-control were both efficacious in reducing pain in patients with oral mucositis related to radiation therapy for head-and-neck cancer. Analgesic effects of both medications were immediate, clinically significant, and persistent for up to 8 h.

Pharmacokinetics and pharmacodynamics of a pasireotide subcutaneous depot (CAM4071) and comparison with immediate and long-acting release pasireotide.

PURPOSE: To assess the pharmacokinetics, pharmacodynamics, safety and tolerability of subcutaneous depot CAM4071, a novel, ready-to-use pasireotide formulation. METHODS: This was a phase 1, randomised, open-label study in healthy volunteers. After a single 600 µg dose of pasireotide immediate release (IR), participants were randomised to one of eight groups to receive either a CAM4071 upper thigh (5, 10, 20, 40 or 80 mg) or buttock (20 mg) injection or multiple pasireotide IR 900 µg upper thigh injections twice daily or a single pasireotide long-acting release (LAR) 60 mg intramuscular buttock injection. RESULTS: Ninety-four participants were randomised. For all CAM4071 doses, initial pasireotide release was relatively rapid compared to pasireotide LAR and sustained over the 2-month observation period, with a slow decay in plasma concentrations. CAM4071 maximum plasma concentrations increased slightly greater than dose proportionally; area under the curve extrapolated to infinity increased approximately dose proportionally. Relative bioavailability of pasireotide for different doses of CAM4071 versus pasireotide IR 600 µg ranged from 0.752 (90% confidence interval [CI]: 0.58, 0.98) to 1.68 (1.32, 2.14), and versus pasireotide LAR: 0.517 (0.37, 0.72) to 1.15 (0.84, 1.58). CAM4071 doses >5 mg exhibited rapid initial reductions of insulin-like growth factor 1 (IGF-1) compared to pasireotide LAR. Maximum IGF-1 inhibition was greatest for CAM4071 80 mg. CAM4071 injections ≤40 mg were well tolerated and comparable with currently available pasireotide formulations. CONCLUSION: CAM4071 provided long-acting release of pasireotide over at least one month, with high bioavailability and onset and duration of IGF-1 suppression similar to pasireotide LAR. TRIAL REGISTRATION: EudraCT: 2014-003783-20.

Extended-Release Injection vs Sublingual Buprenorphine for Opioid Use Disorder With Fentanyl Use: A Post Hoc Analysis of a Randomized Clinical Trial.

Importance: Fentanyl has exacerbated the opioid use disorder (OUD) and opioid overdose epidemic. Data on the effectiveness of medications for OUD among patients using fentanyl are limited. Objective: To assess the effectiveness of sublingual or extended-release injection formulations of buprenorphine for the treatment of OUD among patients with and without fentanyl use. Design, Setting, and Participants: Post hoc analysis of a 24-week, randomized, double-blind clinical trial conducted at 35 outpatient sites in the US from December 2015 to November 2016 of sublingual buprenorphine-naloxone vs extended-release subcutaneous injection buprenorphine (CAM2038) for patients with OUD subgrouped by presence vs absence of fentanyl or norfentanyl in urine at baseline. Study visits with urine testing occurred weekly for 12 weeks, then 6 times between weeks 13 and 24. Data were analyzed on an intention-to-treat basis from March 2022 to August 2023. Intervention: Weekly and monthly subcutaneous buprenorphine vs daily sublingual buprenorphine-naloxone. Main Outcomes and Measures: Retention in treatment, percentage of urine samples negative for any opioids (missing values imputed as positive), percentage of urine samples negative for fentanyl or norfentanyl (missing values not imputed), and scores on opiate withdrawal scales and visual analog craving scales. Results: Of 428 participants, 123 (subcutaneous buprenorphine, n = 64; sublingual buprenorphine-naloxone, n = 59; mean [SD] age, 39.1 [10.8] years; 75 men [61.0%]) had evidence of baseline fentanyl use and 305 (subcutaneous buprenorphine, n = 149; buprenorphine-naloxone, n = 156; mean [SD] age, 38.1 [11.1] years; 188 men [61.6%]) did not have evidence of baseline fentanyl use. Study completion was similar between the fentanyl-positive (60.2% [74 of 123]) and fentanyl-negative (56.7% [173 of 305]) subgroups. The mean percentage of urine samples negative for any opioid were 28.5% among those receiving subcutaneous buprenorphine and 18.8% among those receiving buprenorphine-naloxone in the fentanyl-positive subgroup (difference, 9.6%; 95% CI, -3.0% to 22.3%) and 36.7% among those receiving subcutaneous buprenorphine and 30.6% among those receiving buprenorphine-naloxone in the fentanyl-negative subgroup (difference, 6.1%; 95% CI, -1.9% to 14.1%), with significant main associations of baseline fentanyl status and treatment group. In the fentanyl-positive subgroup, the mean percentage of urine samples negative for fentanyl during the study was 74.6% among those receiving subcutaneous buprenorphine vs 61.9% among those receiving sublingual buprenorphine-naloxone (difference, 12.7%; 95% CI, 9.6%-15.9%). Opioid withdrawal and craving scores decreased rapidly after treatment initiation across all groups. Conclusions and Relevance: In this post hoc analysis of a randomized clinical trial of sublingual vs extended-release injection buprenorphine for OUD, buprenorphine appeared to be effective among patients with baseline fentanyl use. Patients with fentanyl use had fewer opioid-negative urine samples during the trial compared with the fentanyl-negative subgroup. These findings suggest that the subcutaneous buprenorphine formulation may be more effective at reducing fentanyl use. Trial Registration: ClinicalTrials.gov Identifier: NCT02651584.

Pharmacokinetic-pharmacodynamic analysis of drug liking blockade by buprenorphine subcutaneous depot (CAM2038) in participants with opioid use disorder.

Buprenorphine is used to treat opioid use disorder (OUD). Weekly and monthly subcutaneous long-acting buprenorphine injections (CAM2038) provide more stable buprenorphine plasma levels and reduce the treatment burden, misuse, and diversion associated with sublingual transmucosal buprenorphine formulations. To characterize the pharmacokinetic/pharmacodynamic (PK/PD) relationship, a maximum inhibition (Imax) model was developed relating CAM2038 buprenorphine plasma concentration to drug liking maximum effect (Emax) visual analog scale (VAS; bipolar) score after intramuscular hydromorphone administration. Data included time-matched observations of buprenorphine plasma concentration and drug liking Emax VAS score after hydromorphone 18 mg administration in 47 non-treatment-seeking adults with moderate to severe OUD in a phase 2 study. Analysis used non-|linear mixed-effects modeling (NONMEM®). The final Imax model adequately described the PK/PD relationship between buprenorphine plasma concentration and drug liking Emax VAS score. Simulations showed drug liking was effectively blocked at low buprenorphine plasma concentrations (0.4 ng/mL) where the upper 95% confidence interval of the drug liking Emax VAS score was below the pre-defined 11-point complete blockade threshold. The buprenorphine plasma concentration required to achieve 90% of the maximal effect (IC90) of drug liking was 0.675 ng/mL. Interindividual variability in responses to buprenorphine was observed; some participants experienced fluctuating responses, and a few did not achieve drug liking blockade even with higher buprenorphine plasma concentrations. This affirms the need to individualize treatment and titrate doses for optimal treatment outcomes. PK/PD models were also developed for desire to use VAS and Clinical Opiate Withdrawal Scale (COWS) scores, with results aligned to those for drug liking.

Methodology of the SORENTO clinical trial: a prospective, randomised, active-controlled phase 3 trial assessing the efficacy and safety of high exposure octreotide subcutaneous depot (CAM2029) in patients with GEP-NET.

BACKGROUND: The current standard of care (SoC) for the initial treatment of unresectable or metastatic well-differentiated gastroenteropancreatic neuroendocrine tumours (GEP-NET) requires initiation of first-generation somatostatin receptor ligand (SRL) therapy, octreotide and lanreotide, which provide safe and efficacious tumour/symptom control in most patients. However, disease progression can occur with SoC SRL treatment and the optimal dose response of SRL remains unknown. Octreotide subcutaneous depot (CAM2029) is a novel, long-acting, high-exposure formulation that has shown greater bioavailability and improved administration than octreotide long-acting release (LAR) with a well-tolerated safety profile. Retrospective data have highlighted a potential benefit of high-exposure SRL for improved disease control in patients who did not adequately respond to the current SoC SRL treatment. This trial will investigate the efficacy and tolerability of CAM2029 compared to the current SoC, including octreotide LAR and lanreotide autogel (ATG). METHODS: SORENTO is a prospective, multicentre, randomised, active-controlled, open-label phase 3 trial aiming to demonstrate superiority of treatment with 20 mg octreotide subcutaneous depot (CAM2029) every 2 weeks (Q2W) compared to treatment with the Investigator's choice of SRL therapy at standard doses for tumour control (octreotide LAR 30 mg or lanreotide ATG 120 mg every 4 weeks [Q4W]) as assessed by progression-free survival (PFS) in approximately 300 patients with unresectable/metastatic and well-differentiated GEP-NET. Upon confirmation of disease progression (determined by a Blinded Independent Review Committee [BIRC] and defined as per RECIST 1.1), patients may enter an open-label extension treatment period with once weekly dosing, to investigate the effects of higher frequency dosing. Overall survival follow-up will end a maximum of 2 years after primary analysis. The primary endpoint will be analysed after 194 confirmed PFS events. DISCUSSION: This is the first trial investigating the efficacy of CAM2029 versus SoC SRL therapy using a head-to-head, superiority trial design. It is expected to be the first trial to investigate the efficacy of increased dosing frequency of a high-exposure SRL. A BIRC will limit bias and measurement variability and ensure high-quality efficacy data. Additionally, inclusion of patients with well-differentiated Grade 3 NET may elucidate treatment strategies for this rarely investigated patient population. TRIAL REGISTRATION: ClinicalTrials.gov NCT05050942. Registered on 21st September 2021.

Population Pharmacokinetic Analysis Supports Initiation Treatment and Bridging from Sublingual Buprenorphine to Subcutaneous Administration of a Buprenorphine Depot (CAM2038) in the Treatment of Opioid Use Disorder.

BACKGROUND AND OBJECTIVE: In treating opioid use disorder (OUD), subcutaneous (SC) extended-release buprenorphine (BPN) depots, e.g., CAM2038, have been shown to provide smaller and less frequent fluctuations in BPN plasma concentrations and pharmacodynamic responses, improve outcomes, reduce treatment burden, and lower risks of misuse and diversion compared to daily sublingual (SL) BPN. This analysis characterized the pharmacokinetics (PK) of BPN following intravenous and SL administration, and administration of SC CAM2038 weekly and monthly. METHODS: Pharmacokinetic data from two Phase 1 and two Phase 2 trials in healthy participants and participants with OUD, respectively, were used to develop a population PK model using non-linear mixed effects modelling. The analysis included data from 252 participants and 10,658 BPN observations. RESULTS: The disposition of BPN was best described by a three-compartment model with first-order elimination, and absorption of SL BPN and SC CAM2038 weekly and monthly by dual parallel absorption pathways. Model diagnostics indicated good predictive performance of BPN concentrations. Buprenorphine plasma concentration-time profiles were simulated for treatment initiation, switching from SL BPN to CAM2038 weekly and monthly, and tapering after interrupting treatment with CAM2038. Simulations predicted CAM2038 weekly and monthly doses that provided BPN plasma maximum concentration (Cmax) and trough concentration (Ctrough) values at steady state within those observed following SL BPN administration. CONCLUSIONS: This population PK model supports the use of CAM2038 doses as individualized treatment for OUD across different treatment stages, including initiation, switching from SL BPN according to established dose conversion schedules, and tapering. TRIAL REGISTRATIONS: ISRCTN41550730 (05/19/2014), ISRCTN24987553 (07/29/2014), NCT02611752 (11/23/2015), NCT02710526 (03/16/2016).

Adsorption of lipid liquid crystalline nanoparticles: effects of particle composition, internal structure, and phase behavior.

Controlling the interfacial behavior and properties of lipid liquid crystalline nanoparticles (LCNPs) at surfaces is essential for their application for preparing functional surface coatings as well as understanding some aspects of their properties as drug delivery vehicles. Here we have studied a LCNP system formed by mixing soy phosphatidylcholine (SPC), forming liquid crystalline lamellar structures in excess water, and glycerol dioleate (GDO), forming reversed structures, dispersed into nanoparticle with the surfactant polysorbate 80 (P80) as stabilizer. LCNP particle properties were controlled by using different ratios of the lipid building blocks as well as different concentrations of the surfactant P80. The LCNP size, internal structure, morphology, and charge were characterized by dynamic light scattering (DLS), synchrotron small-ange X-ray scattering (SAXS), cryo-transmission electron microscopy (cryo-TEM), and zeta potential measurements, respectively. With increasing SPC to GDO ratio in the interval from 35:65 to 60:40, the bulk lipid phase structure goes from reversed cubic micellar phase with Fd3m space group to reversed hexagonal phase. Adding P80 results in a successive shift toward more disorganized lamellar type of structures. This is also seen from cryo-TEM images for the LCNPs, where higher P80 ratios results in more extended lamellar layers surrounding the inner, more dense, lipid-rich particle core with nonlamellar structure. When put in contact with a solid silica surface, the LCNPs adsorb to form multilayer structures with a surface excess and thickness values that increase strongly with the content of P80 and decreases with increasing SPC:GDO ratio. This is reflected in both the adsorption rate and steady-state values, indicating that the driving force for adsorption is largely governed by attractive interactions between poly(ethylene oxide) (PEO) units of the P80 stabilizer and the silica surface. On cationic surface, i.e., silica modified with 3-aminopropltriethoxysilane (APTES), the slightly negatively charged LCNPs give rise to a very significant adsorption, which is relatively independent of LCNP composition. Finally, the dynamic thickness measurements indicate that direct adsorption of intact particles occurred on the cationic surface, while a slow buildup of the layer thickness with time is seen for the weakly interacting systems.

Boundary lubrication under water.

Boundary lubrication, in which the rubbing surfaces are coated with molecular monolayers, has been studied extensively for over half a century. Such monolayers generally consist of amphiphilic surfactants anchored by their polar headgroups; sliding occurs at the interface between the layers, greatly reducing friction and especially wear of the underlying substrates. This process, widespread in engineering applications, is also predicted to occur in biological lubrication via phospholipid films, though few systematic studies on friction between surfactant layers in aqueous environments have been carried out. Here we show that the frictional stress between two sliding surfaces bearing surfactant monolayers may decrease, when immersed in water, to as little as one per cent or less of its value in air (or oil). We attribute this to the shift of the slip plane from between the surfactant layers, to the surfactant/substrate interface. The low friction would then be due to the fluid hydration layers surrounding the polar head groups attached to the substrate. These results may have implications for future technological and biomedical applications.

Ordinary people, criminals, addicts and recreational users: Swedish court of law descriptions of persons sentenced for online drug purchases.

Background: The aim of this study was to analyze how Swedish courts describe persons sentenced for purchasing illicit drugs online. Methods: Qualitative analysis of naturally occurring data through 201 sentences that included 248 individuals sentenced for having purchased drugs online between January 1 2010 and January 1 2020. Results: The analysis resulted in the construction of four ideal types regarding the described characteristics of the sentenced persons; the ordinary person, the recreational user, the addict and the criminal. The courts operate with a notable dichotomy between traditional drug markets and online drug markets, that can be understood in relation to descriptions of Bourdieusian capital forms, specifically street capital and digital capital. Conclusion: Descriptions relating to street capital were of larger interest to the courts compared to digital capital, although there were examples of when the courts argued that uses of digital capital should be viewed as an aggravating circumstance. The courts largely held a dichotomous view of online and offline drug markets that focus on street-based criminality, which may have implications for how emerging digital drug markets are responded to by drug law enforcement and judicial systems.

Patient-Reported Outcomes of Treatment of Opioid Dependence With Weekly and Monthly Subcutaneous Depot vs Daily Sublingual Buprenorphine: A Randomized Clinical Trial.

Importance: Patient-reported outcomes in the treatment of opioid dependence may differ between subcutaneously administered depot buprenorphine and daily sublingual buprenorphine. Objective: To compare patient satisfaction between depot buprenorphine and sublingual buprenorphine in adult outpatients with opioid dependence. Design, Setting, and Participants: This open-label, randomized clinical trial was conducted among adult patients with opioid dependence at 6 outpatient clinical sites in Australia from October 2018 to September 2019. Data analysis was conducted from October 2019 to May 2020. Interventions: Participants were randomized to receive treatment with weekly or monthly depot buprenorphine or daily sublingual buprenorphine over 24 weeks. Main Outcomes and Measures: The primary end point was the difference in global treatment satisfaction, assessed by the Treatment Satisfaction Questionnaire for Medication (TSQM) version 1.4 (range, 0-100; higher score indicates greater satisfaction) at week 24. Secondary end points included other patient-reported outcomes, including quality of life, treatment burden, and health-related outcomes, as well as measures of opioid use, retention in treatment, and safety. Results: A total of 119 participants (70 [58.8%] men; mean [SD] age, 44.4 [10.5] years) were enrolled, randomized to, and received either depot buprenorphine (60 participants [50.4%]) or sublingual buprenorphine (59 participants [49.6%]). From the initial sample of 120, a participant (0.8%) in the sublingual buprenorphine group withdrew consent and did not receive study treatment. All participants were receiving sublingual buprenorphine when enrolled. The mean TSQM global satisfaction score was significantly higher for the depot group compared with the sublingual group at week 24 (mean [SE] score, 82.5 [2.3] vs 74.3 [2.3]; difference, 8.2; 95% CI, 1.7 to 14.6; P = .01). Improved outcomes were also observed for several secondary end points after treatment with depot buprenorphine (eg, mean [SE] treatment burden assessed by the Treatment Burden Questionnaire global score, on which lower scores indicate lower burden: 13.2 [2.6] vs 28.6 [2.5]; difference, -15.4; 95% CI, -22.6 to -8.2; P < .001). Thirty-nine participants (65.0%) in the depot buprenorphine group experienced 117 adverse drug reactions, mainly injection site reactions of mild intensity following subcutaneous administration, and 12 participants (20.3%) in the sublingual buprenorphine group experienced 21 adverse drug reactions. No participants withdrew from the trial medication or the trial due to adverse events. Conclusions and Relevance: In this study, participants receiving depot buprenorphine reported improved treatment satisfaction compared with those receiving sublingual buprenorphine. The results highlight the application of patient-reported outcomes as alternative end points to traditional markers of substance use in addiction treatment outcome studies. Trial Registration: anzctr.org.au Identifier: ANZCTR12618001759280.

Long-term safety of a weekly and monthly subcutaneous buprenorphine depot (CAM2038) in the treatment of adult out-patients with opioid use disorder.

AIMS: To assess the long-term safety of subcutaneous buprenorphine (CAM2038) weekly and monthly depots. DESIGN: Phase 3, open-label, observational, multi-centre 48-week trial (ClinicalTrials.gov NCT02672111). SETTING: Twenty-six out-patient sites (United States, United Kingdom, Hungary, Denmark, Sweden, Germany, Australia) between 14 December 2015 and 12 April 2017. PARTICIPANTS: Two hundred and twenty-eight adults with opioid use disorder; 227 received CAM2038 (37 initiated onto CAM2038 and 190 converted from sublingual buprenorphine). INTERVENTIONS: CAM2038 weekly (8, 16, 24 or 32 mg) or monthly (64, 96, 128 or 160 mg) with flexible dosing and individualized titration utilizing multiple CAM2038 weekly and monthly doses. MEASUREMENTS: Safety variables, urine toxicology samples and self-reported illicit opioid use were collected at each visit. Participants were administered a patient satisfaction survey at months 6 and 12, completed by 162 of 227 (71.4%) participants. FINDINGS: The study treatment period was completed by 167 of 227 (73.6%) participants. At least one treatment-emergent adverse event (TEAE) was reported by 143 of 227 (63.0%) participants, of whom 60 of 227 (26.4%) reported as being drug-related. Most of the TEAEs, reported by 128 of 227 (56.4%) of participants, were mild or moderate in intensity. Injection-site reactions were reported by 46 of 227 (20.3%) participants, with most [45 of 46 (97.8%)] reported as mild to moderate. Five participants (2.2%) discontinued the study drug due to a TEAE, two cases (0.9%) of which were injection-site-related. No serious adverse events were attributed to the study drug. Among those remaining in the study, the percentage of opioid-negative urine tests combined with self-reports was 63.0% (17 of 27) in new-to-treatment participants and 82.8% (111 of 134) for those converted from sublingual buprenorphine. Participants reported high levels of satisfaction with CAM2038. CONCLUSIONS: Subcutaneous buprenorphine delivered weekly or monthly (CAM2038) was well tolerated, with a systemic safety profile consistent with the known profile of sublingual buprenorphine. CAM2038 weekly and monthly was associated with high retention rates and low levels of illicit opioid use throughout this study.

Octreotide SC depot in patients with acromegaly and functioning neuroendocrine tumors: a phase 2, multicenter study.

PURPOSE: Octreotide SC depot is a novel, ready-to-use formulation administered via a thin needle. In a phase 1 study in healthy volunteers, this formulation provided higher bioavailability of octreotide with faster onset and stronger suppression of IGF-1 in healthy volunteers versus long-acting intramuscular (IM) octreotide. This phase 2 study evaluated the pharmacokinetics, efficacy, and safety of octreotide SC depot in patients with acromegaly and functioning NETs, previously treated with octreotide IM. METHODS: Adult patients with acromegaly or functioning NETs treated for ≥ 2 months with octreotide IM [10/20/30 mg every 4 weeks (q4w)] received the last dose of octreotide IM treatment in study period 0 and were randomized 28 days later to receive octreotide SC depot 10 mg q2w, or 20 mg q4w for 3 months (period 1). The primary objective was to characterize the PK profile of octreotide SC depot after each injection vs PK for octreotide IM (period 0). RESULTS: Twelve patients were randomized to receive octreotide SC depot 10 mg q2w (acromegaly n = 3; NET n = 1) or 20 mg q4w (acromegaly n = 4; NET n = 4). Plasma levels of octreotide were higher with octreotide SC depot as compared to octreotide IM. Adverse events were reported in 6 and 8 patients during period 0 and period 1, respectively; most common in period 1 were gastrointestinal disorders. CONCLUSION: Octreotide SC depot provided higher exposure (AUC) than octreotide IM, maintained biochemical control in patients with acromegaly and symptom control in patients with functioning NETs, and was well tolerated with a safety profile consistent with octreotide IM. CLINICALTRIALS. GOV IDENTIFIER: NCT02299089.

Distribution of reaction products in phospholipase A2 hydrolysis.

We have monitored the composition of supported phospholipid bilayers during phospholipase A(2) hydrolysis using specular neutron reflection and ellipsometry. Porcine pancreatic PLA(2) shows a long lag phase of several hours during which the enzyme binds to the bilayer surface, but only 5+/-3% of the lipids react before the onset of rapid hydrolysis. The amount of PLA(2), which resides in a 21+/-1 A thick layer at the water-bilayer interface, as well as its depth of penetration into the membrane, increase during the lag phase, the length of which is also proportional to the enzyme concentration. Hydrolysis of a single-chain deuterium labelled d(31)-POPC reveals for the first time that there is a significant asymmetry in the distribution of the reaction products between the membrane and the aqueous environment. The lyso-lipid leaves the membrane while the number of PLA(2) molecules bound to the interface increases with increasing fatty acid content. These results constitute the first direct measurement of the membrane structure and composition, including the location and amount of the enzyme during hydrolysis. These are discussed in terms of a model of fatty-acid mediated activation of PLA(2).

The lipolytic degradation of highly structured cubic micellar nanoparticles of soy phosphatidylcholine and glycerol dioleate by phospholipase A2 and triacylglycerol lipase.

The effects of different lipolytic enzymes on the structure of lipid liquid crystalline nano-particles (LCNP) have been investigated by cryogenic transmission electron microscopy (cryo-TEM) and synchrotron small angle X-ray diffraction (SAXD). Here we used highly structured cubic micellar (Fd3m) nanoparticles of 50/50 (wt%/wt%) soy phosphatidyl choline (SPC)/glycerol dioleate (GDO) as substrate. Two types of lipolytic enzymes were used, phospholipase A2 (PLA2) that catalyses degradation of the phospholipid component, SPC, and porcine pancreatic triacylglycerol lipase (TGL) that facilitate the hydrolysis of the diglyceride, GDO. Evolution of the structure was found to be very different and linked to specificity of the two types of enzymes. PLA2, which hydrolyses the lamellar forming component, SPC, induces a reversed micellar lipid phase, while TGL which hydrolysis the reverse phase forming compound, GDO, induces a lamellar phase.