scholarly journals Tuning the Transdermal Delivery of Hydroquinone upon Formulation with Novel Permeation Enhancers

Pharmaceutics ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 167 ◽  
Author(s):  
Dolores R. Serrano ◽  
María José Gordo ◽  
Antonio Matji ◽  
Salvador González ◽  
Aikaterini Lalatsa ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Droplet Size ◽  
Transdermal Delivery ◽  
Mouse Skin ◽  
Inverse Correlation ◽  
Permeation Enhancers ◽  
Steady State Flux ◽  
Physicochemical Stability ◽  
Chromatic Aberrations ◽  
The Mean

Hydroquinone (HQ) is an anti-hyperpigmentation agent with poor physicochemical stability. HQ formulations are currently elaborated by compounding in local pharmacies. Variability in the characteristics of HQ topical formulations can lead to remarkable differences in terms of their stability, efficacy, and toxicity. Four different semisolid O/W formulations with 5% HQ were prepared using: i) Beeler´s base plus antioxidants (F1), ii) Beeler´s base and dimethyl isosorbide (DMI) as solubiliser (F2), iii) olive oil and DMI (F3), and iv) Nourivan®, a skin-moisturising and antioxidant base, along with DMI (F4). Amongst the four formulations, F3 showed the greatest physicochemical stability with less tendency to coalescence but with marked chromatic aberrations. An inverse correlation was established by multivariate analysis between the mean droplet size in volume and the steady-state flux, which explains why F3, with the smallest droplet size and the most hydrophobic excipients, exhibited the highest permeation across both types of membranes with enhancement ratios of 2.26 and 5.67-fold across Strat-M® and mouse skin, respectively, compared to F1. It is crucial to understand how the HQ is formulated, bearing in mind that the use of different excipients can tune the transdermal delivery of HQ significantly.

Transdermal Delivery of Acyclovir Sodium Via Carbopol Gels: Role of Chemical Permeation Enhancers

2011 ◽  
Vol 8 (4) ◽  
pp. 381-389 ◽  
Author(s):  
Raju Jukanti ◽  
Ashok Mateti ◽  
Suresh Bandari ◽  
Prabhakar R Veerareddy
Keyword(s):  
Transdermal Delivery ◽  
Permeation Enhancers ◽  
Chemical Permeation Enhancers ◽  
Chemical Permeation

scholarly journals Influence ofABCC2andABCC4Polymorphisms on Tenofovir Plasma Concentrations in Thai HIV-Infected Patients

2015 ◽  
Vol 59 (6) ◽  
pp. 3240-3245 ◽  
Author(s):  
Kanokrat Rungtivasuwan ◽  
Anchalee Avihingsanon ◽  
Narukjaporn Thammajaruk ◽  
Siwaporn Mitruk ◽  
David M. Burger ◽  
...  
Keyword(s):  
Body Weight ◽  
Multivariate Analysis ◽  
Plasma Concentration ◽  
Protease Inhibitors ◽  
Demographic Data ◽  
Plasma Concentrations ◽  
Multidrug Resistant ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
The Mean

ABSTRACTTenofovir (TFV) is eliminated by renal excretion, which is mediated through multidrug-resistant protein 2 (MRP2) and MRP4, encoded byABCC2andABCC4, respectively. Genetic polymorphisms of these transporters may affect the plasma concentrations of tenofovir. Therefore, the aim of this study was to investigate the influence of genetic and nongenetic factors on tenofovir plasma concentrations. A cross-sectional study was performed in Thai HIV-infected patients aged ≥18 years who had been receiving tenofovir disoproxil fumarate at 300 mg once daily for at least 6 months. A middose tenofovir plasma concentration was obtained. Multivariate analysis was performed to investigate whether there was an association between tenofovir plasma concentrations and demographic data, including age, sex, body weight, estimated glomerular filtration rate (eGFR), hepatitis B virus coinfection, hepatitis C virus coinfection, duration of tenofovir treatment, concomitant use of ritonavir-boosted protease inhibitors, and polymorphisms ofABCC2andABCC4. A total of 150 Thai HIV-infected patients were included. The mean age of the patients was 43.9 ± 7.2 years. The mean tenofovir plasma concentration was 100.3 ± 52.7 ng/ml. In multivariate analysis, a low body weight, a low eGFR, the concomitant use of ritonavir-boosted protease inhibitors, and theABCC44131T → G variation (genotype TG or GG) were independently associated with higher tenofovir plasma concentrations. After adjusting for weight, eGFR, and the concomitant use of ritonavir-boosted protease inhibitors, a 30% increase in the mean tenofovir plasma concentration was observed in patients having theABCC44131 TG or GG genotype. Both genetic and nongenetic factors affect tenofovir plasma concentrations. These factors should be considered when adjusting tenofovir dosage regimens to ensure the efficacy and safety of a drug. (This study has been registered at ClinicalTrials.gov under registration no. NCT01138241.)

Estimating the intra- and inter-individual imprecision of manual pipetting

2017 ◽  
Vol 55 (7) ◽  
Author(s):  
Giuseppe Lippi ◽  
Gabriel Lima-Oliveira ◽  
Giorgio Brocco ◽  
Antonella Bassi ◽  
Gian Luca Salvagno
Keyword(s):  
Coefficient Of Variation ◽  
Biological Samples ◽  
Inverse Correlation ◽  
Distilled Water ◽  
Years Of Experience ◽  
Laboratory Practice ◽  
Scientific Publications ◽  
Plastic Container ◽  
Water Solutions ◽  
The Mean

AbstractBackground:Despite the importance of manual pipetting of fluids such as water, solutions, buffers, reagents, or biological samples in daily laboratory practice, the intra- and inter-individual imprecision of this activity has not been recently described in scientific publications.Methods:Twenty laboratory operators were randomly enrolled for this study. Imprecision of manual pipetting was estimated by asking each laboratory professional to dispense 1 mL, 100 μL or 10 μL of distilled water for 10 consecutive times with three certified pipettes into a 50-mL plastic container placed into a gravimetric balance. The weight of the water dispensed was systematically recorded for each of the 10 repeated attempts, and the inter- and intra-operator imprecision was finally calculated and expressed as coefficient of variation (CV%).Results:The mean intra-individual imprecision was 5.7% (range, 0%–11.8%) for pipetting 10 μL, 0.8% (range, 0.4%–1.9%) for pipetting 100 μL, and 0.2% (range, 0.1%–0.5%) for pipetting 1 mL. Overall, the mean inter-individual imprecision was 8.1% for pipetting 10 μL, 1.1% for pipetting 100 μL and 0.4% for pipetting 1 mL. A significantly inverse correlation was found between intra-individual pipetting imprecision and the amount of water dispensed (r = –0.80; p<0.001). No significant correlation was observed between individual pipetting performance and sex, age, qualification, and years of experience in the laboratory.Conclusions:The results of this study show that manual pipetting is plagued by a considerable intra- and inter-individual imprecision, which is inversely correlated with the amount of fluid dispensed.

scholarly journals Biological and physicochemical stability of ceftazidime and aminophylline on glucose parenteral solution

2012 ◽  
Vol 48 (4) ◽  
pp. 691-698
Author(s):  
Carolina Alves dos Santos ◽  
Laura Oliveira-Nascimento ◽  
Marcos Camargo Knirsch ◽  
Marco Antônio Stephano ◽  
Adalberto Pessoa Júnior ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
High Performance ◽  
Inhibitory Concentration ◽  
Serum Levels ◽  
High Loss ◽  
Physicochemical Stability ◽  
Physicochemical Evaluation ◽  
The Mean ◽  
The Stability

Ceftazidime is a broad spectrum antibiotic administered mainly by the parenteral route, and it is especially effective against Pseudomonas aeruginosa. The period of time in which serum levels exceed the Minimum Inhibitory Concentration (MIC) is an important pharmacodynamic parameter for its efficacy. One of the forms to extend this period is to administer the antibiotic by continuous infusion, after prior dilution in a Parenteral Solution (PS). The present work assessed the stability of ceftazidime in 5% glucose PS for 24 hours, combined or not with aminophylline, through High Performance Liquid Chromatography (HPLC). The physicochemical evaluation was accompanied by in vitro antimicrobial activity compared MIC test in the 24-hour period. Escherichia coli and Pseudomonas aeruginosa were the microorganisms chosen for the MIC comparison. The HPLC analysis confirmed ceftazidime and aminophylline individual stability on PS, while the MIC values were slightly higher than the mean described in the literature. When both drugs were associated in the same PS, the ceftazidime concentration by HPLC decreased 25% after 24 hours. Not only did the MIC values show high loss of antibiotic activity within the same period, but also altered MIC values immediately after the preparation, which was not detected by HPLC. Our results indicate that this drug combination is not compatible, even if used right away, and that PS might not be the best vehicle for ceftazidime, emphasizing the importance of the MIC evaluation for drug interactions.

scholarly journals Broadening of Cloud Droplet Spectra through Eddy Hopping: Turbulent Entraining Parcel Simulations

2018 ◽  
Vol 75 (10) ◽  
pp. 3365-3379 ◽  
Author(s):  
Gustavo C. Abade ◽  
Wojciech W. Grabowski ◽  
Hanna Pawlowska
Keyword(s):  
Droplet Size ◽  
Turbulent Mixing ◽  
Cloud Condensation Nuclei ◽  
Cloud Droplet ◽  
Cloud Microphysics ◽  
Droplet Growth ◽  
Size Spectrum ◽  
Entrainment Rate ◽  
The Mean ◽  
The Impact

This paper discusses the effects of cloud turbulence, turbulent entrainment, and entrained cloud condensation nuclei (CCN) activation on the evolution of the cloud droplet size spectrum. We simulate an ensemble of idealized turbulent cloud parcels that are subject to entrainment events modeled as a random process. Entrainment events, subsequent turbulent mixing inside the parcel, supersaturation fluctuations, and the resulting stochastic droplet activation and growth by condensation are simulated using a Monte Carlo scheme. Quantities characterizing the turbulence intensity, entrainment rate, CCN concentration, and the mean fraction of environmental air entrained in an event are all specified as independent external parameters. Cloud microphysics is described by applying Lagrangian particles, the so-called superdroplets. These are either unactivated CCN or cloud droplets that grow from activated CCN. The model accounts for the addition of environmental CCN into the cloud by entraining eddies at the cloud edge. Turbulent mixing of the entrained dry air with cloudy air is described using the classical linear relaxation to the mean model. We show that turbulence plays an important role in aiding entrained CCN to activate, and thus broadening the droplet size distribution. These findings are consistent with previous large-eddy simulations (LESs) that consider the impact of variable droplet growth histories on the droplet size spectra in small cumuli. The scheme developed in this work is ready to be used as a stochastic subgrid-scale scheme in LESs of natural clouds.

scholarly journals Volume of the ligamentum capitis femoris in osteoarthritic hip joints of adult dogs

2003 ◽  
Vol 74 (1) ◽  
Author(s):  
J.D. Mande ◽  
P.M.F. Mbithi ◽  
S.W. Mbugua ◽  
I.B.J. Buoro ◽  
P.K. Gathumbi
Keyword(s):  
General Anaesthesia ◽  
Crucial Role ◽  
Hip Dysplasia ◽  
Inverse Correlation ◽  
Water Displacement ◽  
Hip Joints ◽  
Ligamentum Capitis Femoris ◽  
The Mean ◽  
Canine Hip Dysplasia

Ventrodorsal pelvic radiographs were made of 32 adult dogs under general anaesthesia. The hip joints were evaluated according to the severity of osteoarthritic changes graded as 0, 1, 2 or 3. The dogs were euthanased, the hip joints opened and the ligamentum capitis femoris dissected out in toto. The volume of each ligament was determined using a water displacement technique and the mean volume compared to the four radiographic grades of osteoarthritis. There was an inverse correlation (r = -0.75) between the mean volume of the ligamentum capitis femoris and the increasing severity of osteoarthritis as assessed by radiography. The results confirmed the crucial role of radiography in the clinical evaluation of hip dysplasia and osteoarthritis in the adult dog. Assessment of the volume of the ligamentum capitis femoris revealed that it is an important tool for research in canine hip dysplasia and osteoarthritis.

scholarly journals Open and laparoscopic approaches are associated with comparable 90-day morbidity and mortality following ERAS protocol

2020 ◽  
Author(s):  
Bhavin B. Vasavada ◽  
Hardik Patel
Keyword(s):  
Multivariate Analysis ◽  
Operative Time ◽  
Univariate Analysis ◽  
Operating Time ◽  
Morbidity And Mortality ◽  
Morbidity Rate ◽  
Blood Products ◽  
Mortality And Morbidity ◽  
The Mean ◽  
Eras Protocol

ABSTRACTIntroductionThe aim of this study is to compare 90-day mortality and morbidity between open and laparoscopic surgeries performed in one centre since the introduction of ERAS protocols.Material and MethodsAll gastrointestinal surgeries performed between April 2016 and March 2019 at our institution after the introduction of ERAS protocols have been analysed for morbidity and mortality. The analysis was performed in a retrospective manner using data from our prospectively maintained database.ResultsWe performed 245 gastrointestinal and hepatobiliary surgeries between April 2016 and March 2019. The mean age of patients was 50.96 years. 135 were open surgeries and 110 were laparoscopic surgeries. The mean ASA score was 2.4, the mean operative time was 111 minutes and the mean CDC grade of surgery was 2.56. 40 were emergency surgeries and 205 were elective surgeries. Overall the 90-day mortality rate was 8.5% and the morbidity rate was around 9.79%. On univariate analysis morbidity was associated with a higher CDC grade of surgeries, a higher ASA grade, longer operating time, the use of more blood products, a longer hospital stay and open surgeries. HPB surgeries and luminal surgeries (non hpb gastrointestinal surgeries) were associated with 90 day post operative morbidity. On multivariate analysis no factors independently predicted morbidity. On univariate analysis 90-day mortality was predicted by the grade of surgeries, a higher ASA grade, longer operative time, the use of more blood products, open surgeries and emergency surgeries. However on multivariate analysis only the use of more blood products was independently associated with mortalityConclusionThe 90-day mortality and morbidity rates between open and laparoscopic surgeries after the introduction of ERAS protocol were similar.

Effect of Low Molecular Weight Chitosans on Drug Permeation through Mouse Skin: 1. Transdermal Delivery of Baicalin

2010 ◽  
Vol 99 (7) ◽  
pp. 2991-2998 ◽  
Author(s):  
Xueqin Zhou ◽  
Dongzhi Liu ◽  
Haiyan Liu ◽  
Qiaoli Yang ◽  
Kangde Yao ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Transdermal Delivery ◽  
Mouse Skin ◽  
Low Molecular Weight ◽  
Drug Permeation

scholarly journals Platelet-rich clots as identified by Martius Scarlet Blue staining are isodense on NCCT

2019 ◽  
Vol 11 (11) ◽  
pp. 1145-1149 ◽  
Author(s):  
Sean T Fitzgerald ◽  
Shunli Wang ◽  
Daying Dai ◽  
Andrew Douglas ◽  
Ramanathan Kadirvel ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Inverse Correlation ◽  
Clinical Information ◽  
Blue Staining ◽  
Histopathological Analysis ◽  
Blue Stain ◽  
The Mean ◽  
Learning Software ◽  
Ct Density

BackgroundCurrent studies on clot characterization in acute ischemic stroke focus on fibrin and red blood cell composition. Few studies have examined platelet composition in acute ischemic stroke clots. We characterize clot composition using the Martius Scarlet Blue stain and assess associations between platelet density and CT density.Materials and methodHistopathological analysis of the clots collected as part of the multi-institutional STRIP registry was performed using Martius Scarlet Blue stain and the composition of the clots was quantified using Orbit Image Analysis (www.orbit.bio) machine learning software. Prior to endovascular treatment, each patient underwent non-contrast CT (NCCT) and the CT density of each clot was measured. Correlations between clot components and clinical information were assessed using the χ2 test.ResultsEighty-five patients were included in the study. The mean platelet density of the clots was 15.7% (2.5–72.5%). There was a significant correlation between platelet-rich clots and the absence of hyperdensity on NCCT, (ρ=0.321, p=0.003*, n=85). Similarly, there was a significant inverse correlation between the percentage of platelets and the mean Hounsfield Units on NCCT (ρ=−0.243, p=0.025*, n=85).ConclusionMartius Scarlet Blue stain can identify patients who have platelet-rich clots. Platelet-rich clots are isodense on NCCT.

Corticosteroid receptors and lymphocyte subsets in mononuclear leukocytes in aging

1992 ◽  
Vol 262 (4) ◽  
pp. E464-E466 ◽  
Author(s):  
D. Armanini ◽  
I. Karbowiak ◽  
M. Scali ◽  
E. Orlandini ◽  
V. Zampollo ◽  
...  
Keyword(s):  
Lymphocyte Subsets ◽  
Inverse Correlation ◽  
Plasma Aldosterone ◽  
Mononuclear Leukocytes ◽  
Type I ◽  
Type Ii ◽  
Significant Inverse Correlation ◽  
Corticosteroid Receptors ◽  
The Mean ◽  
Aged Subjects

Plasma cortisol and aldosterone levels and number of related receptors in mononuclear leukocytes were measured in 49 healthy aged subjects (62-97 yr) and in 21 adult controls (21-50 yr). In all subjects, in addition, lymphocyte subsets were determined as an index of corticosteroid action. The mean number of type I and type II receptors was significantly lower in aged subjects than in controls (respectively, 198 +/- 96 and 272 +/- 97 receptors/cell for type I, and 1,794 +/- 803 and 3,339 +/- 918 for type II receptors). Plasma aldosterone and cortisol and lymphocyte subsets were not different in the two groups. All of the parameters were also tested for correlation, and a significant inverse correlation was found between age and type I and type II receptors when all subjects were plotted and between aged and CD4 and age and CD4/CD8 in the aged group. These data show that aged subjects have reductions of corticosteroid receptors that are not associated with increase of related steroids and that this situation probably represents a concomitant of the normal aging process.

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