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Purpose Drug sales facilitated through digital communication on the surface web and on darknet cryptomarkets have increased during the past two decades. This has resulted in an increase in drug law enforcement efforts to combat these markets and a subsequent increase in judicial sentencing of people selling drugs online. The aim of this study was to analyze how Swedish courts describe sentenced sellers and how the courts apply case law. Design/methodology/approach The empirical material consists of 71 sentencing documents produced by Swedish courts in cases of online drug selling between January 1, 2010 and January 1, 2020. In total, 99 sentenced persons occur in the documents. Using a qualitative research design, the authors analyzed the material through thematic text analysis. Findings Overall, in their descriptions of online drug sale operations, the courts’ characterizations of the concepts of street capital and digital capital show a dichotomy. These forms of capital are situationally described as both aggravating and mitigating aspects in the application of case law, indicating that it may be fruitful to view both street and digital capital as resources used on contemporary drug markets in general. Originality/value Very little research exists into how judicial systems describe and perceive the developing phenomenon of online drug sales. Using a relatively large sample from a decade of sentencing, the authors provide an analysis of how Swedish courts view and valuate capital forms in the online drugs trade.

Background/Aims Prostacyclin analogues, although effective treatment for systemic sclerosis (SSc)-related Raynaud’s phenomenon (RP), have the disadvantage of requiring intravenous or subcutaneous (SC) infusion. Treprostinil subcutaneous depot (CAM2043) is a novel extended-release SC formulation of treprostinil. The aim of this trial was to explore the effect of a single SC dose of CAM2043 on skin temperature (indirect measure of perfusion), as evaluated by thermography following cold challenge. Methods This was an exploratory, open-label, single-dose Phase 2 trial. Ten female patients (mean age 54.9 years) with mean SSc duration of 11.5 years (all anticentromere antibody positive) and mean RP duration of 14.5 years, were recruited. To be included, patients had to experience ≥5 attacks of RP/week. Patients attended on 6 occasions: screening, baseline (Day 1), and on Days 2, 3, 8, and 15. At baseline, each patient received a single SC injection of 2.5 mg CAM2043 (except the first patient who received 5mg CAM2043). A standard cold challenge test of the hands (15 °C for one minute) was performed pre-dose and at 3-, 6-, 24-, 72-, 168- and 336-hours post-dose, with temperature responses over the subsequent 15 minutes measured by infrared thermography. The primary endpoint was the mean change from baseline to 6 hours post-dose in the area under the curve (AUCtherm) for rewarming (8 fingers). Secondary endpoints included: change from baseline in AUCtherm, maximum temperature after rewarming (MAX) and Raynaud’s Condition Score (RCS). Safety and tolerability were assessed throughout the trial. Results AUCtherm increased 6 hours post-dose, but not statistically significantly: mean increase 192.7 °C×sec (95% CI: -727.1, 1112.6). AUCtherm was significantly greater at 24 hours than at baseline (mean increase 1175.8 °C×sec (95% CI: 127.3, 2224.3)), with a trend towards mean AUCtherm values higher than baseline up to 168 hours post-dose (Day 8) and returning to baseline values at 336 hours (Day 15). A statistically significant increase from baseline was also seen for MAX at 24 hours: mean increase 1.4 °C (95% CI: 0.1, 2.7). At baseline, mean (SD) RCS was 3.7 (1.3) units (10-point scale), and was significantly improved post dosing, including Day 8 (mean reduction 1.6 units (95% CI: -2.68, -0.52)). This positive treatment effect persisted at Day 15 (mean reduction 1.6 units (95% CI: -3.33, 0.19)). Adverse events were reported by all 10 patents: all reported erythema and pain at the injection site. Conclusion Finger skin temperature rose after CAM2043 treatment (significantly at 24 hours post-dose), with significant improvements in RP symptoms (RCS) over the 15-day period following dosing indicating a positive treatment effect. Overall, the safety profile for CAM2043 was consistent with known safety profile for treprostinil, including injection site reactions. The results indicate that CAM2043 could be further investigated in clinical trials of RP. Disclosure A.L. Herrick: Consultancies; Camurus AB. A. Murray: None. G. Dinsdale: None. J. Manning: None. C. Chukwu: None. M. Alvarez Fernandez: Corporate appointments; Camurus AB (employee). J.R. Seibold: Corporate appointments; Medical Lead, Prometheus Biosciences. Consultancies; Camurus AB, Alexion, GlaxoSmithKline, Mitenyi. Shareholder/stock ownership; Prometheus Biosciences. Other; Advisory Committee/Boards: CSL Behring, Prometheus Biosciences, Mitenyi. F. Tiberg: Corporate appointments; President & CEO Camurus AB. Shareholder/stock ownership; Camurus AB. Other; Board Member Camurus AB and Amniotics AB.

Enzymes have come into use for many new applications outside their natural biological environment, taking advantage of their high efficiency and selectivity as biocatalysts. Such new application often requires encapsulation to preserve the structure and activity of the enzyme, but also to regulate and control the activity. Here, we will discuss two types of encapsulation, soft matrices consisting of polar lipid liquid crystals and hard ordered mesoporous silica matrices. For both types of matrices, the challenge is to control the pore size of the matrices and the interaction with the matrix interface. Here, the polar lipid liquid crystals offer larger flexibility than silica, but on the other hand, it is considerably more sensitive to the environment.

TPS4178 Background: Somatostatin receptor ligands (SRLs) are first-line standard of care therapies for gastroenteropancreatic neuroendocrine tumors (GEP-NETs), showing efficacy in tumor/symptom control with an established safety profile. Yet, disease progression may occur despite standard-dose SRL treatment, requiring more aggressive and toxic therapies. Retrospective/non-randomized data suggest higher-dose SRLs may benefit patients with GEP-NETs who do not respond to standard-dose treatment and provide improved disease control. Octreotide depot (CAM2029) is a novel high-exposure, subcutaneous (SC) formulation. Clinical trials showed ̃500% higher CAM2029 bioavailability versus octreotide long-acting release (LAR) (Tiberg et al. 2015), and maintenance/reduction of NET symptoms (Pavel et al. 2019). Prospective, randomized data are needed to confirm the efficacy/safety of novel SRLs with higher bioavailability such as CAM2029, vs standard-dose SRLs including octreotide LAR and lanreotide Autogel (ATG). Methods: SORENTO is a randomized, multi-center, open-label, active-controlled Phase 3 trial, aiming to enroll 302 adults with GEP-NETs. Key eligibility criteria: advanced, well-differentiated NET of GEP/presumed GEP origin; ≥1 measurable SR positive (by nuclear imaging) lesion according to RECIST 1.1; no or < 6 months consecutive treatment with long-acting SRLs. Notably, patients with Grade 3 GEP-NETs (excluded by CLARINET/PROMID trials) are eligible. Patients will be randomized 1:1 to CAM2029 20 mg Q2W, or active comparator (octreotide LAR 30 mg intramuscular or lanreotide ATG 120 mg SC, Q4W). CAM2029 self/carer administration is allowed after ≥3 successful supervised administrations. Randomization stratified by: histological grade, tumor origin, intended comparator. Primary outcome: progression free survival (PFS; time from randomization to date of first documented disease progression [RECIST 1.1] or death), assessed by a Blinded Independent Review Committee. The study is powered to detect a hazard ratio of 0.65. Key secondary outcomes: overall survival; response rate; rescue medication use; patient satisfaction; adverse events. After primary PFS analysis, patient overall survival will be followed for up to 2 years. If CAM2029 displays superiority in the primary analysis, the comparator group may switch to CAM2029 20 mg Q2W. Patients in any treatment group experiencing progressive disease in the randomized part of the study may proceed to an open-label extension with intensified CAM2029 treatment, to investigate effects of higher frequency dosing. First patient randomized in Nov-2021, with readout (following 194 events) expected by 2024 end. This novel head-to-head superiority trial is anticipated to demonstrate the potential benefits of CAM2029 as a first line-therapy in patients with well-differentiated GEP-NETs. Clinical trial information: NCT05050942.

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.

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.

This chapter presents a brief overview of the use of surfactants in inks for ink-jet printing. It aims to provide the reader with a short, self-consistent and pedagogically balanced introduction to this highly technical but, at the same time, largely empirical subject. The adsorption of surfactant at the liquid/vapour interface leads to a reduction in the surface tension of the solution in accordance with the Gibbs law. However, the Gibbs law applies to equilibrium systems. The dynamics of surface tension relaxation can be described in the framework of a diffusion-controlled adsorption model. The model uses the so-called surface-subsurface concept, assuming that the adsorbate is transported by diffusion to a thin interfacial region, called the subsurface, which constantly is in equilibrium with the surface. To describe this equilibrium, an appropriate adsorption isotherm should be used. Different surfactants have different surface tension relaxation dynamics.

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 betw...

AimsTo assess the long‐term safety of subcutaneous buprenorphine (CAM2038) weekly and monthly depots.DesignPhase 3, open‐label, observational, multi‐centre 48‐week trial (ClinicalTrials.gov NCT02672111).SettingTwenty‐six out‐patient sites (United States, United Kingdom, Hungary, Denmark, Sweden, Germany, Australia) between 14 December 2015 and 12 April 2017.ParticipantsTwo hundred and twenty‐eight adults with opioid use disorder; 227 received CAM2038 (37 initiated onto CAM2038 and 190 converted from sublingual buprenorphine).InterventionsCAM2038 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.MeasurementsSafety 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.FindingsThe 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. At the end of the study, the percentage of opioid‐negative urine tests combined with self‐reports was 63.0% (17 of 37) in new‐to‐treatment participants and 82.8% (111 of 190) for participants converted from sublingual buprenorphine. Participants reported high levels of satisfaction with CAM2038.ConclusionsSubcutaneous 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 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.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).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.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.NCT02299089.

IMPORTANCE: Buprenorphine treatment for opioid use disorder may be improved by sustained-release formulations. OBJECTIVE: To determine whether treatment involving novel weekly and monthly subcutaneous (SC) buprenorphine depot formulations is noninferior to a daily sublingual (SL) combination of buprenorphine hydrochloride and naloxone hydrochloride in the treatment of opioid use disorder. DESIGN, SETTING, AND PARTICIPANTS: This outpatient, double-blind, double-dummy randomized clinical trial was conducted at 35 sites in the United States from December 29, 2015, through October 19, 2016. Participants were treatment-seeking adults with moderate-to-severe opioid use disorder. INTERVENTIONS: Randomization to daily SL placebo and weekly (first 12 weeks; phase 1) and monthly (last 12 weeks; phase 2) SC buprenorphine (SC-BPN group) or to daily SL buprenorphine with naloxone (24 weeks) with matched weekly and monthly SC placebo injections (SL-BPN/NX group). MAIN OUTCOMES AND MEASURES: Primary end points tested for noninferiority were response rate (10% margin) and the mean proportion of opioid-negative urine samples for 24 weeks (11% margin). Responder status was defined as having no evidence of illicit opioid use for at least 8 of 10 prespecified points during weeks 9 to 24, with 2 of these at week 12 and during month 6 (weeks 21-24). The mean proportion of samples with no evidence of illicit opioid use (weeks 4-24) evaluated by a cumulative distribution function (CDF) was an a priori secondary outcome with planned superiority testing if the response rate demonstrated noninferiority. RESULTS: A total of 428 participants (263 men [61.4%] and 165 women [38.6%]; mean [SD] age, 38.4 [11.0] years) were randomized to the SL-BPN/NX group (n = 215) or the SC-BPN group (n = 213). The response rates were 31 of 215 (14.4%) for the SL-BPN/NX group and 37 of 213 (17.4%) for the SC-BPN group, a 3.0% difference (95% CI, −4.0% to 9.9%; P

The competitive adsorption of gelatin and sodium dodecyl benzene sulfonate (SDBS) at hydrophobic surfaces was investigated with surface and interfacial tension measurements, ellipsometry, surface p ...

The self-assembly of lipids leads to the formation of a rich variety of nano-structures, not only restricted to lipid bilayers, but also encompassing non-lamellar liquid crystalline structures, such as cubic, hexagonal, and sponge phases. These non-lamellar phases have been increasingly recognized as important for living systems, both in terms of providing compartmentalization and as regulators of biological activity. Consequently, they are of great interest for their potential as delivery systems in pharmaceutical, food and cosmetic applications. The compartmentalizing nature of these phases features mono- or bicontinuous networks of both hydrophilic and hydrophobic domains. To utilize these non-lamellar liquid crystalline structures in biomedical devices for analyses and drug delivery, it is crucial to understand how they interact with and respond to different types of interfaces. Such non-lamellar interfacial layers can be used to entrap functional biomolecules that respond to lipid curvature as well as the confinement. It is also important to understand the structural changes of deposited lipid in relation to the corresponding bulk dispersions. They can be controlled by changing the lipid composition or by introducing components that can alter the curvature or by deposition on nano-structured surface, e.g. vertical nano-wire arrays. Progress in the area of liquid crystalline lipid based nanoparticles opens up new possibilities for the preparation of well-defined surface films with well-defined nano-structures. This review will focus on recent progress in the formation of non-lamellar dispersions and their interfacial properties at the solid/liquid and biologically relevant interfaces.

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.

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 A

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).

Introduction Sublingual buprenorphine is effective for opioid dependence treatment but associated with misuse, abuse, and diversion. The present Phase I/II study evaluated a novel buprenorphine subcutaneous depot formulation for once-weekly dosing (CAM2038 q1w) in patients receiving maintenance treatment for opioid use disorder with daily sublingual buprenorphine. Methods After discontinuation of buprenorphine for 48h, patients received a single CAM2038 q1w dose based on their pre-study daily sublingual maintenance dose. CAM2038 q1w doses of 7.5, 15, 22.5, and 30mg were administered in a sequential dose-escalating design. The following assessments were performed: pharmacokinetics of buprenorphine and norbuprenorphine, pharmacodynamics (evaluated using the Subjective and Clinical Opiate Withdrawal Scales), and time to intake of rescue sublingual buprenorphine medication. Results Single doses of CAM2038 q1w indicated dose-proportional buprenorphine pharmacokinetics (C max and AUC 0–7d ), with time to C max ~20h and an apparent terminal half-life of 3–5days, supporting once-weekly dosing. On average, patients showed a rapid and extended decrease in opiate-withdrawal symptoms from baseline, with zero or very low SOWS and COWS values measured at least up to 7days after dosing of CAM2038 q1w. The median time to first use of rescue buprenorphine was 10days. No dose dependence was seen in the pharmacodynamics, attributable to the selection of CAM2038 q1w doses based on patients' pre-study maintenance doses. CAM2038 q1w was safe and generally well tolerated. Conclusions Pharmacokinetics and pharmacodynamics of a novel buprenorphine subcutaneous depot formulation for once-weekly dosing was evaluated, suggesting utility in maintenance treatment of patients with opioid use disorder.

CAM2038 q1w (once weekly) and q4w (once monthly) are investigational buprenorphine subcutaneous (SC) formulations based on FluidCrystal® injection depot technology. These two drug products are being developed for opioid dependence treatment, with a target for once-weekly and once-monthly SC dosing. The rationale for developing two products with different dosing frequencies is that treatment strategies/routines, and hence different treatment preferences, can vary between patients, different stages of opioid maintenance treatment, and countries. This study evaluated the pharmacokinetics and safety of buprenorphine and norbuprenorphine following administration of CAM2038 q1w or q4w versus active controls. Healthy volunteers were randomized to five treatment groups. All received a single intravenous dose of buprenorphine 600 µg, followed post-washout by a single dose of CAM2038 q4w 96 mg, a single dose of CAM2038 q4w 192 mg, or sublingual buprenorphine 8, 16, or 24 mg daily for 7 days, followed post-washout by a single dose of CAM2038 q4w 64 or 128 mg or four repeated weekly doses of CAM2038 q1w 16 mg. All subjects received daily naltrexone. Eighty-seven subjects were randomized. Median buprenorphine t max after CAM2038 q4w was 4–10 h (24 h for CAM2038 q1w); mean terminal half-life was 19–25 days (5 days for CAM2038 q1w). CAM2038 q4w showed dose-proportional buprenorphine release, with similar exposure to repeat-dose CAM2038 q1w at comparable monthly dose level. Both CAM2038 formulations showed complete absolute bioavailability of buprenorphine and 5.7- to 7.7-fold greater buprenorphine bioavailability versus sublingual buprenorphine. CAM2038 q1w and q4w were well tolerated; subjects’ acceptance was higher for CAM2038 than for sublingual buprenorphine 1 h post-dose. The pharmacokinetic profiles of CAM2038 q1w and q4w versus sublingual buprenorphine support expected treatment efficacy with once-weekly and once-monthly dosing, respectively. CAM2038 formulations were safe and showed good local tolerability. Trial registration: ISRCTN24987553. Funding: Camurus AB.

Investigation of nonlamellar nanoparticles formed by dispersion of self-assembled lipid liquid crystalline phases is stimulated by their many potential applications in science and technology; resulting from their unique solubilizing, encapsulating, and space-dividing nature. Understanding the interfacial behavior of lipid liquid crystalline nanoparticles (LCNPs) at surfaces can facilitate the exploitation of such systems for a number of potentially interesting uses, including preparation of functional surface coatings and uses as carriers of biologically active substances. We have studied the adsorption of LCNP, based on phosphatidylcholine/glycerol dioleate and Polysorbate 80 as stabilizers, at different model surfaces by use of in situ ellipsometry. The technique allows time-resolved monitoring of the layer thickness and the amount adsorbed, thereby providing insights into the restructuring of the lipid nanoparticle upon adsorption. The effects of solvent condition, electrolyte concentration, particle size, and surface chemistry on adsorbed layer properties were investigated. Furthermore, the internal structures of the particles were investigated by cryo-transmission electron microscopy and small angle X-ray diffraction on the corresponding liquid crystalline phases in excess water. LCNPs are shown to form well-defined layers at the solid-liquid interface with a structure and coverage that are determined by the interplay between the self-assembly properties of the lipids and lipid surface interactions, respectively. At the hydrophobic surface, hydrophobic interaction results in a structural transition from the original LCNP morphology to a monolayer structure at the interface. In contrast, at cationic and hydrophilic surfaces, relaxation is a relatively slow process, resulting in much thicker adsorbed layers, with thickness and adsorption behavior that to a greater extent reflect the original bulk LCNP properties.

Neutron reflectometry was used to study the co-adsorption of calcium phosphate nanoclusters (CPN) and beta-casein at hydrophobized and hydrophilic silica-water interfaces. The structural characteristics of the adsorbed layer were determined from neutron reflectivity curves analysed with multi-layer optical models. We used a highly specific proteolytic enzyme, endoproteinase Asp-N in conjunction with a single neutron contrast to verify the model of the protein layer structure. The results showed that the calcium phosphate nanoclusters profoundly affected the rate of adsorption and structure of the interface compared to the adsorption of beta-casein alone and for the hydrophobic interface the effects depended on the point at which the nanoclusters were added. It is proposed that the nanoclusters become surface active because whole beta-casein molecules can replace one or more of the hydrophilic peptides in the shell of the nanoclusters. (C) 2010 Elsevier Ltd. All rights reserved. (Less)

The kinetics of structure change when dispersions of two different types of lipid-based liquid-crystalline phases, one lamellar and one reversed, are mixed has been investigated using synchrotron small-angle X-ray diffraction and ellipsometry. The systems studied were (i) cubic-phase nanoparticles (CPNPs) based on glycerol monooleate (GMO) stabilized with a nonionic block copolymer, Pluronic F-127; (ii) CPNPs based on phytantriol (PtOH) stabilized with D-alpha-Tocopheryl polyethylene glycol 1000 succinate (Vitamin E TPGS); and (iii) hexagonal-phase nanoparticles (HPNPs) based on a lipid mixture of diglycerol monooleate/glycerol dioleate, stabilized by Pluronic F-127. Time-resolved small-angle X-ray diffraction was used to track structural changes within nonlamellar nanoparticles when they interact with uni- and multilamellar vesicles of dioleoylphosphatidylcholine and dipalmitoylphatidylcholine. The results are very dependent on the type of nanoparticles under investigation. For GMO-based CPNPs, a strong interaction is observed on mixing with vesicular dispersions that leads to large changes in unit size dimensions as well as a later transition from cubic to lamellar structure. These results are in good agreement with previous studies on the interaction of GMO-based CPNPs with planar bilayers using neutron reflectivity, where the diffraction peak shifted with time upon mixing. The structural changes are much less prominent for the PtOH-based CPNPs and the HPNPs upon mixing with phospholipid vesicles. These results are correlated with those from measurement studying interactions between the liquid-crystalline nanoparticles and supported phospholipid bilayers by ellipsometry. Also, here the GMO-based CPNPs show more pronounced and rapid adsorption and interaction with the supported bilayer surface than do the other types of nonlamellar nanoparticles. The interaction also depends on the bilayer properties, where significantly slower lipid mixing is observed for a bilayer in the gel state compared to a bilayer in the liquid-crystalline phase. This study is not only relevant for drug-delivery applications but also shows the potential of synchrotron small-angle X-ray diffraction in studying time-dependent structural changes as a consequence of the interaction between different lipid self-assembled aggregates in complex systems.

Pharmacy-grade exogenous lung surfactant preparations of bovine and porcine origin, dispersed in physiological electrolyte solution have been studied. The organization and dynamics at the air/water interface at physiological temperature was analysed by neutron reflection. The results show that a well-defined surface phase is formed, consisting of a multilayer structure of lipid/protein bilayers alternating with aqueous layers, with a repetition period of about 70 A and correlation depths of 3 to >25 bilayers, depending on electrolyte composition and time. The experimental surfactant concentration of 0.15% (w/w) is far below that used in therapeutic application of exogenous surfactants and it is therefore likely that similar multilayer structures are also formed at the alveolar surface in the clinical situation during surfactant substitution therapy. Lung surfactant preparations in dry form swell in aqueous solution towards a limit of about 60% (w/w) of water, forming a lamellar liquid-crystalline phase above about 34 degrees C, which disperses into lamellar bodies at higher water concentrations. The lamellar spacings in the surface multilayers at the air/water interface are smaller than those in the saturated limit even though they are in contact with much greater water concentrations. The surface multilayers are laterally disordered in a way that is consistent with fragments of Lalpha-phase lamellae. The near surface layers of the multilayer structure have a significant protein content (only SP-B and SP-C are present in the preparations). The results demonstrate that a multilayer structure can be formed in exogenous surfactant even at very low concentrations and indicate that multilayers need to be incorporated into present interpretations of in vitro studies of similar lung surfactant preparations, which are largely based on monolayer models.

The adsorption behavior of self-assembled lipid liquid crystalline nanoparticles at different model surfaces was investigated in situ by use of ellipsometry. The technique allows time-resolved monitoring of the adsorbed amount and layer thickness under transient and steady-state conditions. The system under study was cubic-phase nanoparticle (CPNP) dispersions of glycerol monooleate stabilized by a nonionic block copolymer, Pluronic F-127. Depending on the surface properties and presence of electrolytes, different adsorption scenarios were discerned: At hydrophilic silica thick surface layers of CPNPs are generated by particle adsorption from dispersions containing added electrolyte, but no adsorption is observed in pure water. Adsorption at the hydrophobic surface involves extensive structural relaxation and formation, which is not electrolyte sensitive, of a classic monolayer structure. The different observations are rationalized in terms of differences in interactions among the CPNP aggregates, their unimer constituents, and the surface and show a strong influence of interfacial interactions on structure formation. Surface self-assembly structures with properties similar to those of the corresponding bulk aggregates appear exclusively in the weak interaction limit. This observation is in agreement with observations for surfactant self-assembly systems, and our findings indicate that this behavior is applicable also to complex self-assembly structures such as the CPNP structures discussed herein.

Liquid crystalline nanoparticles (LCNP) formed through lipid self-assembly have a range of attractive properties as in vivo drug delivery carriers. In particular they offer: a wide solubilization spectrum, and consequently high drug payloads; effective encapsulation; stabilization and protection of sensitive drug substances. Here we present basic physicochemical features of non-lamellar LCNP systems with a focus on intravenous drug applications. This is exemplified by the formulation properties and in vivo behavior using the drug substance propofol; a well-known anesthetic agent currently used in clinical practice in the form of a stable emulsion. In order to appraise the drug delivery features of the LCNP system the current study was carried out with a marketed propofol emulsion product as reference. In this comparison the propofol-LCNP formulation shows several useful features including: higher drug-loading capacity, lower fat-load, excellent stability, modified pharmacokinetics, and an indication of increased effect duration.

The accumulated evidence for the existence of periodic minimal surface (PMS) bilayer structure of the bicontinuous cubic phases in lipidwater systems is summarized. There are three fundamental PMS: the G, D, and P types. These three and no others have been observed in lipid-water systems. Due to the so-called Bonnet relation, the PMS structures are isometric conjugates to one another at coexistence, which determines the cubic axis ratio and water content at equilibrium. A number of lipid systems exhibiting coexisting cubic phases have been examined in relation to fulfilling the Bonnet relation. In all cases with known unit cell dimensions, the phases are Bonnet-related. This is regarded as strong evidence for their PMS structure. The phase transitions in relation to swelling and water content also fulfill the Bonnet relations. Aside from bulk phases with PMS structure, it has also been shown possible to produce nanoparticles with internal PMS structure. New developments enable the manufacturing of such particles with uniform size and internal structure, of interest in practical applications such as in vivo delivery of drugs. (c) 2004 Elsevier Ltd. All rights reserved. (Less)

The effects of enzyme structure and activity on the degradation of model cellulose substrates were investigated by ellipsometry for the cellulase Humicola insolens GH45. The inactive variant D10N was found to adsorb at the cellulose surface but also to be incorporated into the cellulose films to an extent that depended on pH. For the native protein, the initial adsorption monitored for the inactive variant D10N was followed by enzyme-mediated degradation of the cellulose films. Again, a dependence on pH was found, such that higher pH resulted in slower enzymatic degradation. Removing the carbohydrate-binding module eliminated this pH dependence but also resulted in a decreased adsorption to the cellulose surface, and in a decreased net catalytic effect.

Synthesis of 1-glyceryl monooleyl ether (GME) has been accomplished yielding material of high purity (99.6%). The aqueous phase behavior of synthesized lipid has been investigated by using polarized microscopy and small angle X-ray diffraction. As a result, a partial temperature-composition phase diagram has been constructed. GME forms a reversed micellar solution and reversed hexagonal liquid crystalline phase at low and high hydration, respectively. The hexagonal phase coexists with excess water and is stable up to about 63 degreesC. These findings make GME an interesting alternative to glycerol monoesters in various fields of applications. (C) 2004 Elsevier B.V. All rights reserved.

The present article provides current opinion on studies of the interfacial dynamics, adsorption, and structure of surfactant layers. The physical principles and applications of physicochemical methods such as tensiometry, ellipsometry, photon correlation spectroscopy, and neutron reflectivity techniques, as well as relevant theoretical aspects related to the adsorption and desorption kinetics, interfacial structure development, wetting enhancement, and the effect of adsorbed surfactant films of the interfacial dynamics, are covered in detail. In order to make the text as self-contained as possible, essential mathematical derivations are given demonstrating how raw data, such as ellipsometric angles or neutron reflectivity, are transformed into sought layer characteristics, such as thickness or density.

Methods and compositions for producing lipid-based cubic phase nanoparticles were first discovered in the 1990s. Since then a number of studies have been presented, but little is known about how to control key properties such as particle size, morphology, and stability of cubic phase dispersions. In the present work we give examples of how these properties can be tuned by composition and processing conditions. Importantly we show that stable particle dispersions with consistent size and structure can be produced by a simple processing scheme comprising a homogenization and heat treatment step.

We have investigated the formation of supported bilayers by coadsorption of dipalmitoyl phosphatidylcholine (DPPC) with the nonionic surfactant beta-D-dodecyl maltoside. The adsorption of mixed phospholipid-surfactant micelles on hydrophilic silica surfaces at 25 degrees C was followed as a function of bulk concentration by neutron reflection. Using chain-deuterated d(25)-beta-D-dodecyl maltoside and d(62)-DPPC, we demonstrate that it is possible to determine the composition of the bilayers at each stage of a sequential dilution process, which enriches the adsorbed layer in phospholipid and leads to complete elimination of the surfactant. The final supported bilayers have thicknesses of 51 +/- 3 A and are stable to heating to 37 degrees C once all surfactant has been removed, and the structures agree well with other published data on DPPC supported bilayers. The coadsorption of cholesterol in a DPPC-surfactant mixture was also achieved, and the location and volume fraction of cholesterol in the DPPC bilayer was determined. Cholesterol is located in a 18 +/- 1 A thick layer below the lipid headgroup region and leads to an increased bilayer thickness of 58 +/- 2 A at 26 mol % of cholesterol.

We have investigated the formation of supported model membranes via the adsorption of phospholipid-surfactant mixtures at the Si water interface by specular neutron reflection. The adsorption of mixed micelles of the nonionic surfactant beta-D-dodecyl maltoside and DOPC or POPC was determined as a function of bulk concentration, and using d(25)-beta-D-dodecyl maltoside, the composition of DOPC and POPC bilayers was determined. Bilayer thicknesses of 39 +/- 3 (A) dot over for DOPC and 41 +/- 3 A for POPC agree well with data from bulk lamellar phases for both lipids, and the average area per lipid molecule can be varied from 62 to 115 (A) dot over (2) by varying the bulk concentrations used. The amount of surfactant in the bilayer is very sensitive to the bulk volume-to-surface area ratio, but it can be fully eliminated by ensuring a sufficiently large dilution/rinsing volume of the solution. (C) 2004 Elsevier B.V. All rights reserved.

Neutron reflectometry was used to investigate effects of calcium ions on the interfacial behavior of beta-casein at the silicon oxide-aqueous solution interface. The structural characteristics of the adsorbed layer were determined from reflectivity curves fitted to three- and two-layer optical models. The results showed that the presence of divalent calcium ions decreased the specific electrostatic adsorption affinity of the protein to silica compared with the calcium-free buffer system studied in an earlier work. In addition, it speeded up the adsorption suggesting that the slow kinetics seen in the calcium-free system are related to conformational adjustments of the beta-casein structure driven by the maximization of the number of positive charges on the polypeptide interacting with negative surface charges. In the calcium-free system, a dense inner layer resulted from this process, with cationic segments firmly bound to the negative surface, whereas in the presence of calcium, a less dense inner layer was formed. The difference in binding is also mirrored by the effects on the interfacial layer of a specific proteolytic enzyme, i.e., endoproteinase Asp-N. In the calcium-free case, an inner dense layer remained at the surface after the proteolytic cleavage of the polypeptide, whereas virtually nothing was left after enzymatic action in the presence of calcium ions.

The paper reports results of experimental studies on the dynamic behavior of surfactant solution drops on substrates with differing hydrophobicity. Contact angle oscillations observed immediately after the drop deposition are studied, and a mechanistic interpretation of this phenomenon is put forward. The major emphasis is put on the physicochemical aspects of surfactant action, including the dynamic wetting enhancement and the effect of surface tension relaxation on the frequency of drop oscillation, which are characteristic of surfactant solutions. Appropriate scaling relations describing the drop dynamics are derived.

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.

The formation and structure of multilayer films containing a cationic polyelectrolyte and anionic silica nanoparticles were studied by means of ellipsometry and atomic force microscopy. Three types of silica particles of different sizes were examined. The density and thickness of the films as well as the adsorption kinetics appear to be strongly dependent on the choice of particle; smaller particles favor the formation of smooth and dense films with a higher content of the inorganic component.

In this work the effect of ionic strength on the adsorption behavior of cationic polyelectrolyte (acrylamide–acrylamidopropyltrimethylammonium chloride) and negatively charged silica particles has been studied by means of ellipsometry. The adsorption of the polyelectrolyte was observed to increase with increasing salt concentration, a behavior typical for polyelectrolytes with a screening-reduced solvency and a nonelectrostatic affinity for the surface. A similar dependence on the ionic strength was observed when studying the electrolyte effect on the nanoparticle adsorption to the preadsorbed polyelectrolyte film, suggesting that the polyelectrolyte surface conformations largely govern the binding capacity of the particles to the surface.

The buildup and structure of multilayer films containing cationic polyelectrolyte and silica nanoparticles have been studied by means of ellipsometry, atomic force microscopy, and X-ray photoelectron spectroscopy. Emphasis was placed on the effect of ionic strength on the adsorption behavior and structure formation. Consecutive exposure of a silica substrate to low ionic strength solutions containing polyelectrolyte and nanoparticles resulted in the formation of stable adsorbed films with a reproducible stratified multilayer structure. The films formed in high ionic strength solutions were initially much thicker but also clearly less stable. A significant desorption was observed to take place in conjunction with the second exposure to silica nanoparticles. The effect of electrolyte concentration is discussed in terms of a salt-induced glass−liquid transition, above which the relaxation rate in the adsorbed composite film increases and thereby hinders the formation of multilayer structures.

Buprenorphine is an efficacious, widely used treatment for opioid use disorder (OUD). Daily oral transmucosal formulations can be associated with misuse, diversion, and nonadherence; these limitations may be obviated by a sustained release formulation.To evaluate the ability of a novel, weekly, subcutaneous buprenorphine depot formulation, CAM2038, to block euphorigenic opioid effects and suppress opioid withdrawal in non-treatment-seeking individuals with OUD.This multisite, double-blind, randomized within-patient study was conducted at 3 controlled inpatient research facilities. It involved 47 adults with DSM-V moderate-to-severe OUD. The study was conducted from October 12, 2015 (first patient enrolled), to April 21, 2016 (last patient visit).A total of five 3-day test sessions evaluated the response to hydromorphone (0, 6, and 18 mg intramuscular in random order; 1 dose/session/day). After the first 3-day session (ie, qualification phase), participants were randomized to either CAM2038 weekly at 24 mg (n = 22) or 32 mg (n = 25); the assigned CAM2038 dose was given twice, 1 week apart (day 0 and 7). Four sets of sessions were conducted after randomization (days 1-3, 4-6, 8-10, and 11-13).The primary end point was maximum rating on the visual analog scale for drug liking. Secondary end points included other visual analog scale (eg, high and desire to use), opioid withdrawal scales, and physiological and pharmacokinetic outcomes.A total of 46 of 47 randomized participants (mean [SD] age, 35.5 [9] years; 76% male [n = 35]) completed the study. Both weekly CAM2038 doses produced immediate and sustained blockade of hydromorphone effects (liking maximum effect, CAM2038, 24 mg: effect size, 0.813; P .001, and CAM2038, 32 mg: effect size, 0.753; P .001) and suppression of withdrawal (Clinical Opiate Withdrawal Scale, CAM2038, 24 mg: effect size, 0.617; P .001, and CAM2038, 32 mg: effect size, 0.751; P .001). CAM2038 produces a rapid initial rise of buprenorphine in plasma with maximum concentration around 24 hours, with an apparent half-life of 4 to 5 days and approximately 50% accumulation of trough concentration from first to second dose (trough concentration = 0.822 and 1.23 ng/mL for weeks 1 and 2, respectively, with 24 mg; trough concentration = 0.993 and 1.47 ng/mL for weeks 1 and 2, respectively, with 32 mg).CAM2038 weekly, 24 and 32 mg, was safely tolerated and produced immediate and sustained opioid blockade and withdrawal suppression. The results support the use of this depot formulation for treatment initiation and stabilization of patients with OUD, with the further benefit of obviating the risk for misuse and diversion of daily buprenorphine while retaining its therapeutic benefits.Clinicaltrials.gov Identifier: NCT02611752.

Lipid nanoparticles of reversed internal phase structures, such as cubic micellar (I2) structure show good drug loading ability of peptides and proteins as well as some small molecules. Due to their controllable small size and inner morphology, such nanoparticles are suitable for drug delivery using several different administration routes, including intravenous, intramuscular, and subcutaneous injection. A very interesting system in this regard, is the two component soy phosphatidylcholine (SPC)/glycerol dioleate (GDO) system, which depending on the ratio of the lipid components form a range of reversed liquid crystalline phases. For a 50/50 (w/w) ratio in excess water, these lipids have been shown to form a reversed cubic micellar (I2) phase of the Fd3m structure. Here, we demonstrate that this SPC/GDO phase, in the presence of small quantities (5-10 wt %) of Polysorbate 80 (P80), can be dispersed into nanoparticles, still with well-defined Fd3m structure. The resulting nanoparticle dispersion has a narrow size distribution and exhibit good long-term stability. In pharmaceutical applications, biodegradation pathways of the drug delivery vehicles and their components are important considerations. In the second part of the study we show how the structure of the particles evolves during exposure to a triacylglycerol lipase (TGL) under physiological-like temperature and pH. TGL catalyzes the lipolytic degradation of acylglycerides, such as GDO, to monoglycerides, glycerol, and free fatty acids. During the degradation, the interior phase of the particles is shown to undergo continuous phase transitions from the reversed I2 structure to structures of less negative curvature (2D hexagonal, bicontinuous cubic, and sponge), ultimately resulting in the formation of multilamellar vesicles.

Surfactant transport through the three-phase contact line is studied in relation to the wetting-enhancing effect of surfactants. A specially designed experimental setup is used to simultaneously monitor interfacial adsorption and wetting tension during forced immersion of a hydrophobic or hydrophilic plate into aqueous surfactant solutions. The adsorption at the liquid/solid interface has been measured by ellipsometry, the wetting tension has been determined according to the Wilhelmy plate method, and the adsorption to the liquid/vapor interface has been evaluated from surface tension measurements. The relative importance of different adsorption modes could thereby be grasped. For hydrophobic substrates, the dynamic wetting behavior is strongly affected by surfactant carryover through the advancing three-phase contact line, which appears to be the dominant mode of surfactant transport to the solid/liquid interface. Conversely, for hydrophilic substrates, three-phase contact line carryover of surfactant do...

Alkyl ketene dimers (AKD) only partially wet cellulose and silica surfaces. Further spreading of AKD molecules is shown to occur by surface diffusion in the form of an autophobic monolayer precur ...

This paper features the interfacial behavior of nonionic surfactants and surfactant−decane microemulsions at the silica−water interface from micellar solutions and water-rich tricomponent CnEm−decane−water microemulsions. The adsorption of a nonionic surfactant (pentaethyleneglycol n-dodecyl ether, C12E5) and its decane microemulsions to silica and borosilicate glass was studied by ellipsometry and direct force measurements using a bimorph surface force apparatus. The ellipsometric measurements of the adsorbed layer properties provided evidence of an initial lateral swelling of adsorbed bilayer segments with increasing bulk oil fraction. At a weight fraction of about 0.12 w/w decane-to-surfactant + decane, the surface appeared to be fully covered by a continuous bilayer with a thickness of 42 A, a refractive index of 1.448, and an mean area per surfactant of about 49 A2. Further increase of the oil content results in the swelling of the bilayer in the direction normal to the surface plane. Force measureme...