scholarly journals A new combination bictegravir+tenofovir alafenamide nanoformulation with prolonged sustained-drug-release potency for HIV-1 PrEP: A concept evaluation study.

2021 ◽  
Author(s):  
Subhra Mandal ◽  
Pavan Kumar Prathipati ◽  
Shawnalyn W Sunagawa ◽  
Christopher J. Destache
Keyword(s):  
Sustained Release ◽  
Evaluation Study ◽  
New Combination ◽  
Sustained Drug Release ◽  
Drug Concentrations ◽  
Concept Evaluation ◽  
Tenofovir Alafenamide ◽  
Hiv 1

The antiretroviral treatment (ART) approach is the best-prescribed approach to date for pre-exposure prophylaxis (PrEP) for high-risk individuals. However, the daily combination ARVs (cARVs) regimen has become cumbersome for healthy individuals leading to non-adherence. Recent surveys showed high acceptance of parenteral sustained-release ART enhancing PrEP adherence. Our approach is to design a parenteral nanoparticle (NP)-based cARV sustained-release (cARV-SR) system as long-acting HIV PrEP. In this work, we reported a new combination of two potent ARV, (tenofovir alafenamide fumarate (TAF) and bictegravir (BIC)) loaded nanoformulation intended as cARV-SR for PrEP. The BIC+TAF NPs were fabricated by standardized in-house methodology. In-vitro intracellular kinetics, cytotoxicity, and HIV-1 protection studies demonstrated BIC+TAF encapsulation prolonged drug retention, reduced drug-associated cytotoxicity, and enhanced HIV protection. In human PBMCs, nanoformulated BIC+TAF demonstrated significant (p < 0.05) improvement in the drug’s selectivity index by 472 times compared to the BIC+TAF in solution. In-vivo pharmacokinetic (PK) study of BIC, TAF and respective drug metabolite in female BALB/c mice after single subcutaneous BIC+TAF NPs demonstrated plasma drug concentrations of BIC and tenofovir (TFV) above intracellular IC50 level during the entire 30-day study period, and prolonged persistence of both active drugs in the HIV target organs including vagina, colon, spleen, and lymph nodes. This report demonstrated encapsulation of BIC+TAF in a nanoformulation improved its therapeutic selectivity and in-vivo pharmacokinetics of free drugs. Based on these preliminary studies, we hypothesize cARV-SR has potential as an innovative once monthly delivery for PrEP.

scholarly journals Antiviral Activity of Tenofovir Alafenamide against HIV-1 with Thymidine Analog-Associated Mutations and M184V

2020 ◽  
Vol 64 (4) ◽  
Author(s):  
Nicolas Margot ◽  
Renee Ram ◽  
Michael Abram ◽  
Richard Haubrich ◽  
Christian Callebaut
Keyword(s):  
Physiological Concentration ◽  
Viral Breakthrough ◽  
Phenotypic Resistance ◽  
Thymidine Analog ◽  
Drug Concentrations ◽  
Tenofovir Alafenamide ◽  
Hiv 1 ◽  
M184v Mutation

ABSTRACT Tenofovir alafenamide (TAF) and tenofovir disoproxil fumarate (TDF) are prodrugs of the HIV-1 nucleotide reverse transcriptase inhibitor tenofovir (TFV). In vivo, TAF achieves >4-fold-higher intracellular levels of TFV diphosphate (TFV-DP) compared to TDF. Since thymidine analog-associated mutations (TAMs) in HIV-1 confer reduced TFV susceptibility, patients with TAM-containing HIV-1 may benefit from higher TFV-DP levels delivered by TAF. Moreover, the presence of the M184V mutation increases TFV susceptibility during TDF- or TAF-based therapy. The susceptibilities to antiviral drugs of site-directed mutants (SDMs) and patient-derived mutants containing combinations of TAMs (M41L, D67N, K70R, L210W, T215Y, and K219Q) with or without the M184V mutation (TAMs±M184V) were evaluated using either 5-day multicycle (MC; n = 110) or 2-day single-cycle (SC; n = 96) HIV assays. The presence of M184V in TAM-containing HIV-1 SDMs (n = 48) significantly increased TAF sensitivity compared to SDMs without M184V (n = 48). The comparison of TAF and TDF resistance profiles was further assessed in viral breakthrough (VB) experiments mimicking clinically relevant drug concentrations. A total of 68 mutants were assayed at physiological concentration in VB experiments, with 15/68 mutants breaking through with TDF (TFV, the in vitro equivalent of TDF, was used in these experiments), and only 3 of 68 mutants breaking through under TAF treatment. Overall, in the VB assay mimicking the 4-fold-higher intracellular levels of TFV-DP observed clinically with TAF versus TDF, TAF inhibited viral breakthrough of most TAM-containing HIV-1, whereas TDF did not. These results indicate that TAF has a higher resistance threshold than TDF and suggest that higher resistance cutoffs should be applied for TAF compared to TDF in genotypic and phenotypic resistance algorithms.

scholarly journals Formulation and Evaluation of Meloxicam In-Situ Gel Designed for Sustained Drug Release to Reduce Dosing Frequency in the Management of Arthritis

2021 ◽  
Vol 69 (2) ◽  
Author(s):  
Meesala. Srinivasa Rao ◽  
M. S Chandra Goud ◽  
C. V. Reddy
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Sustained Drug Release ◽  
In Vitro Drug Release ◽  
In Situ Gel ◽  
Dosing Frequency ◽  
Gel Formulations

Meloxicam has short biological half-life and is rapidly eliminated, frequent oral administration is necessary to maintain its therapeutic concentration, but this can increase chances of missing dose. This makes Meloxicam a good applicant for oral sustained release formulation. The objective of study was to develop in-situ gel formulations of Meloxicam for sustained release to reduce the dosing frequency in the treatment of rheumatoid arthritis. Method of Ion sensitive in-situ gelation was used in this study. Meloxicam In-situ gel formulations were prepared by varying concentrations of sodium alginate as a bio-degradable gel forming polymer, CaCl2 as a cross-linking agent and Chitosan/ HPMCK4/HPMCK15/Guar gum/Gellan gum/ Xantha gum/pectin were used as drug release rate controlling polymers. The formulations F11-F18 were assessed for Physical appearance, pH, in-vitro drug release, viscosity, in-vitro gelling capacity and drug content. FTIR, DSC and in-vivo drug kinetics studies was conducted for Meloxicam, excipients used and optimized formulation. Formulations showed an optimum viscosity that will allow ease of administration and swallowing. All formulations are shown pH between4.7-4.9, floating lag time was 2-3sec and floated for >12 hrs. In vitro drug release studies reporting that commercially available product Meloxicam SR has showed 99.92% drug release in 8 hrs and out of eight formulations F11 showing in-vitro drug release of 99.52% over a 12hrs extended period. FTIR studies revealed no interaction between drug and excipients used. The results of In-vivo kinetic studies are approving the better performance of the optimized formulation in comparison to marketed formulation, The Cmax, Tmax, half-life AUC values are confirming the same thing. In conclusion, Formulation (F11) was selected as optimized formulations could be offered as shows optimum sustained drug release compared to commercial formulation. Hence Meloxicam containing Chitosan as drug release controll

scholarly journals Preparation and Release Profiles in Vitro/Vivo of Galantamine Pamoate Loaded Poly (Lactideco-Glycolide) (PLGA) Microspheres

2021 ◽  
Vol 11 ◽  
Author(s):  
Liping Du ◽  
Shankui Liu ◽  
Guizhou Hao ◽  
Li Zhang ◽  
Miaomiao Zhou ◽  
...  
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Drug Loading ◽  
Entrapment Efficiency ◽  
Solvent Evaporation Method ◽  
Sustained Drug Release ◽  
Water Emulsion ◽  
Oil Water

Patient’s poor compliance and the high risk of toxic effects limit the clinical use of galantamine hydrobromide. To overcome these drawbacks, the sustained-release galantamine pamoate microspheres (GLT-PM-MS) were successfully developed using an oil/water emulsion solvent evaporation method in this study. Physicochemical properties of GLT-PM-MS were carefully characterized, and the in vitro and in vivo drug release behaviors were well studied. Results showed that the morphology of optimized microspheres were spherical with smooth surfaces and core-shell interior structure. Mean particle size, drug loading and entrapment efficiency were 75.23 ± 1.79 μm, 28.01 ± 0.81% and 87.12 ± 2.71%, respectively. The developed GLT-PM-MS were found to have a sustained release for about 24 days in vitro and the plasma drug concentration remained stable for 17 days in rats. These results indicated that GLT-PM-MS could achieve the sustained drug release purpose and be used in clinical trial.

scholarly journals 1448. Forgiveness of BIC/FTC/TAF: In Vitro Simulations of Intermittent Poor Adherence Find Limited HIV-1 Breakthrough and High Barrier to Resistance

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S726-S727
Author(s):  
Andrew Mulato ◽  
Rima K Acosta ◽  
Stephen R Yant ◽  
Tomas Cihlar ◽  
Kirsten L White
Keyword(s):  
Virologic Failure ◽  
Resistance Development ◽  
Drug Concentrations ◽  
Suboptimal Adherence ◽  
Trough Concentrations ◽  
Tenofovir Alafenamide ◽  
Emergence Of Resistance ◽  
Perfect Adherence ◽  
Hiv 1

Abstract Background Short lapses in adherence to ARVs can lead to virologic failure and emergence of resistance. Previous in vitro studies of regimen “forgiveness” simulated drug exposures of perfect adherence or short-term suboptimal adherence with bictegravir+emtricitabine+tenofovir alafenamide (BIC+FTC+TAF) and with dolutegravir and lamivudine (DTG+3TC). Here, viral breakthrough (VB) and resistance development were evaluated under alternating high and low drug exposures simulating variable adherence levels. Methods Wild-type HIV-1 (IIIb)-infected MT-2 cells were exposed to drug combinations and monitored for VB. Experiments alternated between high and low drug concentrations of either BIC+FTC+TAF or DTG+3TC (Table 1). Drug concentrations for each regimen were determined using human plasma-free adjusted clinical trough concentrations (Cmin), at simulated Cmin after missing 2 or 4 consecutive doses (Cmin-2 and Cmin-4) based on drug half-lives. Emergent HIV-1 were genotyped by deep sequencing and a 2% threshold. Results In these experiments, constant drug concentrations corresponding to full adherence (Cmin) did not lead to VB. Using Cmin concentrations for one week followed by constant Cmin-2 exposures for 4 weeks, DTG+3TC had VB and emergence of M184V/I in reverse transcriptase (RT) but there was no VB for BIC+FTC+TAF. Using alternating drug exposures of Cmin (weeks 1 and 3) and Cmin-2 or Cmin -4 (weeks 2, 4, and 5), VB was not observed with BIC+FTC+TAF, and VB was decreased or delayed with DTG+3TC compared to DTG+3TC held at Cmin-2 or Cmin-4. Resistance development was observed in some cultures with VB: 1 culture with BIC+FTC+TAF had G163R in IN and 19 cultures with DTG+3TC had INSTI and RT resistance including 10 with M184V/I. Table 1. Summary of Breakthrough Frequency and Resistance Development Conclusion BIC+FTC+TAF has high in vitro forgiveness and consistent protection against emergence of drug resistance during simulations of short lapses in adherence. Higher DTG+3TC exposure, whether constant or intermittent, was better at preventing or delaying VB than lower DTG+3TC exposures, but DTG+3TC was less forgiving than BIC+FTC+TAF. Prevention of viral replication and resistance development is necessary to maintain lifelong viral suppression, particularly in the real world where drug adherence is often imperfect. Disclosures Andrew Mulato, BS, MBA, Gilead Sciences, Inc. (Employee, Shareholder) Rima K. Acosta, BS, Gilead Sciences, Inc. (Employee, Shareholder) Stephen R. Yant, PhD, Gilead Sciences, Inc. (Employee, Shareholder) Tomas Cihlar, PhD, Gilead Sciences, Inc. (Employee, Shareholder) Kirsten L. White, PhD, Gilead Sciences, Inc. (Employee, Shareholder)

Formulation and Evaluation of Itopride Hydrochloride Floating Beads for Gastroretentive Delivery

2013 ◽  
Vol 6 (4) ◽  
pp. 2269-2280
Author(s):  
Nagratna Dhople ◽  
P N Dandag ◽  
A P Gadad ◽  
C K Pandey ◽  
Masthiholimath V S
Keyword(s):  
Sustained Release ◽  
In Vitro Release ◽  
Entrapment Efficiency ◽  
Sustained Release Formulation ◽  
Prokinetic Drug ◽  
Drug Entrapment Efficiency ◽  
Itopride Hydrochloride ◽  
Vitro Release

A gastroretentive sustained release system of itopride hydrochloride was formulated to increase the gastric residence time and modulate its release behavior. Itopride hydrochloride is a prokinetic drug used in the treatment of gastroeosophageal reflux disease, Non-ulcer dyspepsia and as an antiemetic. Hence, itopride hydrochloride beads were prepared by emulsion gelation method by employing low methoxy pectin and sodium alginate as sustained release polymers in three different ratios alone and in combination and sunflower oil was used to enable floating property to the beads. The effect of variation in polymer and their concentration was investigated. The beads were evaluated for production yield, particle size, swelling index, density measurement, buoyancy, drug content, drug entrapment efficiency, in vitro release characteristics and release kinetic study. Based on drug entrapment efficiency, buoyancy, swelling and in vitro release, F9 was selected as the optimized formulation. F9 was further subjected to surface morphology by SEM, in vitro release comparison with marketed formulation, in vivo floating study in rabbits and stability study for 90 days. In vitro release follows zero order and fitted in Korsmeyer peppas model (Non-Fickian release). Therefore, the rate of drug release is due to the combined effect of drug diffusion and polymer swelling. The in vivo X-ray studies revealed that the beads were floating in the rabbit stomach up to 10 hours. Thus, it was concluded that the sustained release formulation containing itopride hydrochloride was found to improve patient compliance, minimize the side effects and decrease the frequency of administration.

Formulation and Evaluation of Atorvastatin Calcium-Poly-ε-Caprolactone Nanoparticles Loaded Ocular Inserts for Sustained Release and Antiinflammatory Efficacy

2020 ◽  
Vol 21 (15) ◽  
pp. 1688-1698
Author(s):  
Germeen N.S. Girgis
Keyword(s):  
Sustained Release ◽  
In Vitro Release ◽  
Pluronic F127 ◽  
In Vivo Study ◽  
Average Weight ◽  
Drug Release Profile ◽  
Atorvastatin Calcium ◽  
Anti Inflammatory

Purpose: The work was performed to investigate the feasibility of preparing ocular inserts loaded with Poly-ε-Caprolactone (PCL) nanoparticles as a sustained ocular delivery system. Methods: First, Atorvastatin Calcium-Poly-ε-Caprolactone (ATC-PCL) nanoparticles were prepared and characterized. Then, the optimized nanoparticles were loaded within inserts formulated with Methylcellulose (MC) and Polyvinyl Alcohol (PVA) by a solvent casting technique and evaluated physically, for in-vitro drug release profile. Finally, an in-vivo study was performed on the selected formulation to prove non-irritability and sustained ocular anti-inflammatory efficacy compared with free drug-loaded ocuserts. Results: The results revealed (ATC-PCL) nanoparticles prepared with 0.5% pluronic F127 were optimized with 181.72±3.6 nm particle size, 0.12±0.02 (PDI) analysis, -27.4± 0.69 mV zeta potential and 62.41%±4.7% entrapment efficiency. Nanoparticles loaded ocuserts manifested compatibility between drug and formulation polymers. Moreover, formulations complied with average weight 0.055±0.002 to 0.143±0.023 mg, and accepted pH. ATC-PCL nanoparticles loaded inserts prepared by 5% MC showed more sustained, prolonged in-vitro release over 24h. In-vivo study emphasized non-irritability, ocular anti-inflammatory effectiveness represented by smaller lid closure scores, and statistically significant lowering in PMN count after 3h. Conclusion: These findings proposed a possibly simple, new and affordable price technique to prepare promising (ATC-PCL) nanoparticles loaded inserts to achieve sustained release with prolonged antiinflammatory efficacy.

Development and Optimization of Sustained Release Moxifloxacin Hydrochloride Loaded Nanoemulsion for Ophthalmic Drug Delivery: A 32 Factorial Design Approach

2020 ◽  
Vol 12 ◽  
Author(s):  
Sagar R. Pardeshi ◽  
Harshal A. Mistari ◽  
Rakhi S. Jain ◽  
Pankaj R. Pardeshi ◽  
Rahul L. Rajput ◽  
...  
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Factorial Design ◽  
Water Solubility ◽  
Tween 80 ◽  
Drug Release Profile ◽  
Sustained Drug Release ◽  
Bacterial Conjunctivitis ◽  
Promising Alternative

Background: Moxifloxacin is a BCS class I drug used in the treatment of bacterial conjunctivitis and keratitis. Despite its high water solubility, it possesses limited bioavailability due to anatomical and physiological constraints associated with the eyes which required multiple administrations to achieve a therapeutic effect. Objective: In order to prolong drug release and to improve antibacterial efficacy for the treatment of bacterial keratitis and conjunctivitis, moxifloxacin loaded nanoemulsion was developed. Methods: The concentration of oil (oleic acid), surfactant (tween 80), and cosurfactant (propylene glycol) were optimized by employing a 3-level 2-factorial design of experiment for the development of nanoemulsion. The developed nanoemulsion was characterized by particle size distribution, viscosity, refractive index, pH, drug content and release, transmission electron microscopy (TEM), and antibacterial study. The compatibility of the drug with the excipients was accessed by Fourier transform infrared spectroscopy (FTIR). Result: The average globule size was found to be 198.20 nm. The TEM study reveals the globules were nearly spherical and are well distributed. In vitro drug release profile for nanoemulsion shown sustained drug release (60.12% at the end of 6 h) compared to drug solution, where complete drug released within 2 h. The antibacterial effectiveness of the drug-loaded nanoemulsion was improved against S. aureus compared with the marketed formulation. Conclusion: The formulated sustained release nanoemulsion could be a promising alternative to eye drop with improved patient compliance by minimizing dosing frequency with improved antibacterial activity.

scholarly journals Development and In Vitro-In Vivo Evaluation of a Novel Sustained-Release Loxoprofen Pellet with Double Coating Layer

Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 260 ◽  
Author(s):  
Dongwei Wan ◽  
Min Zhao ◽  
Jingjing Zhang ◽  
Libiao Luan
Keyword(s):  
Citric Acid ◽  
Drug Release ◽  
Sustained Release ◽  
Release Rate ◽  
Diffusion Rate ◽  
Immediate Release ◽  
Pharmacokinetic Studies ◽  
Release Tablet

This study aimed to develop a novel sustained release pellet of loxoprofen sodium (LXP) by coating a dissolution-rate controlling sub-layer containing hydroxypropyl methyl cellulose (HPMC) and citric acid, and a second diffusion-rate controlling layer containing aqueous dispersion of ethyl cellulose (ADEC) on the surface of a LXP conventional pellet, and to compare its performance in vivo with an immediate release tablet (Loxinon®). A three-level, three-factor Box-Behnken design and the response surface model (RSM) were used to investigate and optimize the effects of the citric acid content in the sub-layer, the sub-layer coating level, and the outer ADEC coating level on the in vitro release profiles of LXP sustained release pellets. The pharmacokinetic studies of the optimal sustained release pellets were performed in fasted beagle dogs using an immediate release tablet as a reference. The results illustrated that both the citric acid (CA) and ADEC as the dissolution- and diffusion-rate controlling materials significantly decreased the drug release rate. The optimal formulation showed a pH-independent drug release in media at pH above 4.5 and a slightly slow release in acid medium. The pharmacokinetic studies revealed that a more stable and prolonged plasma drug concentration profile of the optimal pellets was achieved, with a relative bioavaibility of 87.16% compared with the conventional tablets. This article provided a novel concept of two-step control of the release rate of LXP, which showed a sustained release both in vitro and in vivo.

scholarly journals 1592U89, a novel carbocyclic nucleoside analog with potent, selective anti-human immunodeficiency virus activity.

1997 ◽  
Vol 41 (5) ◽  
pp. 1082-1093 ◽  
Author(s):  
S M Daluge ◽  
S S Good ◽  
M B Faletto ◽  
W H Miller ◽  
M H St Clair ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Oral Bioavailability ◽  
Human Peripheral Blood ◽  
Cross Resistance ◽  
Immunodeficiency Virus ◽  
Carbocyclic Nucleoside ◽  
Hiv 1 ◽  
In Cells

1592U89, (-)-(1S,4R)-4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]-2-cyclo pentene-1-methanol, is a carbocyclic nucleoside with a unique biological profile giving potent, selective anti-human immunodeficiency virus (HIV) activity. 1592U89 was selected after evaluation of a wide variety of analogs containing a cyclopentene substitution for the 2'-deoxyriboside of natural deoxynucleosides, optimizing in vitro anti-HIV potency, oral bioavailability, and central nervous system (CNS) penetration. 1592U89 was equivalent in potency to 3'-azido-3'-deoxythymidine (AZT) in human peripheral blood lymphocyte (PBL) cultures against clinical isolates of HIV type 1 (HIV-1) from antiretroviral drug-naive patients (average 50% inhibitory concentration [IC50], 0.26 microM for 1592U89 and 0.23 microM for AZT). 1592U89 showed minimal cross-resistance (approximately twofold) with AZT and other approved HIV reverse transcriptase (RT) inhibitors. 1592U89 was synergistic in combination with AZT, the nonnucleoside RT inhibitor nevirapine, and the protease inhibitor 141W94 in MT4 cells against HIV-1 (IIIB). 1592U89 was anabolized intracellularly to its 5'-monophosphate in CD4+ CEM cells and in PBLs, but the di- and triphosphates of 1592U89 were not detected. The only triphosphate found in cells incubated with 1592U89 was that of the guanine analog (-)-carbovir (CBV). However, the in vivo pharmacokinetic, distribution, and toxicological profiles of 1592U89 were distinct from and improved over those of CBV, probably because CBV itself was not appreciably formed from 1592U89 in cells or animals (<2%). The 5'-triphosphate of CBV was a potent, selective inhibitor of HIV-1 RT, with Ki values for DNA polymerases (alpha, beta, gamma, and epsilon which were 90-, 2,900-, 1,200-, and 1,900-fold greater, respectively, than for RT (Ki, 21 nM). 1592U89 was relatively nontoxic to human bone marrow progenitors erythroid burst-forming unit and granulocyte-macrophage CFU (IC50s, 110 microM) and human leukemic and liver tumor cell lines. 1592U89 had excellent oral bioavailability (105% in the rat) and penetrated the CNS (rat brain and monkey cerebrospinal fluid) as well as AZT. Having demonstrated an excellent preclinical profile, 1592U89 has progressed to clinical evaluation in HIV-infected patients.

Sign in / Sign up

Export Citation Format

Share Document