Mechanistic study of scale inhibitors retention in carbonate formations for application in squeeze treatment

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Intradermal Administration of Fractional Doses of Inactivated Poliovirus Vaccine: A Dose-Sparing Option for Polio Immunization.

A fractional dose of inactivated poliovirus vaccine (fIPV) administered by the intradermal route delivers one fifth of the full vaccine dose administered by the intramuscular route and offers a potential dose-sparing strategy to stretch the limited global IPV supply while further improving population immunity. Multiple studies have assessed immunogenicity of intradermal fIPV compared with the full intramuscular dose and demonstrated encouraging results. Novel intradermal devices, including intradermal adapters and disposable-syringe jet injectors, have also been developed and evaluated as alternatives to traditional Bacillus Calmette-Guérin needles and syringes for the administration of fIPV. Initial experience in India, Pakistan, and Sri Lanka suggests that it is operationally feasible to implement fIPV vaccination on a large scale. Given the available scientific data and operational feasibility shown in early-adopter countries, countries are encouraged to consider introducing a fIPV strategy into their routine immunization and supplementary immunization activities

Evaluating Islatravir Administered Via Microneedle Array Patch for Long-Acting HIV Pre-exposure Prophylaxis Using Physiologically Based Pharmacokinetic Modelling

Background and objectivesTechnologies for long-acting administration of antiretrovirals (ARVs) for the prevention and treatment of HIV are at the forefront of research initiatives aiming to tackle issues surrounding drug adherence with the current standard of once-daily oral administration. Islatravir (ISL) is an emerging ARV that shows promising characteristics for long-acting prevention and treatment both orally as well as through alternative routes of administration. Microneedle array patches (MAPs) are a pain-free and discreet transdermal delivery technology that offer extended-release administration of nanoparticulate drugs. This study aimed to utilise physiologically based pharmacokinetic (PBPK) modelling to predict the pharmacokinetics resulting from ISL administered via MAP and to identify key MAP characteristics required to sustain effective concentrations over extended dosing intervals.MethodsA PBPK model describing the conversion of ISL to ISL-triphosphate (ISL-TP) and its whole-body disposition was developed and verified against observed clinical data for orally administered ISL in healthy adults. An intradermal PBPK model was integrated with the ISL PBPK model to predict the dose and nanoparticle release rate required for MAP administration strategies capable of achieving a minimum ISL-TP target concentration of 0.05 pmol/106 PBMCs over extended dosing intervals. MAP design was limited to a maximum therapeutic area of 20 cm2 with a dose loading of 4.09 mg/cm2 and a minimum duration of 3 months. Due to the lack of available clinical data, a range of nanoparticle release rates and MAP bioavailability scenarios were simulated to provide an overview of potential clinical outcomes.ResultsThe ISL PBPK model was successfully verified, with predicted vs observed ratios falling within 0.5-2-fold. ISL MAP doses ranging from 15 to 80 mg were predicted to sustain ISL-TP concentrations above the minimum target concentration at 3, 6 and 12 months after administration. Nanoparticle release rate and MAP bioavailability were found to have a major impact on whether dosing strategies achieved the criteria. Minimum doses of 15 mg and 60 mg with a nanoparticle release rate of 0.0005 h-1 and bioavailability ranging from 25 to 100% were predicted to achieve effective ISL-TP concentrations up to 3 and 6 months, respectively. Doses of 15 mg and 30 mg with a nanoparticle release rate of 0.0005 h-1 were also able to attain the target concentration up to 6 months after MAP administration, albeit with a minimum bioavailability of 75% and 50%, respectively. Furthermore, when simulating a bioavailability of 100%, an 80 mg ISL MAP was predicted to sustain ISL-TP concentrations above the minimum target concentration up to 12 months after administration.ConclusionsThe ISL PBPK model successfully predicted ISL and ISL-TP pharmacokinetics across a range of orally administered regimens. The integrated intradermal PBPK model outlined optimal MAP dose and nanoparticle release rates for effective ISL-TP concentrations up to 12 months, providing justification for further investigation of ISL as a candidate for MAP administration

Microarray patch for HIV prevention and as a multipurpose prevention technology to prevent HIV and unplanned pregnancy: an assessment of potential acceptability, usability, and programmatic fit in Kenya

BackgroundMicroarray patches (MAPs), a novel drug delivery system, are being developed for HIV pre-exposure prophylaxis (PrEP) delivery and as a multipurpose prevention technology (MPT) to protect from both HIV and unintended pregnancy. Prevention technologies must meet the needs of target audiences, be acceptable, easy to use, and fit health system requirements.MethodologyWe explored perceptions about MAP technology and assessed usability, hypothetical acceptability, and potential programmatic fit of MAP prototypes using focus group discussions (FGD), usability exercises, and key informant interviews (KII) among key populations in Kiambu County, Kenya. Adolescent girls and young women (AGYW), female sex workers (FSW), and men who have sex with men (MSM) assessed the usability and acceptability of a MAP prototype. Male partners of AGYW/FSW assessed MAP acceptability as partners of likely users. We analyzed data using NVivo, applying an inductive approach. Health service providers and policymakers assessed programmatic fit. Usability exercise participants applied a no-drug, no-microneedle MAP prototype and assessed MAP features.ResultsWe implemented 10 FGD (4 AGYW; 2 FSW; 2 MSM; 2 male partners); 47 mock use exercises (19 AGYW; 9 FSW; 8 MSM; 11 HSP); and 6 policymaker KII. Participants reported high interest in MAPs due to discreet and easy use, long-term protection, and potential for self-administration. MAP size and duration of protection were key characteristics influencing acceptability. Most AGYW preferred the MPT MAP over an HIV PrEP-only MAP. FSW saw value in both MAP indications and voiced need for MPTs that protect from other infections. Preferred duration of protection was 1–3 months. Some participants would accept a larger MAP if it provided longer protection. Participants suggested revisions to the feedback indicator to improve confidence. Policymakers described the MPT MAP as “killing two birds with one stone,” in addressing AGYW needs for both HIV protection and contraception. An MPT MAP is aligned with Kenya's policy of integrating health care programs.ConclusionsMAPs for HIV PrEP and as an MPT both were acceptable across participant groups. Some groups valued an MPT MAP over an HIV PrEP MAP. Prototype refinements will improve usability and confidence

A new practical method to evaluate the Joule-Thomson coefficient for natural gases

© 2017, The Author(s). The Joule–Thomson (JT) phenomenon, the study of fluid temperature changes for a given pressure change at constant enthalpy, has great technological and scientific importance for designing, maintenance and prediction of hydrocarbon production. The phenomenon serves vital role in many facets of hydrocarbon production, especially associated with reservoir management such as interpretation of temperature logs of production and injection well, identification of water and gas entry locations in multilayer production scenarios, modelling of thermal response of hydrocarbon reservoirs and prediction of wellbore flowing temperature profile. The purpose of this study is to develop a new method for the evaluation of JT coefficient, as an essential parameter required to account the Joule–Thomson effects while predicting the flowing temperature profile for gas production wells. To do this, a new correction factor, CNM, has been developed through numerical analysis and proposed a practical method to predict CNM which can simplify the prediction of flowing temperature for gas production wells while accounting the Joule–Thomson effect. The developed correlation and methodology were validated through an exhaustive survey which has been conducted with 20 different gas mixture samples. For each sample, the model has been run for a wide range of temperature and pressure conditions, and the model was rigorously verified by comparison of the results estimated throughout the study with the results obtained from HYSYS and Peng–Robinson equation of state. It is observed that model is very simple and robust yet can accurately predict the Joule–Thomson effect

Inactivation of anandamide signaling : A continuing Debate

Copyright 2011 Elsevier B.V., All rights reserved.Peer reviewedPublisher PD

Design, Formulation, and Evaluation of Novel Dissolving Microarray Patches Containing Rilpivirine for Intravaginal Delivery

Antiretroviral (ARV) drugs have, for many years, been studied and administered in the prevention and treatment of human immunodeficiency virus (HIV). Intramuscular (IM) injection of long acting (LA) ARVs are in clinical development, but injectable formulations require regular access to healthcare facilities and disposal facilities for sharps. The development of a discrete, self‐administered, and self‐disabling vehicle to deliver ARVs could obviate these issues. This study describes the formulation, mechanical characterization, and in vivo evaluation of dissolving microarray patches (MAPs) containing a LA nanosuspension of the ARV, rilpivirine (RPV, RPV LA), for vaginal delivery. This is the first study to apply MAPs into vaginal tissue. The RPV LA MAPs penetrate ex vivo skin and a synthetic vaginal skin model and withstand the effects of potential dragging motion across synthetic vaginal epithelium. In in vivo studies, the mean plasma concentration of RPV in rats at the 56 day endpoint (116.5 ng mL−1) is comparable to that achieved in the IM control cohort (118.9 ng mL−1). RPV is detected systemically, in lymph and vaginal tissue, indicating the potential to deliver RPV LA to primary sites of viral challenge and replication. This innovative research has future potential for patients and healthcare workers, particularly in low‐resource settings