Displaying publications 41 - 60 of 64 in total

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  1. Xue Y, Zhang W, Lei Y, Dang M
    J Pharm Sci, 2020 05;109(5):1714-1724.
    PMID: 32007507 DOI: 10.1016/j.xphs.2020.01.022
    Olopatadine HCl is an antiallergic drug used for the management of allergic conjunctivitis. Currently, it is delivered via eye drop solution, which is highly inefficient due to low bioavailability. Silicone contact lenses can be used to sustain the release of ophthalmic drugs. However, the presence of drug alters the optical transmittance and physical properties of the contact lens. The objective was to design a novel polyvinyl pyrrolidone (PVP)-coated olopatadine-ethyl cellulose microparticles-laden doughnut contact lens to sustained ocular delivery with limited alteration to the optical and swelling properties of the contact lens. The doughnut was implanted within the periphery of the lens using modified casting technique. Olopatadine HCl was loaded by soaking (SM-OL), direct loading (DL-OL), and doughnut casting method (DNT-OL). PVP (comfort agent) was loaded on the surface of contact lens for all the batches via novel curing technique. The in vitro olopatadine HCl release data of SM-OL (up to 48-72 h) and DL-OL batches (up to 72 h) showed high burst release, whereas DNT-OL batch showed sustained release up to 120 h without significant (p > 0.05) alteration in the optical and swelling properties of contact lens. All the batches showed sustained release of PVP up to 120 h. The in vivo studies in the rabbit tear fluid showed improvement in the olopatadine HCl and PVP retention time in comparison to eye drop solution. The PVP-loaded DNT-OL-500 lens showed tear stabilization (comfort wear) in Schirmer strip test (rabbits) with no protein adherence in comparison to DNT-OL-500 lens without PVP. The study demonstrated the successful delivery of olopatadine HCl and PVP-K30 from the doughnut contact lens for the extended period with limited alteration to the optical and swelling properties of contact lens.
    Matched MeSH terms: Povidone
  2. Abd Jalil SN, Wang DK, Yacou C, Motuzas J, Smart S, Diniz da Costa JC
    Materials (Basel), 2016 Nov 18;9(11).
    PMID: 28774057 DOI: 10.3390/ma9110938
    This work investigates the structural formation and analyses of titania membranes (TM) prepared using different vacuum exposure times for molecular weight (MW) cut-off performance and oil/water separation. Titania membranes were synthesized via a sol-gel method and coated on macroporous alumina tubes followed by exposure to a vacuum between 30 and 1200 s and then calcined at 400 °C. X-ray diffraction and nitrogen adsorption analyses showed that the crystallite size and particle size of titania increased as a function of vacuum time. All the TM membranes were mesoporous with an average pore diameter of ~3.6 nm with an anatase crystal morphology. Water, glucose, sucrose, and polyvinylpyrrolidone with 40 and 360 kDa (PVP-40 kDa and PVP-360 kDa) were used as feed solutions for MW cut-off and hexadecane solution for oil filtration investigation. The TM membranes were not able to separate glucose and sucrose, thus indicating the membrane pore sizes are larger than the kinetic diameter of sucrose of 0.9 nm, irrespective of vacuum exposure time. They also showed only moderate rejection (20%) of the smaller PVP-40 kDa, however, all the membranes were able to obtain an excellent rejection of near 100% for the larger PVP-360 kDa molecule. Furthermore, the TM membranes were tested for the separation of oil emulsions with a high concentration of oil (3000 ppm), reaching high oil rejections of more than 90% of oil. In general, the water fluxes increased with the vacuum exposure time indicating a pore structural tailoring effect. It is therefore proposed that a mechanism of pore size tailoring was formed by an interconnected network of Ti-O-Ti nanoparticles with inter-particle voids, which increased as TiO₂ nanoparticle size increased as a function of vacuum exposure time, and thus reduced the water transport resistance through the TM membranes.
    Matched MeSH terms: Povidone
  3. Haq F, Farid A, Ullah N, Kiran M, Khan RU, Aziz T, et al.
    Environ Res, 2022 Dec;215(Pt 1):114241.
    PMID: 36100100 DOI: 10.1016/j.envres.2022.114241
    This study is based on the removal of methylene blue (MB) from aqueous solution by cost effective and biodegradable adsorbent carboxymethyl starch grafted polyvinyl pyrolidone (Car-St-g-PVP). The Car-St-g-PVP was synthesized by grafting vinyl pyrolidone onto carboxymethyl starch by free radical polymerization reaction. The structure and different properties of Car-St-g-PVP were determined by 1H NMR, FT-IR, XRD, TGA and SEM. A series of batch experiments were conducted for the removal of MB, The adsorption affecting factors such as temperature, contact time, initial concentration of MB dye, dose of Car-St-g-PVP and pH were studied in detail. The other parameters like the thermodynamic study, kinetics and isothermal models were fitted to the experimental data. The results showed that pseudo 2nd order kinetics and Langmuir's adsorption isotherms were best fitted to experimental data with regression coefficient R2 viz. 0.99 and 0.97. The kinetic study showed that the adsorption mechanism favored chemisorption. The Gibbs free energy (ΔG°) for the adsorption process was found to be -7.31 kJ/mol, -8.23 kJ/mol, -9.00 kJ/mol and -10.10 kJ/mol at 25 °C, 35 °C, 45 °C and 55 °C respectively. The negative values of ΔG° suggested the spontaneous nature of the adsorption process. Similarly, the positive values of entropy (ΔS°) and enthalpy (ΔH°) 91.27 J/k.mol and 19.90 kJ/mol showed the increasing randomness and endothermic nature of the adsorption process. The value of separation factor (RL) was found to be less than one (RL 
    Matched MeSH terms: Povidone
  4. Yee W, Kumar JN, Muthusamy PD
    Indian J Microbiol, 2018 Mar;58(1):109-113.
    PMID: 29434405 DOI: 10.1007/s12088-017-0698-5
    2-mercaptoethanol (2-ME), alongside polyvinylpyrrolidone is commonly used in plant DNA extractions to deal with polyphenols, which could interfere with extraction and downstream applications. 2-ME is also commonly used to denature proteins and nucleases, especially RNAses. On the contrary, we found that the presence of 2-ME in lysis buffer interfered with DNA extraction from 12 strains of freshwater microalgae, resulting in DNA with poor integrity. We also found that the TNES-urea buffer, commonly used for preservation and DNA extraction from fish, appears as effective as the SDS and CTAB buffer for some microalgae strains. Results from our study suggests that the inclusion of 2-ME in DNA extraction protocols may be detrimental for isolation of good quality DNA from freshwater microalgae, and therefore recommend eliminating it or testing varying concentrations of 2-ME when developing species-specific extraction protocols for microalgae.
    Matched MeSH terms: Povidone
  5. Koh PT, Chuah JN, Talekar M, Gorajana A, Garg S
    Indian J Pharm Sci, 2013 May;75(3):291-301.
    PMID: 24082345 DOI: 10.4103/0250-474X.117434
    The aim of this study was to enhance the dissolution rate of efavirenz using solid dispersion systems (binary and ternary). A comparison between solvent and fusion method was also investigated. Solid dispersions of efavirenz were prepared using polyethylene glycol 8000, polyvinylpyrrolidone K30 alone and combination of both. Tween 80 was incorporated to obtain a ternary solid dispersion system. Dissolution tests were conducted and evaluated on the basis of cumulative percentage drug release and dissolution efficiency. Physicochemical characterizations of the solid dispersions were carried out using differential scanning calorimetric, powder X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. Dissolution was remarkably improved in both systems compared to pure efavirenz (P<0.05). An optimum ratio was identified at a drug:polymer of 1:10. Incorporation of Tween 80 to 1:10 formulations formed using solvent method showed further improvement in the dissolution rate. Physicochemical characterization results suggested that efavirenz existed in the amorphous form in all the solid dispersion systems providing evidence of improvement in dissolution. No statistically significant difference (P>0.05) in dissolution was observed between the two methods. Binary and ternary solid dispersion systems both have showed a significant improvement in the dissolution rate of efavirenz. Formulations with only polyvinylpyrrolidone K30 showed best dissolution profile and 1:10 was identified as an optimum drug-polymer weight ratio.
    Matched MeSH terms: Povidone
  6. Nair RS, Nair S
    Curr Drug Deliv, 2015;12(5):517-23.
    PMID: 25675336
    Mortality rate due to heart diseases increases dramatically with age. Captopril is an angiotensin converting enzyme inhibitor (ACE) used effectively for the management of hypertension. Due to short elimination half-life of captopril the oral dose is very high. Captopril is prone to oxidation and it has been reported that the oxidation rate of captopril in skin tissues is considerably low when compared to intestinal tissues. All these factors make captopril an ideal drug candidate for transdermal delivery. In this research work an effort was made to formulate transdermal films of captopril by utilizing polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) as film formers and polyethylene glycol 400 (PEG400) as a plasticizer. Dimethyl sulfoxide (DMSO) and dimethylformamide (DMF) were used as permeation enhancers. Physicochemical parameters of the films such as appearance, thickness, weight variation and drug content were evaluated. The invitro permeation studies were carried out through excised human cadaver skin using Franz diffusion cells. The in-vitro permeation studies demonstrated that the film (P4) having the polymer ratio (PVP:PVA = 80:20) with DMSO (10%) resulted a promising drug release of 79.58% at 24 hours with a flux of 70.0 µg/cm(2)/hr. No signs of erythema or oedema were observed on the rabbit skin as a result of skin irritation study by Draize test. Based on the stability report it was confirmed that the films were physically and chemically stable, hence the prepared films are very well suited for transdermal application.
    Matched MeSH terms: Povidone/chemistry
  7. Akowuah GA, Zhari I
    Pharmazie, 2008 Nov;63(11):788-90.
    PMID: 19069237
    A simple high-performance liquid chromatography (HPLC) method to determine the content of betulinic acid (BA) in rat plasma collected at different times (0-8 h) after oral administration of Orthosiphon stamineus leaf extract was developed. The features of the assay include protein precipitation using acetonitrile and isocratic elution using reverse phase C-18 column with ultraviolet (UV) detection. The recovery of BA from plasma varied from 98.4 to 102.5%. The R.S.D of intra- and inter-day precision from rat plasma ranged from 4.2 to 9.8%. The maximum concentration of BA in the plasma was 1.2 +/- 0.3 microg/ml at 1 h after oral administration of the extract.
    Matched MeSH terms: Povidone/chemistry
  8. Lau CP, Abdul-Wahab MF, Jaafar J, Chan GF, Abdul Rashid NA
    J Microbiol Immunol Infect, 2017 Aug;50(4):427-434.
    PMID: 26427880 DOI: 10.1016/j.jmii.2015.08.004
    BACKGROUND/PURPOSE: Currently, silver nanoparticles (AgNPs) have gained importance in various industrial applications. However, their impact upon release into the environment on microorganisms remains unclear. The aim of this study was to analyze the effect of polyvinylpyrrolidone-capped AgNPs synthesized in this laboratory on two bacterial strains isolated from the environment, Gram-negative Citrobacter sp. A1 and Gram-positive Enterococcus sp. C1.

    METHODS: Polyvinylpyrrolidone-capped AgNPs were synthesized by ultrasound-assisted chemical reduction. Characterization of the AgNPs involved UV-visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy. Citrobacter sp. A1 and Enterococcus sp. C1 were exposed to varying concentrations of AgNPs, and cell viability was determined. Scanning electron microscopy was performed to evaluate the morphological alteration of both species upon exposure to AgNPs at 1000 mg/L.

    RESULTS: The synthesized AgNPs were spherical in shape, with an average particle size of 15 nm. The AgNPs had different but prominent effects on either Citrobacter sp. A1 or Enterococcus sp. C1. At an AgNP concentration of 1000 mg/L, Citrobacter sp. A1 retained viability for 6 hours, while Enterococcus sp. C1 retained viability only for 3 hours. Citrobacter sp. A1 appeared to be more resistant to AgNPs than Enterococcus sp. C1. The cell wall of both strains was found to be morphologically altered at that concentration.

    CONCLUSION: Minute and spherical AgNPs significantly affected the viability of the two bacterial strains selected from the environment. Enterococcus sp. C1 was more vulnerable to AgNPs, probably due to its cell wall architecture and the absence of silver resistance-related genes.

    Matched MeSH terms: Povidone/pharmacology*
  9. Noroozi M, Zakaria A, Radiman S, Abdul Wahab Z
    PLoS One, 2016;11(4):e0152699.
    PMID: 27064575 DOI: 10.1371/journal.pone.0152699
    In this paper, we report how few layers graphene that can be produced in large quantity with low defect ratio from exfoliation of graphite by using a high intensity probe sonication in water containing liquid hand soap and PVP. It was founded that the graphene powder obtained by this simple exfoliation method after the heat treatment had an excellent exfoliation into a single or layered graphene sheets. The UV-visible spectroscopy, FESEM, TEM, X-ray powder diffraction and Raman spectroscopy was used to analyse the graphene product. The thermal diffusivity of the samples was analysed using a highly accurate thermal-wave cavity photothermal technique. The data obtained showed excellent enhancement in the thermal diffusivity of the graphene dispersion. This well-dispersed graphene was then used to fabricate an electrically conductive polymer-graphene film composite. The results demonstrated that this low cost and environmental friendly technique allowed to the production of high quality layered graphene sheets, improved the thermal and electrical properties. This may find use in the wide range of applications based on graphene.
    Matched MeSH terms: Povidone/chemistry
  10. Lai NM, Lai NA, O'Riordan E, Chaiyakunapruk N, Taylor JE, Tan K
    Cochrane Database Syst Rev, 2016 Jul 13;7:CD010140.
    PMID: 27410189 DOI: 10.1002/14651858.CD010140.pub2
    BACKGROUND: The central venous catheter (CVC) is a device used for many functions, including monitoring haemodynamic indicators and administering intravenous medications, fluids, blood products and parenteral nutrition. However, as a foreign object, it is susceptible to colonisation by micro-organisms, which may lead to catheter-related blood stream infection (BSI) and in turn, increased mortality, morbidities and health care costs.

    OBJECTIVES: To assess the effects of skin antisepsis as part of CVC care for reducing catheter-related BSIs, catheter colonisation, and patient mortality and morbidities.

    SEARCH METHODS: In May 2016 we searched: The Cochrane Wounds Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations and Epub Ahead of Print); Ovid EMBASE and EBSCO CINAHL Plus. We also searched clinical trial registries for ongoing and unpublished studies. There were no restrictions with respect to language, date of publication or study setting.

    SELECTION CRITERIA: We included randomised controlled trials (RCTs) that assessed any type of skin antiseptic agent used either alone or in combination, compared with one or more other skin antiseptic agent(s), placebo or no skin antisepsis in patients with a CVC in place.

    DATA COLLECTION AND ANALYSIS: Two authors independently assessed the studies for their eligibility, extracted data and assessed risk of bias. We expressed our results in terms of risk ratio (RR), absolute risk reduction (ARR) and number need to treat for an additional beneficial outcome (NNTB) for dichotomous data, and mean difference (MD) for continuous data, with 95% confidence intervals (CIs).

    MAIN RESULTS: Thirteen studies were eligible for inclusion, but only 12 studies contributed data, with a total of 3446 CVCs assessed. The total number of participants enrolled was unclear as some studies did not provide such information. The participants were mainly adults admitted to intensive care units, haematology oncology units or general wards. Most studies assessed skin antisepsis prior to insertion and regularly thereafter during the in-dwelling period of the CVC, ranging from every 24 h to every 72 h. The methodological quality of the included studies was mixed due to wide variation in their risk of bias. Most trials did not adequately blind the participants or personnel, and four of the 12 studies had a high risk of bias for incomplete outcome data.Three studies compared different antisepsis regimens with no antisepsis. There was no clear evidence of a difference in all outcomes examined, including catheter-related BSI, septicaemia, catheter colonisation and number of patients who required systemic antibiotics for any of the three comparisons involving three different antisepsis regimens (aqueous povidone-iodine, aqueous chlorhexidine and alcohol compared with no skin antisepsis). However, there were great uncertainties in all estimates due to underpowered analyses and the overall very low quality of evidence presented.There were multiple head-to-head comparisons between different skin antiseptic agents, with different combinations of active substance and base solutions. The most frequent comparison was chlorhexidine solution versus povidone-iodine solution (any base). There was very low quality evidence (downgraded for risk of bias and imprecision) that chlorhexidine may reduce catheter-related BSI compared with povidone-iodine (RR of 0.64, 95% CI 0.41 to 0.99; ARR 2.30%, 95% CI 0.06 to 3.70%). This evidence came from four studies involving 1436 catheters. None of the individual subgroup comparisons of aqueous chlorhexidine versus aqueous povidone-iodine, alcoholic chlorhexidine versus aqueous povidone-iodine and alcoholic chlorhexidine versus alcoholic povidone-iodine showed clear differences for catheter-related BSI or mortality (and were generally underpowered). Mortality was only reported in a single study.There was very low quality evidence that skin antisepsis with chlorhexidine may also reduce catheter colonisation relative to povidone-iodine (RR of 0.68, 95% CI 0.56 to 0.84; ARR 8%, 95% CI 3% to 12%; ; five studies, 1533 catheters, downgraded for risk of bias, indirectness and inconsistency).Evaluations of other skin antiseptic agents were generally in single, small studies, many of which did not report the primary outcome of catheter-related BSI. Trials also poorly reported other outcomes, such as skin infections and adverse events.

    AUTHORS' CONCLUSIONS: It is not clear whether cleaning the skin around CVC insertion sites with antiseptic reduces catheter related blood stream infection compared with no skin cleansing. Skin cleansing with chlorhexidine solution may reduce rates of CRBSI and catheter colonisation compared with cleaning with povidone iodine. These results are based on very low quality evidence, which means the true effects may be very different. Moreover these results may be influenced by the nature of the antiseptic solution (i.e. aqueous or alcohol-based). Further RCTs are needed to assess the effectiveness and safety of different skin antisepsis regimens in CVC care; these should measure and report critical clinical outcomes such as sepsis, catheter-related BSI and mortality.

    Matched MeSH terms: Povidone-Iodine/therapeutic use
  11. Chan CK, Saw A, Kwan MK, Karina R
    J Orthop Surg (Hong Kong), 2009 Apr;17(1):19-22.
    PMID: 19398787
    To compare infection rates associated with 2 dressing solutions for metal-skin interfaces.
    Matched MeSH terms: Povidone-Iodine/therapeutic use*
  12. Mushahar L, Mei LW, Yusuf WS, Sivathasan S, Kamaruddin N, Idzham NJ
    Perit Dial Int, 2015 09 15;36(2):135-9.
    PMID: 26374836 DOI: 10.3747/pdi.2014.00195

    OBJECTIVE: Peritoneal dialysis (PD)-related infection is a common cause of catheter loss and the main reason for PD drop-out. Exit-site infection (ESI) is a pathway to developing tunnel infection and peritonitis, hence rigorous exit-site care has always been emphasized in PD therapy. The aim of this study was to evaluate the effect of exit-site dressing vs non-dressing on the rate of PD-related infection. ♦

    METHODS: A prospective randomized controlled study was conducted in prevalent PD patients at the Hospital Tuanku Jaafar Seremban, Negeri Sembilan, Malaysia, from April 2011 until April 2013. All patients were required to perform daily washing of the exit site with antibacterial soap during a shower. In the dressing group (n = 54), patients were required to clean their exit site using povidone-iodine after drying, followed by topical mupirocin antibiotic application to the exit site. The exit site was then covered with a sterile gauze dressing and the catheter immobilized with tape. In the non-dressing group (n = 54), patients were not required to do any further dressing after drying. They were only required to apply mupirocin cream to the exit site and then left the exit site uncovered. The catheter was immobilized with tape. The primary outcome was ESI. The secondary outcomes were evidence of tunnel infection or peritonitis. ♦

    RESULTS: A total of 97 patients completed the study. There were a total of 12 ESI episodes: 4 episodes in 4 patients in the dressing group vs 8 episodes in 4 patients in the non-dressing group. This corresponds to 1 episode per 241.3 patient-months vs 1 episode per 111.1 patient-months in the dressing and non-dressing groups respectively. Median time to first ESI episode was shorter in the non-dressing than in the dressing group, but not significant (p = 0.25). The incidence of gram-positive ESI in both groups was similar. There were no gram-negative ESI in the non-dressing group compared with 2 in the dressing group. The peritonitis rate was 1 per 37.1 patient-month in the dressing group and 1 per 44.4 patient-months in the non-dressing group. Median time to first peritonitis episode was significantly shorter in the dressing group compared to non-dressing (p = 0.03). There was no impact of dressing disruptions in the occurrence of major PD catheter-related infection. ♦

    CONCLUSION: Use of a non-dressing technique with only prophylactic topical mupirocin cream application is effective in preventing PD-related infection. The non-dressing technique is more cost-effective and convenient for PD patients, with fewer disposables.

    Matched MeSH terms: Povidone-Iodine/administration & dosage
  13. Gull N, Khan SM, Butt OM, Islam A, Shah A, Jabeen S, et al.
    Int J Biol Macromol, 2020 Nov 01;162:175-187.
    PMID: 32562726 DOI: 10.1016/j.ijbiomac.2020.06.133
    Inflammation is a key challenge in the treatment of chronic diseases. Spurred by topical advancement in polymer chemistry and drug delivery, hydrogels that release a drug in temporal, spatial and dosage controlled fashion have been trendy. This research focused on the fabrication of hydrogels with controlled drug release properties to control inflammation. Chitosan and polyvinyl pyrrolidone were used as base polymers and crosslinked with epichlorohydrin to form hydrogel films by solution casting technique. Prepared hydrogels were analyzed by swelling analysis in deionized water, buffer and electrolyte solutions and gel fraction. Functional groups confirmation and development of new covalent and hydrogen bonds, thermal stability (28.49%) and crystallinity were evaluated by FTIR, TGA and WAXRD, respectively. Rheological properties including gel strength and yield stress, elasticity (2309 MPa), porosity (75%) and hydrophilicity (73°) of prepared hydrogels were also evaluated. In vitro studies confirmed that prepared hydrogels have good biodegradability, excellent antimicrobial property and admirable cytotoxicity. Drug release profile (87.56% in 130 min) along with the drug encapsulation efficiency (84%) of prepared hydrogels was also studied. These results paved the path towards the development of hydrogels that can release the drugs with desired temporal patterns.
    Matched MeSH terms: Povidone/chemistry
  14. Kumar GP, Phani AR, Prasad RG, Sanganal JS, Manali N, Gupta R, et al.
    Int J Pharm, 2014 Aug 25;471(1-2):146-52.
    PMID: 24858388 DOI: 10.1016/j.ijpharm.2014.05.033
    Enrofloxacin is a fluoroquinolone derivative used for treating urinary tract, respiratory and skin infections in animals. However, low solubility and low bioavailability prevented it from using on humans. Polyvinylpyrrolidone (PVP) is an inert, non toxic polymer with excellent hydrophilic properties, besides it can enhance bioavailability by forming drug polymer conjugates. With the aim of increasing solubility and bioavailability, enrofloxacin thin films were prepared using PVP as a polymer matrix. The obtained oral thin films exhibited excellent uniformity and mechanical properties. Swelling properties of the oral thin films revealed that the water uptake was enhanced by 21%. The surface pH has been found to be 6.8±0.1 indicating that these films will not cause any irritation to oral mucosa. FTIR data of the oral thin films indicated physical interaction between drug and polymer. SEM analysis revealed uniform distribution of drug in polymer matrix. In vitro drug release profiles showed enhanced release profiles (which are also pH dependant) for thin films compared to pure drug. Antibacterial activity was found to be dose dependent and maximum susceptibility was found on Klebsiella pneumonia making this preparation more suitable for respiratory infections.
    Matched MeSH terms: Povidone/chemistry*
  15. Shah SM, Ullah F, Khan S, Shah SM, de Matas M, Hussain Z, et al.
    Drug Des Devel Ther, 2016;10:3837-3850.
    PMID: 27920499
    Artemether (ARTM) is a very effective antimalarial drug with poor solubility and consequently low bioavailability. Smart nanocrystals of ARTM with particle size of 161±1.5 nm and polydispersity index of 0.172±0.01 were produced in <1 hour using a wet milling technology, Dena(®) DM-100. The crystallinity of the processed ARTM was confirmed using differential scanning calorimetry and powder X-ray diffraction. The saturation solubility of the ARTM nanocrystals was substantially increased to 900 µg/mL compared to the raw ARTM in water (145.0±2.3 µg/mL) and stabilizer solution (300.0±2.0 µg/mL). The physical stability studies conducted for 90 days demonstrated that nanocrystals stored at 2°C-8°C and 25°C were very stable compared to the samples stored at 40°C. The nanocrystals were also shown to be stable when processed at acidic pH (2.0). The solubility and dissolution rate of ARTM nanocrystals were significantly increased (P<0.05) compared to those of its bulk powder form. The results of in vitro studies showed significant antimalarial effect (P<0.05) against Plasmodium falciparum and Plasmodium vivax. The IC50 (median lethal oral dose) value of ARTM nanocrystals was 28- and 54-fold lower than the IC50 value of unprocessed drug and 13- and 21-fold lower than the IC50 value of the marketed tablets, respectively. In addition, ARTM nanocrystals at the same dose (2 mg/kg) showed significantly (P<0.05) higher reduction in percent parasitemia (89%) against P. vivax compared to the unprocessed (27%), marketed tablets (45%), and microsuspension (60%). The acute toxicity study demonstrated that the LD50 value of ARTM nanocrystals is between 1,500 mg/kg and 2,000 mg/kg when given orally. This study demonstrated that the wet milling technology (Dena(®) DM-100) can produce smart nanocrystals of ARTM with enhanced antimalarial activities.
    Matched MeSH terms: Povidone/chemistry
  16. Ahmed S, Govender T, Khan I, Rehman NU, Ali W, Shah SMH, et al.
    Drug Des Devel Ther, 2018;12:255-269.
    PMID: 29440875 DOI: 10.2147/DDDT.S148912
    Background and aim: The challenges with current antimicrobial drug therapy and resistance remain a significant global health threat. Nanodrug delivery systems are playing a crucial role in overcoming these challenges and open new avenues for effective antimicrobial therapy. While fluticasone (FLU), a poorly water-soluble corticosteroid, has been reported to have potential antimicrobial activity, approaches to optimize its dissolution profile and antimicrobial activity are lacking in the literature. This study aimed to combine an experimental study with molecular modeling to design stable FLU nanopolymeric particles with enhanced dissolution rates and antimicrobial activity.

    Methods: Six different polymers were used to prepare FLU nanopolymeric particles: hydroxyl propyl methylcellulose (HPMC), poly (vinylpyrrolidone) (PVP), poly (vinyl alcohol) (PVA), ethyl cellulose (EC), Eudragit (EUD), and Pluronics®. A low-energy method, nanoprecipitation, was used to prepare the polymeric nanoparticles.

    Results and conclusion: The combination of HPMC-PVP and EUD-PVP was found most effective to produce stable FLU nanoparticles, with particle sizes of 250 nm ±2.0 and 280 nm ±4.2 and polydispersity indices of 0.15 nm ±0.01 and 0.25 nm ±0.03, respectively. The molecular modeling studies endorsed the same results, showing highest polymer drug binding free energies for HPMC-PVP-FLU (-35.22 kcal/mol ±0.79) and EUD-PVP-FLU (-25.17 kcal/mol ±1.12). In addition, it was observed that Ethocel® favored a wrapping mechanism around the drug molecules rather than a linear conformation that was witnessed for other individual polymers. The stability studies conducted for 90 days demonstrated that HPMC-PVP-FLU nanoparticles stored at 2°C-8°C and 25°C were more stable. Crystallinity of the processed FLU nanoparticles was confirmed using differential scanning calorimetry, powder X-ray diffraction analysis and TEM. The Fourier transform infrared spectroscopy (FTIR) studies showed that there was no chemical interaction between the drug and chosen polymer system. The HPMC-PVP-FLU nanoparticles also showed enhanced dissolution rate (P<0.05) compared to the unprocessed counterpart. The in vitro antibacterial studies showed that HPMC-PVP-FLU nanoparticles displayed superior effect against gram-positive bacteria compared to the unprocessed FLU and positive control.

    Matched MeSH terms: Povidone/chemistry
  17. Tan YT, Heng PW, Wan LS
    Pharm Dev Technol, 1999;4(4):561-70.
    PMID: 10578511
    Modified-release drug spheroids coated with an aqueous mixture of high-viscosity hydroxypropylmethylcellulose (HPMC) and sodium carboxymethylcellulose (NaCMC) were formulated. The preparation of core drug spheroids and the coating procedures were performed using the rotary processor and a bottom-spray fluidized bed, respectively. Dissolution studies indicated that incorporation of suitable additives, such as poly(vinylpyrrolidone) (PVP) and poly(ethylene glycol) 400 (PEG) improved the flexibility and integrity of the coat layer by retarding the drug release. An increase in coating levels applied generally retarded the release rate of the drug. However, the ratio of HPMC to NaCMC in the mixed, plasticized polymeric coat played a more dominant role in determining the dissolution T50% values. The optimal ratio of HPMC to NaCMC for prolonged drug release was found to be 3:1, whereas an increase in the amount of NaCMC in the mixed polymer coat only increased drug release. The synergistic viscosity effect of HPMC and NaCMC in retarding drug release rate was greater in distilled water than in dissolution media of pH 1 and 7.2. Cross-sectional view of the scanning electron micrograph showed that all of the coated spheroids exhibited a well-fused, continuous, and distinct layer of coating film. The drug release kinetics followed a biexponential first-order kinetic model.
    Matched MeSH terms: Povidone
  18. Pagthinathan, M., Ghazali, H.M., Yazid, A.M., Foo, H.L.
    MyJurnal
    Extracts from ‘kesinai’ (Streblus asper) leaves were investigated as a potential source of enzymes that can serve as an alternative to calf rennet in cheese making. Different types of extraction buffers were investigated namely sodium acetate buffer (pH 4.2-5.0), phosphate buffer (pH 6.0-7.0) and Tris-HCl buffer (pH 7.0-9.0). Finally, the milk-clotting enzyme was extracted using 100 mM Tris-HCl buffer (pH 7.4) with and without 5.0 mg/mL polyvinylpyrrolidone, 0.015 mL/mL Triton X-100 and 2 mM sodium metabisulphite. Purification was carried out using acetone precipitation, and ion-exchange and size-exclusion chromatographic techniques. Results showed that 100 mM Tris-HCl buffer (pH 7.4) was the most efficient extraction buffer among the buffers used in the extraction study. After the final purification step of size-exclusion chromatography, the enzyme was purified 3.3-fold with 42.3% of recovery. The enzyme showed an optimum temperature and pH at 60°C and pH 7.4, respectively. The enzyme was stable up to 70°C for one hour and the partially purified enzyme retained 83% and 96% of its original activity at pH 6.0 and 8.0, respectively. The molecular weight of the partially enzyme was estimated to be 75.8 kDa on SDS-PAGE. The milk-clotting activity of ‘kesinai’ enzyme was found to be lower than that of commercial Mucor rennet.
    Matched MeSH terms: Povidone
  19. Abba MU, Man HC, Azis RS, Isma Idris A, Hazwan Hamzah M, Yunos KF, et al.
    Nanomaterials (Basel), 2021 Feb 04;11(2).
    PMID: 33557323 DOI: 10.3390/nano11020399
    High proportion of copper has become a global challenge owing to its negative impact on the environment and public health complications. The present study focuses on the fabrication of a polyvinylidene fluoride (PVDF)-polyvinyl pyrrolidone (PVP) fiber membrane incorporated with varying loading (0, 0.5, 1.0, 1.5, and 2.0 wt%) of titanium dioxide (TiO2) nanoparticles via phase inversion technique to achieve hydrophilicity along with high selectivity for copper removal. The developed fibers were characterized based on scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), permeability, porosity, zeta potential, and contact angle. The improved membrane (with 1.0 wt% TiO2) concentration recorded the maximum flux (223 L/m2·h) and copper rejection (98.18%). Similarly, 1.0 wt% concentration of TiO2 nanoparticles made the membrane matrix more hydrophilic with the least contact angle of 50.01°. The maximum copper adsorption capacity of 69.68 mg/g was attained at 1.0 wt% TiO2 concentration. The experimental data of adsorption capacity were best fitted to the Freundlich isotherm model with R2 value of 0.99573. The hybrid membrane developed in this study has considerably eliminated copper from leachate and the concentration of copper in the permeate was substantially reduced to 0.044 mg/L, which is below standard discharge threshold.
    Matched MeSH terms: Povidone
  20. Al-Japairai KAS, Alkhalidi HM, Mahmood S, Almurisi SH, Doolaanea AA, Al-Sindi TA, et al.
    ACS Omega, 2020 Dec 22;5(50):32466-32480.
    PMID: 33376884 DOI: 10.1021/acsomega.0c04588
    Telmisartan suffers from low oral bioavailability due to its poor water solubility. The research work presents a formulation of solid dispersed (SD) telmisartan formulation as a ternary mixture of a drug, a polymeric carrier (poly(vinylpyrrolidone) (PVP) K30), and an alkalizer (Na2CO3). The preparation method, which was lyophilization of an aqueous solution containing the ingredients, was free from any organic solvent. The developed SD formulations resulted in a significant improvement in in vitro dissolution (>90% drug dissolution in 15 min) compared to pure telmisartan. Solid-state characterization by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) studies indicated the conversion of crystalline telmisartan into an amorphous form. Fourier transform infrared (FTIR) spectroscopy revealed the drug-polymer interaction that was responsible for reducing the chances of recrystallization. A short-term stability study showed that selected SD formulations were stable in terms of in vitro dissolution and retained their amorphous structure in ambient and accelerated conditions over 2 months. Selected formulations (drug/PVP K30/Na2CO3 as 1:1:2 or 1:2:2 weight ratio) resulted in >2.48 times relative oral bioavailability compared to marketed formulations. It was considered that the incorporation of an alkalizer and a hydrophilic polymer, and amorphization of telmisartan by lyophilization, could enhance in vitro dissolution and improve oral bioavailability.
    Matched MeSH terms: Povidone
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