Displaying publications 141 - 160 of 161 in total

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  1. Gelatine enhances drug dispersion in alginate bilayer film via the formation of crystalline microaggregates
    Thu HE, Ng SF
    Int J Pharm, 2013 Sep 15;454(1):99-106.
    PMID: 23856162 DOI: 10.1016/j.ijpharm.2013.06.082
    In our previous study, a novel alginate-based bilayer film for slow-release wound dressings was successfully developed. We found that alginate alone yielded poor films; however, the addition of gelatine had significantly enhanced the drug dispersion as well as the physical properties. Here, an investigation of the drug-polymer interactions in the bilayer films was carried out. Drug content uniformity test and microscopy observation revealed that the addition of gelatine generated bilayer films with a homogenous drug distribution within the matrix. The FTIR and XRD data showed an increase in film crystallinity which might infer the presence of drug-polymer crystalline microaggregates in the films. DSC confirmed the drug-polymer interaction and indicated that the gelatine has no effect on the thermal behaviour of the microaggregates, suggesting the compatibility of the drug and excipients in the bilayer films. In conclusion, the addition of gelatine can promote homogenous dispersion of hydrophobic drugs in alginate films possibly through the formation of crystalline microaggregates.
    Matched MeSH terms: Calorimetry, Differential Scanning
  2. Rheological behavior of biodegradable N-succinyl chitosan-g-poly (acrylic acid) hydrogels and their applications as drug carrier and in vitro theophylline release
    Bashir S, Teo YY, Ramesh S, Ramesh K, Mushtaq MW
    Int J Biol Macromol, 2018 Oct 01;117:454-466.
    PMID: 29807081 DOI: 10.1016/j.ijbiomac.2018.05.182
    Novel pH sensitive N-succinyl chitosan-g-poly (acrylic acid) hydrogels were synthesized through free radical mechanism. Rheometer was used to observe the mechanical strength of the hydrogels. In vitro degradation was conducted in SIF (pH 7.4). The effect of concentration of monomers, initiator, and crosslinking agent and pH and ionic strength of NaCl, CaCl2, and AlCl3 on swelling of the hydrogels was observed. The results showed that equilibrium swelling ratio was highly influenced by concentration of monomers, initiator, and crosslinking agent concentration, and pH and salt solutions of NaCl, CaCl2, and AlCl3. The swelling kinetics revealed that swelling followed non-Fickian anomalous transport. Furthermore, theophylline loading (DL %) and encapsulation efficiency (EE %) of the hydrogels was in the range of 15.5 ± 0.15-22.8 ± 0.06% and 62 ± 0.15-91 ± 0.26%, respectively. The release of theophylline in physiological mediums was strongly influenced by the pH. The theophylline release was in the range of 51 ± 0.20-92 ± 0.12% in SIF and 7.4 ± 0.02-14.9 ± 0.03% in SGF (pH 1.2), respectively. The release data fitted well to Korsmeyer-Peppas model. The chemical activity of the theophylline suggested that drug maintained its chemical activity after release in vitro. The results suggest that synthesized hydrogels are excellent drug carriers.
    Matched MeSH terms: Calorimetry, Differential Scanning
  3. In Vitro Investigation of Influences of Chitosan Nanoparticles on Fluorescein Permeation into Alveolar Macrophages
    Chachuli SH, Nawaz A, Shah K, Naharudin I, Wong TW
    Pharm Res, 2016 06;33(6):1497-508.
    PMID: 26951565 DOI: 10.1007/s11095-016-1893-5
    PURPOSE: Pulmonary infection namely tuberculosis is characterized by alveolar macrophages harboring a large microbe population. The chitosan nanoparticles exhibit fast extracellular drug release in aqueous biological milieu. This study investigated the matrix effects of chitosan nanoparticles on extracellular drug diffusion into macrophages.

    METHODS: Oligo, low, medium and high molecular weight chitosan nanoparticles were prepared by nanospray drying technique. These nanoparticles were incubated with alveolar macrophages in vitro and had model drug sodium fluorescein added into the same cell culture. The diffusion characteristics of sodium fluorescein and nanoparticle behavior were investigated using fluorescence microscopy, scanning electron microscopy, differential scanning calorimetry and Fourier transform infrared spectroscopy techniques.

    RESULTS: The oligochitosan nanoparticles enabled macrophage membrane fluidization with the extent of sodium fluorescein entry into macrophages being directly governed by the nanoparticle loading. Using nanoparticles made of higher molecular weight chitosan, sodium fluorescein permeation into macrophages was delayed due to viscous chitosan diffusion barrier at membrane boundary.

    CONCLUSION: Macrophage-chitosan nanoparticle interaction at membrane interface dictates drug migration into cellular domains.

    Matched MeSH terms: Calorimetry, Differential Scanning
  4. Development of mushroom polysaccharide and probiotics based solid self-nanoemulsifying drug delivery system loaded with curcumin and quercetin to improve their dissolution rate and permeability: State of the art
    Khursheed R, Singh SK, Wadhwa S, Gulati M, Kapoor B, Jain SK, et al.
    Int J Biol Macromol, 2021 Oct 31;189:744-757.
    PMID: 34464640 DOI: 10.1016/j.ijbiomac.2021.08.170
    The role of mushroom polysaccharides and probiotics as pharmaceutical excipients for development of nanocarriers has never been explored. In the present study an attempt has been made to explore Ganoderma lucidum extract powder (GLEP) containing polysaccharides and probiotics to convert liquid self nanoemulsifying drug delivery system (SNEDDS) into solid free flowing powder. Two lipophilic drugs, curcumin and quercetin were used in this study due to their dissolution rate limited oral bioavailability and poor permeability. These were loaded into liquid SNEDDS by dissolving them into isotropic mixture of Labrafill M1944CS, Capmul MCM, Tween-80 and Transcutol P. The liquid SNEDDS were solidified using probiotics and mushroom polysaccharides as carriers and Aerosil-200 as coating agent. The solidification was carried out using spray drying process. The process and formulation variables for spray drying process of liquid SNEDDS were optimized using Box Behnken Design to attain required powder properties. The release of both drugs from the optimized spray dried (SD) formulation was found to be more than 90%, whereas, it was less than 20% for unprocessed drugs. The results of DSC, PXRD and SEM, showed that the developed L-SNEDDS preconcentrate was successfully loaded onto the porous surface of probiotics, mushroom polysaccharides and Aerosil-200.
    Matched MeSH terms: Calorimetry, Differential Scanning
  5. A stable hydrocortisone nanosuspension for improved dissolution: Preparation, characterization and in vitro evaluation
    Ali HS, Khan S, York P, Shah SM, Khan J, Hussain Z, et al.
    Pak J Pharm Sci, 2017 Sep;30(5):1635-1643.
    PMID: 29084684
    Drug nanosuspensions have gained tremendous attraction as a platform in drug delivery. In the present work, a nanosuspension was prepared by a wet milling approach in order to increase saturation solubility and dissolution of the water insoluble drug, hydrocortisone. Size of the generated particeles was 290 nm ± 9 nm having a zeta potential of -1.9 mV ± 0.6 mV. Nanosized particles were found to have a rod shape with a narrow particle size distribution (PDI =0.17). Results of differential scanning calorimetry and X-ray diffraction analyses revealed minor modifications of crystallinity of hydrocortisone following the milling process. Solubility of hydrocortisone was enhanced by nanonization to 875µg/ml ±2.5, an almost 2.9-fold compared to the raw hydrocortisone. Moreover, the nanosuspension formulation substabtially enhanced the dissolution rate of hydrocortisone where >97% of the hydrocortisone was dissolved within 10 minutes opposed to 22.3% for the raw 50% for the raw hydrocortisone and the commercial tablet, respectively. The bioavailability study resulted in AUC 0-9h for HC nanosuspensions (31.50±2.50), which is significantly (p<0.05) higher compared to the AUC 0-9h (14.85±3.25) resulted for HC solution. The nanosuspension was physically stable at room temperature for 24 months.
    Matched MeSH terms: Calorimetry, Differential Scanning
  6. Domperidone nanocrystals with boosted oral bioavailability: fabrication, evaluation and molecular insight into the polymer-domperidone nanocrystal interaction
    Ndlovu ST, Ullah N, Khan S, Ramharack P, Soliman M, de Matas M, et al.
    Drug Deliv Transl Res, 2019 Feb;9(1):284-297.
    PMID: 30387048 DOI: 10.1007/s13346-018-00596-w
    The aim of this study was to employ experimental and molecular modelling approaches to use molecular level interactions to rationalise the selection of suitable polymers for use in the production of stable domperidone (DOMP) nanocrystals with enhanced bioavailability. A low-energy antisolvent precipitation method was used for the preparation and screening of polymers for stable nanocrystals of DOMP. Ethyl cellulose was found to be very efficient in producing stable DOMP nanocrystals with particle size of 130 ± 3 nm. Moreover, the combination of hydroxypropyl methylcellulose and polyvinyl alcohol was also shown to be better in producing DOMP nanocrystals with smaller particle size (200 ± 3.5 nm). DOMP nanosuspension stored at 2-8 °C and at room temperature (25 °C) exhibited better stability compared to the samples stored at 40 °C. Crystallinity of the unprocessed and processed DOMP was monitored by differential scanning calorimetry and powder X-ray diffraction. DOMP nanocrystals gave enhanced dissolution rate compared to the unprocessed drug substance. DOMP nanocrystals at a dose of 10 mg/kg in rats showed enhanced bioavailability compared to the raw drug substance and marketed formulation. A significant increase in plasma concentration of 2.6 μg/mL with a significant decrease in time (1 h) to reach maximum plasma concentration was observed for DOMP nanocrystals compared to the raw DOMP. Molecular modelling studies provided underpinning knowledge at the molecular level of the DOMP-polymer nanocrystal interactions and substantiated the experimental studies. This included an understanding of the impact of polymers on the size of nanocrystals and their associated stability characteristics.
    Matched MeSH terms: Calorimetry, Differential Scanning
  7. Chitosan coated alginate-xanthan gum bead enhanced pH and thermotolerance of Lactobacillus plantarum LAB12
    Fareez IM, Lim SM, Mishra RK, Ramasamy K
    Int J Biol Macromol, 2015 Jan;72:1419-28.
    PMID: 25450046 DOI: 10.1016/j.ijbiomac.2014.10.054
    The vulnerability of probiotics at low pH and high temperature has limited their optimal use as nutraceuticals. This study addressed these issues by adopting a physicochemical driven approach of incorporating Lactobacillus plantarum LAB12 into chitosan (Ch) coated alginate-xanthan gum (Alg-XG) beads. Characterisation of Alg-XG-Ch, which elicited little effect on bead size and polydispersity, demonstrated good miscibility with improved bead surface smoothness and L. plantarum LAB12 entrapment when compared to Alg, Alg-Ch and Alg-XG. Sequential incubation of Alg-XG-Ch in simulated gastric juice and intestinal fluid yielded high survival rate of L. plantarum LAB12 (95%) at pH 1.8 which in turn facilitated sufficient release of probiotics (>7 log CFU/g) at pH 6.8 in both time- and pH-dependent manner. Whilst minimising viability loss at 75 and 90 °C, Alg-XG-Ch improved storage durability of L. plantarum LAB12 at 4 °C. The present results implied the possible use of L. plantarum LAB12 incorporated in Alg-XG-Ch as new functional food ingredient with health claims.
    Matched MeSH terms: Calorimetry, Differential Scanning
  8. Biomimetic growth of bone-like apatite via simulated body fluid on hydroxyethyl cellulose/polyvinyl alcohol electrospun nanofibers
    Chahal S, Chalal S, Fathima SJ, Yusoff MB
    Biomed Mater Eng, 2014;24(1):799-806.
    PMID: 24211966 DOI: 10.3233/BME-130871
    In this study, randomly oriented hydroxyethyl cellulose/polyvinyl alcohol (HEC/PVA) nanofibers were fabricated by electrospinning. The blend solutions of HEC/PVA with different weight ratio of HEC to PVA were prepared using water as solvent to fabricate nanofibers. These nanofibrous scaffolds were coated with bone-like apatite by immersing into 10x simulated body fluid (SBF) for different time periods. The morphology and structure of the nanofibers were characterized by SEM, FTIR and DSC. FESEM-EDS and FTIR analysis were used to confirm the deposition of apatite on the surface of nanofibers. The results of this study suggest that this apatite coated nanofibrous scaffolds could be a suitable biomaterial for bone tissue engineering.
    Matched MeSH terms: Calorimetry, Differential Scanning
  9. Optimization of hexametaphosphate-assisted extraction and functional characterization of palm kernel cake protein
    Chee KL, Ayob MK
    Food Sci Technol Int, 2013 Apr;19(2):109-22.
    PMID: 23520324 DOI: 10.1177/1082013212442185
    Response surface methodology was applied to study the optimization of palm kernel cake protein (PKCP) hexametaphosphate-assisted extraction. The optimum PKCP yield (28.37%) when extracted using 1.50% sodium hexametaphosphate (SHMP) of pH 10, at 50 °C, and the 1:70 (w/v) ratio of cake-to-solvent was significantly (P 
    Matched MeSH terms: Calorimetry, Differential Scanning
  10. Characterization of hydroxypropylmethylcellulose films using microwave non-destructive testing technique
    Anuar NK, Wui WT, Ghodgaonkar DK, Taib MN
    J Pharm Biomed Anal, 2007 Jan 17;43(2):549-57.
    PMID: 16978823
    The applicability of microwave non-destructive testing (NDT) technique in characterization of matrix property of pharmaceutical films was investigated. Hydroxypropylmethylcellulose and loratadine were selected as model matrix polymer and drug, respectively. Both blank and drug loaded hydroxypropylmethylcellulose films were prepared using the solvent-evaporation method and were conditioned at the relative humidity of 25, 50 and 75% prior to physicochemical characterization using microwave NDT technique as well as ultraviolet spectrophotometry, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) techniques. The results indicated that blank hydroxypropylmethylcellulose film exhibited a greater propensity of polymer-polymer interaction at the O-H and C-H domains of the polymer chains upon conditioned at a lower level of relative humidity. In the case of loratadine loaded films, a greater propensity of polymer-polymer and/or drug-polymer interaction via the O-H moiety was mediated in samples conditioned at the lower level of relative humidity, and via the C-H moiety when 50% relative humidity was selected as the condition for sample storage. Apparently, the absorption and transmission characteristics of both blank and drug loaded films for microwave varied with the state of polymer-polymer and/or drug-polymer interaction involving the O-H and C-H moieties. The measurement of microwave NDT test at 8GHz was sensitive to the chemical environment involving O-H moiety while it was greatly governed by the C-H moiety in test conducted at a higher frequency band of microwave. Similar observation was obtained with respect to the profiles of microwave NDT measurements against the state of polymer-polymer and/or drug-polymer interaction of hydroxypropylmethylcellulose films containing chlorpheniramine maleate. The microwave NDT measurement is potentially suitable for use as an apparent indicator of the state of polymer-polymer and drug-polymer interaction of the matrix.
    Matched MeSH terms: Calorimetry, Differential Scanning
  11. Fabrication of composite poly(d,l-lactide)/montmorillonite nanoparticles for controlled delivery of acetaminophen by solvent-displacement method using glass capillary microfluidics
    Othman R, Vladisavljević GT, Thomas NL, Nagy ZK
    Colloids Surf B Biointerfaces, 2016 May 01;141:187-195.
    PMID: 26852102 DOI: 10.1016/j.colsurfb.2016.01.042
    Paracetamol (PCM)-loaded composite nanoparticles (NPs) composed of a biodegradable poly(d,l-lactide) (PLA) polymer matrix filled with organically modified montmorillonite (MMT) nanoparticles were fabricated by antisolvent nanoprecipitation in a microfluidic co-flow glass capillary device. The incorporation of MMT in the polymer improved both the drug encapsulation efficiency and the drug loading, and extended the rate of drug release in simulated intestinal fluid (pH 7.4). The particle size increased on increasing both the drug loading and the concentration of MMT in the polymer matrix, and decreased on increasing the aqueous to organic flow rate ratio. The drug encapsulation efficiency in the NPs was higher at higher aqueous to organic flow rate ratio due to faster formation of the NPs. The PCM-loaded PLA NPs containing 2 wt% MMT in PLA prepared at an aqueous to organic flow rate ratio of 10 with an orifice size of 200 μm exhibited a spherical shape with a mean size of 296 nm, a drug encapsulation efficiency of 38.5% and a drug loading of 5.4%. The encapsulation of MMT and PCM in the NPs was confirmed by transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis and attenuated total reflection-Fourier transform infrared spectroscopy.
    Matched MeSH terms: Calorimetry, Differential Scanning
  12. Fulltext Formulation, Characterization and Biological Activity Screening of Sodium Alginate-Gum Arabic Nanoparticles Loaded with Curcumin
    Hassani A, Mahmood S, Enezei HH, Hussain SA, Hamad HA, Aldoghachi AF, et al.
    Molecules, 2020 May 10;25(9).
    PMID: 32397633 DOI: 10.3390/molecules25092244
    The approach of drug delivery systems emphasizes the use of nanoparticles as a vehicle, offering the optional property of delivering drugs as a single dose rather than in multiple doses. The current study aims to improve antioxidant and drug release properties of curcumin loaded gum Arabic-sodium alginate nanoparticles (Cur/ALG-GANPs). The Cur/ALG-GANPs were prepared using the ionotropic gelation technique and further subjected to physico-chemical characterization using attenuated total reflectance-Fourier transform infrared (ATR-FTIR), X-ray diffractometry (XRD), differential scanning calorimetry (DSC), size distribution, and transmission electron microscopy (TEM). The size of Cur/ALG-GANPs ranged between 10 ± 0.3 nm and 190 ± 0.1 nm and the zeta potential was -15 ± 0.2 mV. The antioxidant study of Cur/ALG-GANPs exhibited effective radical scavenging capacity for 1,1-diphenyl-2-picrylhydrazyl (DPPH) at concentrations that ranged between 30 and 500µg/mL. Cytotoxicity was performed using MTT assay to measure their potential in inhibiting the cell growth and the result demonstrated a significant anticancer activity of Cur/ALG-GANPs against human liver cancer cells (HepG2) than in colon cancer (HT29), lung cancer (A549) and breast cancer (MCF7) cells. Thus, this study indicates that Cur/ALG-GANPs have promising anticancer properties that might aid in future cancer therapy.
    Matched MeSH terms: Calorimetry, Differential Scanning
  13. Nose-to-brain delivery of teriflunomide-loaded lipid-based carbopol-gellan gum nanogel for glioma: Pharmacological and in vitro cytotoxicity studies
    Gadhave D, Rasal N, Sonawane R, Sekar M, Kokare C
    Int J Biol Macromol, 2021 Jan 15;167:906-920.
    PMID: 33186648 DOI: 10.1016/j.ijbiomac.2020.11.047
    The research work was intended to formulate teriflunomide (TFM) loaded nano lipid-based (TNLC) carbopol-gellan gum in situ gel (TNLCGHG) and to investigate its therapeutic efficacy against glioma, a brain and spine tumor. Nanoformulation was developed using gellan gum and carbopol 974P as gelling and mucoadhesive agents, respectively, Glyceryl di-behenate and Glyceryl mono-linoleate blend as lipids, and Gelucire 44/14: water blend as surfactant system. Globule size, PDI, zeta potential, encapsulation efficiency, mucoadhesive strength, and nasal permeation were found to be 117.80 nm, 0.56, -21.86 mV, 81.16%, 4.80 g, and 904 μg/cm2, respectively. Anticancer efficacy of TFM-loaded nano lipid-based carbopol-gellan gum in situ gel (TNLCGHG) was determined in human U-87MG glioma cell line. IC50 was found 7.0 μg/mL for TNLCGHG, 4.8 μg/mL for pure TFM, and 78.5 μg/mL for TNLC, which approve the superiority of surfactant along with gellan gum as permeation enhancer. Brain Cmax for technetium (99mTC) labeled intranasal (i.n.) 99mTC-TNLCGHG was found 2-folds higher than 99mTC-TNLC (i.n.) and 99mTC-TNLC intravenous (i.v.) because the TNLCGHG formulation contains surfactant with natural gelling polymers, which promisingly improved drug permeability. Finally, this research revealed encouraging outcomes and successfully developed intranasal TNLCGHG nanoformulation as a novel tool for safe delivery of TFM in glioma patients.
    Matched MeSH terms: Calorimetry, Differential Scanning
  14. Stomach-site specific drug delivery system of clarithromycin for eradication of Helicobacter pylori
    Rajinikanth PS, Mishra B
    Chem Pharm Bull (Tokyo), 2009 Oct;57(10):1068-75.
    PMID: 19801860
    Gellan gum based floating beads containing clarithromycin (FBC) were prepared by iontotropic gelation method for stomach-specific drug delivery against Helicobacter pylori. The scanning electron microscope photograph indicated that prepared beads were spherical in shape with rough outer surface. Formulation variables such as concentrations of gellan, calcium carbonate and drug loading influenced the in vitro drug release characteristics of prepared beads. In vitro release rate of clarithromycin was corrected using first order degradation rate constant which is degraded significantly during the release study in simulated gastric fluid pH 2.0. Further, the absence of interactions between drug and polymer was confirmed by differential scanning calorimetry analysis. Kinetic treatment of the in vitro drug release data with different kinetic equations revealed matrix diffusion mechanism. Prepared beads showed good anti-microbial activity against isolated H. pylori strain. The prepared beads have shown good in vivo floating efficiency in rabbit stomach. The stability studies of beads did not show any significant changes after storage of beads at 40 degrees C/75% relative humidity for 6 months. The preliminary results from this study suggest that floating beads of gellan can be used to incorporate antibiotics like clarithromycin and may be effective when administered locally in the stomach against H. pylori.
    Matched MeSH terms: Calorimetry, Differential Scanning
  15. Polyvinylpyrrolidone oral films of enrofloxacin: film characterization and drug release
    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: Calorimetry, Differential Scanning
  16. Fulltext A/T Run Geometry of B-form DNA Is Independent of Bound Methyl-CpG Binding Domain, Cytosine Methylation and Flanking Sequence
    Chia JY, Tan WS, Ng CL, Hu NJ, Foo HL, Ho KL
    Sci Rep, 2016 08 09;6:31210.
    PMID: 27502833 DOI: 10.1038/srep31210
    DNA methylation in a CpG context can be recognised by methyl-CpG binding protein 2 (MeCP2) via its methyl-CpG binding domain (MBD). An A/T run next to a methyl-CpG maximises the binding of MeCP2 to the methylated DNA. The A/T run characteristics are reported here with an X-ray structure of MBD A140V in complex with methylated DNA. The A/T run geometry was found to be strongly stabilised by a string of conserved water molecules regardless of its flanking nucleotide sequences, DNA methylation and bound MBD. New water molecules were found to stabilise the Rett syndrome-related E137, whose carboxylate group is salt bridged to R133. A structural comparison showed no difference between the wild type and MBD A140V. However, differential scanning calorimetry showed that the melting temperature of A140V constructs in complex with methylated DNA was reduced by ~7 °C, although circular dichroism showed no changes in the secondary structure content for A140V. A band shift analysis demonstrated that the larger fragment of MeCP2 (A140V) containing the transcriptional repression domain (TRD) destabilises the DNA binding. These results suggest that the solution structure of MBD A140V may differ from the wild-type MBD although no changes in the biochemical properties of X-ray A140V were observed.
    Matched MeSH terms: Calorimetry, Differential Scanning
  17. Thermal sintering: a novel technique used in the design, optimization and biopharmaceutical evaluation of propranolol HCl gastric floating tablets
    Venkata Srikanth M, Songa AS, Nali SR, Battu JR, Kolapalli VR
    Drug Dev Ind Pharm, 2014 Jan;40(1):33-45.
    PMID: 23317339 DOI: 10.3109/03639045.2012.744416
    The objective of the present investigation was to study the applicability of thermal sintering technique for the development of gastric floating tablets of propranolol HCl. Formulations were prepared using four independent variables, namely (i) polymer quantity, (ii) sodium bicarbonate concentration, (iii) sintering temperature and (iv) sintering time. Floating lag time and t95 were taken as dependent variables. Tablets were prepared by the direct compression method and were evaluated for physicochemical properties, in vitro buoyancy and dissolution studies. From the drug release studies, it was observed that drug retarding property mainly depends upon the sintering temperature and time of exposure. The statistically optimized formulation (PTSso) was characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry studies, and no significant chemical interaction between drug and polymer was observed. Optimized formulation was stable at accelerated conditions for a period of six months. PTSso was evaluated for in vivo buoyancy studies in humans for both fed and fasted states and found that gastric residence time of the floating tablets were enhanced by fed stage but not in fasted state. Optimized formulation PTSso and commercial formulation Ciplar LA 80 were subjected to bioavailability studies in healthy human volunteers by estimating pharmacokinetic parameters such as Cmax, Tmax, area under curve (AUC), elimination rate constant (Kel), biological half-life (t1/2) and mean residence time (MRT). There was a significant increase in the bioavailability of the propranolol HCl from PTSso formulation, which was evident from increased AUC levels and larger MRT values than Ciplar LA 80.
    Matched MeSH terms: Calorimetry, Differential Scanning
  18. Fulltext Berberine nanoparticles with enhanced in vitro bioavailability: characterization and antimicrobial activity
    Sahibzada MUK, Sadiq A, Faidah HS, Khurram M, Amin MU, Haseeb A, et al.
    Drug Des Devel Ther, 2018;12:303-312.
    PMID: 29491706 DOI: 10.2147/DDDT.S156123
    BACKGROUND: Berberine is an isoquinoline alkaloid widely used in Ayurveda and traditional Chinese medicine to treat illnesses such as hypertension and inflammatory conditions, and as an anticancer and hepato-protective agent. Berberine has low oral bioavailability due to poor aqueous solubility and insufficient dissolution rate, which can reduce the efficacy of drugs taken orally. In this study, evaporative precipitation of nanosuspension (EPN) and anti-solvent precipitation with a syringe pump (APSP) were used to address the problems of solubility, dissolution rate and bioavailability of berberine.

    METHODS: Semi-crystalline nanoparticles (NPs) of 90-110 nm diameter for APSP and 65-75 nm diameter for EPN were prepared and then characterized using differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRD). Thereafter, drug content solubility and dissolution studies were undertaken. Berberine and its NPs were evaluated for their antibacterial activity.

    RESULTS: The results indicate that the NPs have significantly increased solubility and dissolution rate due to conversion of the crystalline structure to a semi-crystalline form.

    CONCLUSION: Berberine NPs produced by both APSP and EPN methods have shown promising activities against Gram-positive and Gram-negative bacteria, and yeasts, with NPs prepared through the EPN method showing superior results compared to those made with the APSP method and the unprocessed drug.

    Matched MeSH terms: Calorimetry, Differential Scanning
  19. Development and characterization of lecithin stabilized glibenclamide nanocrystals for enhanced solubility and drug delivery
    Kumar BS, Saraswathi R, Kumar KV, Jha SK, Venkates DP, Dhanaraj SA
    Drug Deliv, 2014 May;21(3):173-84.
    PMID: 24102185 DOI: 10.3109/10717544.2013.840690
    Novel LNCs (lipid nanocrystals) were developed with an aim to improve the solubility, stability and targeting efficiency of the model drug glibenclamide (GLB). PEG 20000, Tween 80 and soybean lecithin were used as polymer, surfactant and complexing agent, respectively. GLB nanocrystals (NCs) were prepared by precipitation process and complexed using hot and cold melt technique. The LNCs were evaluated by drug loading, saturation solubility (SL), optical clarity, in vitro dissolution, solid state characterization, in vivo and stability analysis. LNCs exhibited a threefold increase in SL and a higher dissolution rate than GLB. The percentage dissolution efficiency was found to decrease with increase in PEG 20000. The average particle size was in the range of 155-842 nm and zeta potential values tend to increase after complexation. X-ray powder diffractometry and differential scanning calorimetry results proved the crystallinity prevailed in the samples. Spherical shaped particles (<1000 nm) with a lipid coat on the surface were observed in scanning electron microscopy analysis. Fourier transform infrared results proved the absence of interaction between drug and polymer and stability study findings proved that LNCs were stable. In vivo study findings showed a decrease in drug concentration to pancreas in male Wistar rats. It can be concluded that LNCs are could offer enhanced solubility, dissolution rate and stability for poorly water soluble drugs. The targeting efficiency of LNCs was decreased and further membrane permeability studies ought to be carried out.
    Matched MeSH terms: Calorimetry, Differential Scanning
  20. Fulltext Rehydrated sterically stabilized phospholipid nanomicelles of budesonide for nebulization: physicochemical characterization and in vitro, in vivo evaluations
    Sahib MN, Darwis Y, Peh KK, Abdulameer SA, Tan YT
    Int J Nanomedicine, 2011;6:2351-66.
    PMID: 22072872 DOI: 10.2147/IJN.S25363
    Inhaled corticosteroids provide unique systems for local treatment of asthma or chronic obstructive pulmonary disease. However, the use of poorly soluble drugs for nebulization has been inadequate, and many patients rely on large doses to achieve optimal control of their disease. Theoretically, nanotechnology with a sustained-release formulation may provide a favorable therapeutic index. The aim of this study was to determine the feasibility of using sterically stabilized phospholipid nanomicelles of budesonide for pulmonary delivery via nebulization.
    Matched MeSH terms: Calorimetry, Differential Scanning
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