Mixed Pluronic/lecithin micelles formulation for oral bioavailability of candesartan cilexetil drug: in vitro characterization and in vivo pharmacokinetic investigations.

OBJECTIVE: This study aimed to develop a mixed polymeric micelle formulation incorporating candesartan cilexetil (CAND) drug to enhance its oral bioavailability for the better treatment of hypertension. METHODS: A Box-Behnken design was utilized to optimize the CAND-incorporated mixed polymeric micelles formulation (CAND-PFLC) consisting of Pluronics (P123 and F68) and lecithin (LC). The optimized CAND-PFLC micelles formulation was characterized for size, shape, zeta potential, polydispersity index (PDI), and entrapment efficiency (%EE). An in vitro release study, ex vivo permeability investigation, and an in vivo pharmacokinetic analysis were carried out to evaluate the performance of the formulation. RESULTS: The optimized CAND-PFLC micelles formulation demonstrated a spherical shape, a particle size of 44 ± 2.03 nm, a zeta potential of -7.07 ± 1.39 mV, a PDI of 0.326 ± 0.06, and an entrapment efficiency of 87 ± 3.12%. The formulation exhibited excellent compatibility, better stability, and a noncrystalline nature. An in vitro release study revealed a faster drug release of 7.98% at gastric pH in 2 hrs and 94.45% at intestinal pH within 24 hrs. The ex vivo investigation demonstrated a significantly enhanced permeability of CAND, with 94.86% in the micelle formulation compared to 9.03% of the pure drug. In vivo pharmacokinetic analysis showed a 4.11-fold increase in oral bioavailability of CAND compared to the marketed formulation. CONCLUSION: The CAND-PFLC mixed micelle formulation demonstrated improved performance compared to pure CAND, indicating its potential as a promising oral drug delivery system for the effective treatment of hypertension.

Current veterinary regulations and way ahead.

This article aims to perform a comparative systematic review of regulations in veterinary medicine between the years 2016 to 2023. It explores the complex web of veterinary medicine regulations in various agencies and the nations, including USA (United States of America), EU (European Union), UK (United Kingdom), Japan, Australia, and India. Current article provides the comparative study on the veterinary regulations of different countries, including acts, directives, and drug approval processes. Such as, the specific legislation is needed to address zoonotic diseases. The strategic and regulated stockpiling of the veterinary drugs especially in chronic veterinary disease outbreak. It is essential to develop the dedicated Veterinary Pharmacopoeia for the regulated standardization of the raw materials as well as the formulations. Veterinary medical device is a field which is highly unregulated. There is a need to have regulations for the same. It is important to have dedicated veterinary pharmacovigilance centers which help in improving quality of medications to the livestock farms. After comparing the regulations of different countries. We observed that there is the absence of the zoonotic diseases and pharma stockpiling in every country. There is also an absence of the dedicated veterinary pharmacopoeia in every country. USA and Australia have the veterinary medical device regulation which is not there in other countries. Around the globe only Australia has the dedicated pharmacovigilance center. Including these recommendations into regulatory framework enhances the quality and safety of veterinary medicine. The current article adds a valuable resource for policymakers, veterinarians, and stakeholders in the field of animal health care.

Optimization of Lurasidone HCl-Loaded PLGA Nanoparticles for Intramuscular Delivery: Enhanced Bioavailability, Reduced Dosing Frequency, Pharmacokinetics, and Therapeutic Outcomes.

This study aimed to develop a nanoparticle drug delivery system using poly (lactic-co-glycolic acid) (PLGA) for enhancing the therapeutic efficacy of lurasidone hydrochloride (LH) in treatment of schizophrenia through intramuscular injection. LH-loaded PLGA nanoparticles (LH-PNPs) were prepared using the nanoprecipitation technique and their physicochemical characteristics were assessed. Particle size (PS), zeta potential, morphology, % encapsulation efficiency, % drug loading, drug content, and solid-state properties were analyzed. Stability, in vitro release, and in vivo pharmacokinetic studies were conducted to evaluate the therapeutic efficacy of the developed LH-PNPs. The optimized batch of LH-PNPs exhibited a narrow and uniform PS distribution before and after lyophilization, with sizes of 112.7 ± 1.8 nm and 115.0 ± 1.3 nm, respectively, and a low polydispersity index. The PNPs showed high drug entrapment efficiency, drug loading, and drug content uniformity. Solid-state characterization indicated good stability and compatibility, with a nonamorphous state. The drug release profile demonstrated sustained release behavior. Intramuscular administration of LH-PNPs in rats resulted in a significantly prolonged mean residence time compared with the drug suspension. These findings highlight that intramuscular delivery of the LH-PNP formulation is a promising approach for enhancing the therapeutic efficacy of LH in treatment of schizophrenia.

Ti3C2Tx nanosheet@Cu/Fe-MOF separators for high-performance lithium-sulfur batteries: an experimental and density functional theory study.

Lithium-sulfur (Li-S) batteries have attracted much attention due to their superior theoretical specific capacity and high theoretical energy density. However, rapid capacity fading originating from the shuttle effect, insulating the S cathode and the dendrite formation on the Li anode restrict the practical applications of Li-S batteries. Herein, we suggest novel coatings on glass fiber separators to satisfy all high-performance Li-S battery requirements. A conductive Ti3C2Tx (MXene) nanosheet/Fe-MOF or Ti3C2Tx (MXene) nanosheet/Cu-MOF layer was coated on a glass fiber separator to act as a polysulfide trapping layer. The MXene layer with high conductivity and polar surface functional groups could confine polysulfides and accelerate the redox conversions. The porous MOF layer acts as a Li ion sieve, thereby leading to the interception of polysulfides and mitigation of Li dendrite growth. The cells with the Cu-MOF/MXenes and Fe-MOF/MXene separators display superior capacities of 1100 and 1131 mA h g-1 after 300 cycles, respectively, whereas the cell with a pure glass fiber separator delivers a very low capacity of 309 mA h g-1 after 300 cycles. With Fe-MOF/MXene and Cu-MOF/MXene configurations, the discharge capacity, coulombic efficiency, cycling stability, and electrochemical conversion reactions are significantly improved. Our ab initio calculations demonstrate that the MXene layer dissociates lithium polysulfides into adsorbed S and mobile Li ions, which explains the experimental findings.

Design, Development, and Evaluation of SA-F127:TPGS Polymeric Mixed Micelles for Improved Delivery of Glipizide Drug: In-vitro, Ex-vivo, and In-vivo Investigations.

The anti-diabetic glipizide (GLN) drug has notable pharmaceutical advantages, but poor aqueous solubility restricts its wide applications. The present work was to develop a mixed polymeric micelle system composed of SA-F127 and TPGS to improve the water solubility and effective delivery of the GLN. First, we synthesized SA-F127 and confirmed it through FTIR, NMR, and GPC techniques. The GLN-PMM were fabricated with the thin-film technique and optimized with CCD design. The developed GLN-PMM was characterized using DLS, Zeta, TEM, Rheology, FTIR, DSC, and XRD measurements. The GLN-PMM manifested a spherical morphology with 67.86 nm particle size, a -3.85 mV zeta potential, and a 0.582±0.06 PDI value. The polymeric mixed micelles showed excellent compatibility with GLN and were amorphous in nature. NMR studies confirmed the encapsulation of GLN in the core of the mixed micelle. In addition, the GLN-PMM micelles were tested in vitro for cumulative drug release, ex vivo for permeation, and in vivo for anti-diabetic investigations. The GLN-PMM release profile in the various pH environments showed over 90% after 24 h, clearly indicating sustained release. The GLN-PMM micelles gave higher 88.86±3.39% GLN permeation from the goat intestine compared with free GLN. In-vivo anti-diabetic investigation proves the powerful anti-diabetic properties of GLN-PMM in comparison to the marketed formulation. These findings demonstrated that the polymeric mixed micelles of SA-F127 and TPGS could be a promising, effective, and environment-friendly approach for oral delivery of the GLN.

α-Methylbenzylamine Functionalized Crown-Ether-Appended Calix[4]arene Phase Transfer Catalyst for Enantioselective Henry Reaction.

In this letter, we designed a highly selective α-methylbenzylamine functionalized crown-ether-appended calix[4]arene derived phase transfer catalyst for asymmetric nitroaldol reaction to provide the desired nitroaldol adducts in high yields (up to 99 % yield) with good to excellent enantioselectivities (up to 99.8 % ee).

A simple and straightforward strategy for expedient access to benzoxazoles using chemically engineered 2D magnetic graphene oxide nanosheets as an eco-compatible catalyst.

Two-dimensional (2D) graphene oxide nanosheets serve as an excellent support material for immobilizing metal complexes to deal with the drawbacks of homogeneous catalysis. In this work, we report a magnetically retrievable graphene oxide (MGO) based copper nanocatalytic system that has been efficiently exploited for obtaining a series of pharmaceutically and biologically active benzoxazole scaffolds. The nanocatalyst was designed by covalent immobilization of dehydroacetic acid (DHA) onto a magnetic amino-silanized graphene oxide nanosupport which was accompanied by its metallation with copper acetate. The structure of the synthesized MGO hybrid material (Cu@DHA@APTES@MGO) was characterized by numerous physico-chemical techniques such as transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometry (VSM), elemental mapping, atomic absorption spectroscopy (AAS), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) surface area analysis and energy-dispersive X-ray fluorescence spectroscopy (ED-XRF). The fabricated architectures exhibited high efficiency for cyclization of 2-aminophenols and ß-diketones with wide substrate scope, excellent functional group tolerance, a higher conversion percentage (>98%) and a high turnover number (TON). The exceptional catalytic activity could be attributed to the 2D architecture of graphene oxide which provides space for trapping of reactants between 2D graphitic overlayers and metal surfaces and the reaction proceeds to afford benzoxazole products with moderate to excellent conversion percentages. Notably, this nanocomposite could be recovered easily through an external magnetic force and reused for multiple runs without any appreciable loss in its catalytic efficacy.

Unleashing the photocatalytic potential of a noble-metal-free heteroleptic copper complex-based nanomaterial for an enhanced aza-Henry reaction.

In this work, we fabricated a versatile and noble metal free copper-based heterogeneous photocatalyst, representing a green shift away from precious group metals such as Ir, Ru, Pt, which have been widely utilized as photocatalysts. The successfully synthesized and characterized copper photocatalyst was employed to establish a cross dehydrogenative coupling via C-H activation between tertiary amines and carbon nucleophiles. The highly efficient copper-based photocatalyst was characterized by numerous physico-chemical techniques, which confirmed its successful formation as well as its high activity. Inductively coupled plasma (ICP-OES) analysis revealed that the composite Cu@Xantphos@ASMNPs had a very high loading of 0.423 mmol g-1 of copper. The magnetic Cu@Xantphos@ASMNPs were utilized as a potential heterogeneous photocatalyst for the very facile and regioselective conversion of aryl tetrahydroqinoline to the respective nitroalkyl aryl tetrahydroisoquinoline in high yield using air as an oxidant and methanol as a green solvent with irradiation with visible light under mild reaction conditions. Additionally, the catalyst shows exceptional chemical stability and reusability without any agglomeration even after several cycles of use, which is one of the key features of this material, rendering it a potential candidate from economic and environmental perspectives.

Isothiocyanates as potential antifungal agents: a mini-review.

Cruciferous vegetables and mustard oil are rich in the glucosinolate group of molecules. Isothiocyanates are an important group of glucosinolate derivatives. These derivatives have various bioactive properties, including antioxidant, antibacterial, anticarcinogenic, antifungal, antiparasitic, herbicidal and antimutagenic activity. Previous studies indicate that regular intake of such vegetables may considerably reduce the incidence of various types of cancer. These studies have inspired studies where the bioactive agents of these plants have been isolated and explored for their therapeutic applications. The use of these bioactive compounds as antifungals could be a new therapeutic approach against human pathogenic fungi. Isothiocyanates have been studied for their antifungal activity and have the potential to be used for antifungal therapy.

Vegetables like cabbage, cauliflower and broccoli have a distinct flavor because of chemicals called glucosinolates. Whenever we cut and eat these vegetables, glucosinolates are broken down into isothiocyanates. Glucosinolates and isothiocyanates have health benefits because they stop the growth of bacteria, parasites and fungi that cause disease, such as Candida albicans. They may also prevent cancer, as regularly eating these vegetables has been shown to reduce the development of some types of cancer in humans. Investigation is needed to explore how glucosinolates and isothiocyanates could be used to treat fungal infections.

Cellular metabolic activity and electrochemical stability assay of embedded oxidoreductase enzyme confined in the nanospace of a framework exoskeleton.

In the present study, we sought to reveal how embedding oxidoreductase enzymes in a metal-organic framework influences restoring the biofunctionality when encapsulated within zeolitic imidazolate framework (ZIF-8 and ZIF-90), wherein these biocomposites were explored for their cellular metabolic activity using the (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) (MTT) assay on A549 lung cancer cells and NIH3T3 (mouse fibroblasts) cells. We chose two biocomposites, namely catalase-encapsulated ZIF-8 and ZIF-90, wherein the enzyme was encapsulated at varied loadings through a rapid self-triggered nucleation around the protein surfaces of the enzyme. Interestingly, this embedding pattern of catalase in both ZIF-8 and ZIF-90 depended on the surface chemistry of the enzyme. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy analysis revealed the stability of the encapsulated enzyme in the nanospace of the ZIF-8 and ZIF-90 frameworks. Investigation of the cellular metabolic activity by the MTT assay of Cat@ZIF-8 and Cat@ZIF-90 on the lung cancer cell A549 showed cell viability enhancement in the case of Cat@ZIF-8 at a higher percentage compared to that of Cat@ZIF-90. A similar metabolic activity assay was performed with the internalization of Cat@ZIF-90 for NIH3T3 (mouse fibroblasts) cells. The revealed difference between the MOF compounds was due to the nano-confinement effect in ZIF-8 compared to ZIF-90, which can accelerate the utilization in cellar metabolic activity.

Enantioselective Alkylation of Glycine Imines Using a Cinchona-Functionalized Crown Ether-Strapped Calixarene Phase-Transfer Catalyst.

We report a class of quaternary ammonium Cinchona-functionalized crown ether-strapped calix[4]arene phase-transfer catalysts for the efficient enantioselective α-alkylation of glycine imines. The catalyst exhibits excellent catalytic performance at 0.1 mol % catalytic loading, affording the desired α-alkylated glycinates with 98% yield and 99.9% ee. The catalyst could be recovered and recycled up to 30 test cycles without a significant drop in activity.

Preparation and characterization of the h-BN/Fe3O4/APTES-AMF/CuII nanocomposite as a new and efficient catalyst for the one-pot three-component synthesis of 2-amino-4-aryl(or heteroaryl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles.

The intriguing features of surface-engineered hexagonal two-dimensional boron nitride (h-BN) nanostructures have captivated the immense interest of researchers working in the arena of materials science. Inspired by striking attributes exhibited by h-BN nanosheets as the support material, we devoted our efforts towards synthesizing a novel magnetically retrievable h-BN/Fe3O4/APTES-AMF/CuII catalytic system, which was then comprehensively characterized using various techniques including SEM, TEM, EDX, SEM-based elemental mapping, ED-XRF, AAS, XRD, FT-IR, VSM, XPS, TGA, and BET. Further, the catalytic potential of h-BN/Fe3O4/APTES-AMF/CuII nanocomposites was investigated in the one-pot multicomponent coupling reaction to gain access to a library of biologically active 2-amino-4-aryl(or heteroaryl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles under ambient conditions. In addition, the use of green solvent, facile magnetic recoverability, and reusability of up to six successive runs made this protocol environmentally benign and economical. This work throws light on the development of covalently functionalized 2D-BN nanostructure-based copper catalysts and establishes its significance in furnishing industrially demanding products that would pave the way towards sustainable chemistry.

Impact of gadolinium doping into the frustrated antiferromagnetic lithium manganese oxide spinel.

Cubic spinel LiMn2O4 (LMO) are promising electrode materials for advanced technological devices owing to their rich electrochemical properties. Here, a series of Gd3+-doped LiMn2O4 were synthesized using a simple one-step sol-gel synthesis, and a systematized study on the effect of increasing Gd3+ concentration on magnetic properties is conferred. The Raman and density functional theory (DFT) calculations of the synthesized materials were correlated with the magnetic properties; we observed a high coercivity value for the doped LMO compared to pristine LMO, which scales down from 0.57T to 0.14T with an increase in Gd concentration. The samples exhibited paramagnetic (at 300K) to antiferromagnetic (at 5K) transition and variation in the magnetic moment due to the replacement of Mn+2 or Mn+3 ion by Gd+3 ion from the octahedral 16d lattice site. The observed phase transitions in the hysteresis curve below the Neel temperature (TN) at 5K are found to be due to the superexchange mechanism.

Microwave-assisted multicomponent synthesis of antiproliferative 2,4-dimethoxy-tetrahydropyrimido[4,5-b]quinolin-6(7H)-ones.

In this study, we demonstrate a simple, highly efficient, rapid and convenient series of 2,4-dimethoxy-tetrahydropyrimido[4,5-b]quinolin-6(7H)-ones 4a-v. Microwave irradiation facilitates the one-pot multicomponent reaction of different aromatic aldehydes, 6-amino-2,4-dimethoxypyrimidine and dimedone using glacial acetic acid. Metal-free multicomponent synthesis, shorter reaction time, higher product yield, easy product purification without column chromatography and outstanding green credential parameters are the key features of this protocol. We analysed 4a-v against six human tumour cell lines for antiproliferative activity. 4h, 4o, 4q and 4v show good antiproliferative activity with a good in silico ADMET profile. Furthermore, 4h, 4o, 4q and 4v also show drug-likeness properties by obeying drug-like filters.

Biopolymeric Nanocarriers for Nutrient Delivery and Crop Biofortification.

Driven by the possibility of precise transformational change in nutrient-enrichment technology to meet global food demand, advanced nutrient delivery strategies have emerged to pave the path toward success for nutrient enrichment in edible parts of crops through bioderived nanocarriers with increased productivity. Slow and controlled release of nutrient carrier materials influences the nutrient delivery rate in soil and in the edible parts of crops with a sluggish nutrient delivery to enhance their availability in roots by minimizing nutrient loss. With a limited understanding of the nutrient delivery mechanism in soil and the edible parts of crops, it is envisaged to introduce nutrient-enrichment technology for nutrient delivery that minimizes environmental impact due to its biodegradable nature. This article attempts to analyze the possible role of the cellulose matrix for nutrient release and the role of cellulose nanocomposites and nanofibers. We have proposed a few cellulose derived biofortificant materials as nutrient carriers, such as (1) nanofibers, (2) polymer-nanocellulose-clay composites, (3) silk-fibroin derived nanocarriers, and (4) carboxymethyl cellulose. An effort is undertaken to describe the research need by linking a biopolymer derived nanocarrier for crop growth regulation and experimental nitrogen release analysis. We have finally provided a perspective on cellulose nanofibers (CNFs) for microcage based nutrient loading ability. This article aims to explain why biopolymer derived nutrient carriers are the alternative candidate for alleviating nutrient deficiency challenges which are involved in focusing the nutrient delivery profile of biopolymers and promising biofortification of crops.

Development of Electrode-Supported Proton Conducting Solid Oxide Cells and their Evaluation as Electrochemical Hydrogen Pumps.

Protonic ceramic solid oxide cells (P-SOCs) have gained widespread attention due to their potential for operation in the temperature range of 300-500 °C, which is not only beneficial in terms of material stability but also offers unique possibilities from a thermodynamic point of view to realize a series of reactions. For instance, they are ideal for the production of synthetic fuels by hydrogenation of carbon dioxide and nitrogen, upgradation of hydrocarbons, or dehydrogenation reactions. However, the development of P-SOC is quite challenging because it requires a multifront optimization in terms of material synthesis and fabrication procedures. Herein, we report in detail a method to overcome various fabrication challenges for the development of efficient and robust electrode-supported P-SOCs (Ni-BCZY/BCZY/Ni-BCZY) based on a BaCe0.2Zr0.7Y0.1O3-δ (BCZY271) electrolyte. We examined the effect of pore formers on the porosity of the Ni-BCZY support electrode, various electrolyte deposition techniques (spray, spin, and vacuum-assisted), and thermal treatments for developing robust and flat half-cells. Half-cells containing a thin (10-12 µm) pinhole-free electrolyte layer were completed by a screen-printed Ni-BCZY electrode and evaluated as an electrochemical hydrogen pump to access the functionality. The P-SOCs are found to show a current density ranging from 150 to 525 mA cm-2 at 1 V over an operating temperature range of 350-450 °C. The faradaic efficiency of the P-SOCs as well as their stability were also evaluated.

Experimental and computational studies on the Cinchona anchored calixarene catalysed asymmetric Michael addition reaction.

Lower-rim Cinchona anchored calix[4]arene cationic catalysts were developed for asymmetric Michael addition of acetylacetone to ß-nitrostyrenes. The desired Michael adducts were formed with high yields and enantioselectivities. Density functional theory investigations throw light on the catalyst-substrate interaction and the reaction mechanism.

Observation and rationalization of nitrogen oxidation enabled only by coupled plasma and catalyst.

Heterogeneous catalysts coupled with non-thermal plasmas (NTP) are known to achieve reaction yields that exceed the contributions of the individual components. Rationalization of the enhancing potential of catalysts, however, remains challenging because the background contributions from NTP or catalysts are often non-negligible. Here, we first demonstrate platinum (Pt)-catalyzed nitrogen (N2) oxidation in a radio frequency plasma afterglow at conditions at which neither catalyst nor plasma alone produces significant concentrations of nitric oxide (NO). We then develop reactor models based on reduced NTP- and surface-microkinetic mechanisms to identify the features of each that lead to the synergy between NTP and Pt. At experimental conditions, NTP and thermal catalytic NO production are suppressed by radical reactions and high N2 dissociation barrier, respectively. Pt catalyzes NTP-generated radicals and vibrationally excited molecules to produce NO. The model construction further illustrates that the optimization of productivity and energy efficiency involves tuning of plasma species, catalysts properties, and the reactor configurations to couple plasma and catalysts. These results provide unambiguous evidence of synergism between plasma and catalyst, the origins of that synergy for N2 oxidation, and a modeling approach to guide material selection and system optimization.

Understanding the endocrine disruptor and determination of bisphenol A by functional Cu-BTABB-MOF/rGO composite as facile rapid electrochemical sensor: an experimental and DFT investigation.

A pioneering CuBTABB-MOF/rGO composite customized electrode is fabricated and utilized as a sensor towards identifying bisphenol A (BPA) in a phosphate buffer solution of pH 7.0. The composite is characterized by FTIR, Raman spectroscopy, XRD, SEM, EDX, HRTEM, and XPS to study its structural and morphological properties. Compared with Cu-BTABB-MOF and Cu-BTABB-MOF@GO, the Cu-BTABB-MOF@rGO modified electrode is more sensitive and selective to BPA due to a strong interaction between them. The developed Cu-BTABB-MOF@rGO modified electrode exhibits good sensitivity (6.95 × 10-5 A mol-1 L-1) for BPA having a wide linear range of 0-100 µmol L-1 with the LOD of 2.08 × 10-5 mol L-1, reproducibility of 4.35%, and relative standard deviation (RSD) and stability of 90% for thirty days. In addition, the developed electrocatalyst remained unoccupied from interfering substances and consequently provided an encouraging platform for swift detection of BPA in real samples such as pond water and packed water bottles. Additionally, we utilized DFT (density functional theory) to model GO and Cu-BTABB-MOF structures for detecting BPA molecules.

Post-Vasectomy Semen Analysis: Optimizing Laboratory Procedures and Test Interpretation through a Clinical Audit and Global Survey of Practices.

PURPOSE: The success of vasectomy is determined by the outcome of a post-vasectomy semen analysis (PVSA). This article describes a step-by-step procedure to perform PVSA accurately, report data from patients who underwent post vasectomy semen analysis between 2015 and 2021 experience, along with results from an international online survey on clinical practice. MATERIALS AND METHODS: We present a detailed step-by-step protocol for performing and interpretating PVSA testing, along with recommendations for proficiency testing, competency assessment for performing PVSA, and clinical and laboratory scenarios. Moreover, we conducted an analysis of 1,114 PVSA performed at the Cleveland Clinic's Andrology Laboratory and an online survey to understand clinician responses to the PVSA results in various countries. RESULTS: Results from our clinical experience showed that 92.1% of patients passed PVSA, with 7.9% being further tested. A total of 78 experts from 19 countries participated in the survey, and the majority reported to use time from vasectomy rather than the number of ejaculations as criterion to request PVSA. A high percentage of responders reported permitting unprotected intercourse only if PVSA samples show azoospermia while, in the presence of few non-motile sperm, the majority of responders suggested using alternative contraception, followed by another PVSA. In the presence of motile sperm, the majority of participants asked for further PVSA testing. Repeat vasectomy was mainly recommended if motile sperm were observed after multiple PVSA's. A large percentage reported to recommend a second PVSA due to the possibility of legal actions. CONCLUSIONS: Our results highlighted varying clinical practices around the globe, with controversy over the significance of non-motile sperm in the PVSA sample. Our data suggest that less stringent AUA guidelines would help improve test compliance. A large longitudinal multi-center study would clarify various doubts related to timing and interpretation of PVSA and would also help us to understand, and perhaps predict, recanalization and the potential for future failure of a vasectomy.