scholarly journals In vitro quality assessment of ten brands of metronidazole benzoate suspensions marketed in Warri, Nigeria

2020 ◽  
Vol 13 (2) ◽  
pp. 190-198
Author(s):  
Nkemakolam Nwachukwu ◽  
Edwin Aboje Ubieko
Keyword(s):  
Quality Assessment ◽  
Flow Rate ◽  
Volume Flow Rate ◽  
Color Variation ◽  
Label Information ◽  
Label Claim ◽  
Sedimentation Volume ◽  
Drug Regulatory Agencies ◽  
Metronidazole Benzoate

Therapeutic failure as a result of high incidence of fake, adulterated, counterfeit and substandard drugs usage is a major concern to health practitioners, drug regulatory agencies, drug consumers and the general public in Nigeria. The objective of this study was to carry out in vitro quality assessment/evaluation of ten (10) different brands of metronidazole benzoate suspensions that are marketed in Warri, Nigeria. Metronidazole benzoate suspensions (10 brands) were purchased from some pharmacies in Warri, Nigeria. They were checked for the label information on both the secondary and primary packages, physical examination of the primary containers for tampering/breakage of seal on cap, organoleptic properties, pH, sedimentation volume, flow rate, viscosity, redispersibility and content of active ingredient/assay using standard methods. Results obtained showed that the suspensions had the necessary information on their labels, the containers were not tampered with in order to access or change their content. All the brands tested showed good results for color variation, pH, viscosity, flow rate, sedimentation, and redispersibility. All the brands met with their label claims of metronidazole benzoate content based on British Pharmacopoeia specification [95 - 105 %] except one brand (MET-A), that failed. Generally, nine of the brands representing 90 % met with their label claim and can be considered fit for distribution and consumption.

In Vitro Performance Assessment of Distal Protection Devices for Carotid Artery Stenting: Effect of Physiological Anatomy on Vascular Resistance

2007 ◽  
Vol 14 (5) ◽  
pp. 712-724 ◽  
Author(s):  
Gail M. Siewiorek ◽  
Mark H. Wholey ◽  
Ender A. Finol
Keyword(s):  
Carotid Artery ◽  
Pressure Gradient ◽  
Vascular Resistance ◽  
Flow Rate ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Physiological Anatomy ◽  
Protection Devices ◽  
Distal Protection

Purpose: To assess in vitro the performance of 5 distal protection devices (DPDs) by evaluating the capture efficiency, pressure gradient, volume flow rate, and vascular resistance in the internal carotid artery (ICA). Methods: The time-averaged mean peak velocity in the common carotid artery and a blood-mimicking solution were used to simulate physiological conditions in a silicone carotid phantom representing average human carotid artery geometry with a 70% symmetrical ICA stenosis. Five milligrams of dyed 200-μm nominal diameter polymer microspheres (larger than the pore size of the devices, except Spider RX, which was tested with 300-μm-diameter particles) were injected into the ICA. The percentages of particles missed after injection and lost during device retrieval were measured for the 5 devices (Spider RX, FilterWire EZ, RX Accunet, Angioguard XP, and Emboshield). The normalized pressure gradient, fraction of the volume flow rate, and vascular resistance in the ICA were calculated. Results: Spider RX captured the most particles (missing 0.06%, p<0.05) and yielded the smallest normalized pressure gradient increase (4.2%), the largest volume flow rate fraction (0.40), and the smallest vascular resistance in the ICA (272 mmHg/L·min−1, a 5.4% increase with respect to initial conditions). Angioguard XP captured the fewest particles (missing 36.3%, p<0.05 except Emboshield) and resulted in the largest normalized pressure gradient increase (37%) in the ICA. RX Accunet produced the smallest volume flow rate fraction in the ICA (0.30) and the largest vascular resistance in the ICA (470 mmHg/L·min−1, an 82.2% increase). Emboshield migrated ∼6 cm distal to the original position after particle injection. FilterWire EZ lost the fewest particles during retrieval (0.45%, p<0.05 except Accunet RX and Spider RX) and had the best overall performance with 200-μm emboli (p<0.05 except Accunet RX). Conclusion: None of the devices tested completely prevented embolization. Overall, Spider RX had the best performance and is conjectured to have the best wall apposition of the devices tested. Vascular resistance should be considered a key filter design parameter for performance testing since it represents a quantitative estimation of the “slow-flow phenomenon.” Our findings should be extrapolated cautiously to help interventionists choose the best device.

scholarly journals EVALUATION OF THE SUSPENDING PROPERTIES OF A NEW PLANT GUM IN SULPHAMETOXAZOLE FORMULATIONS

2017 ◽  
pp. 47-50
Author(s):  
John Oluwasogo AYORINDE ◽  
Michael Ayodele ODENIYI
Keyword(s):  
Flow Rate ◽  
Volume Flow Rate ◽  
Dosage Forms ◽  
Volume Flow ◽  
Effect Of Temperature ◽  
Cedrela Odorata ◽  
Natural Polymer ◽  
Sedimentation Volume ◽  
Suspending Agents ◽  
Natural Gum

Suspension dosage forms require the use of suspending agents in order to deliver a uniform dose of the active ingredient. The purpose of this study is to investigate the properties of a new plant gum as a cheap and effective natural polymer in the formulation of pharmaceutical suspensions. The gum obtained from the incised trunk of Cedrela odorata (family Meliaceae) was compared with hydroxypropylmethylcellulose and gelatin in Sulphamethoxazole suspension formulations at concentrations of 1.0 – 4.0%w/w. Assessment parameters were sedimentation volume, flow rate, viscosity and the effect of temperature on these parameters. The suspending characteristics of Cedrela gum compared well with that of hydroxypropylmethylcellulose in term of sedimentation volume, flow rate and viscosity and the natural gum could be used as a substitute in pharmaceutical suspensions.

scholarly journals Evaluation of Grewia ferruginea Hochst ex A. Rich Mucilage as Suspending Agent in Metronidazole Benzoate Suspension

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Tsadkan Gebremeskel Haile ◽  
Gereziher Gebremedhin Sibhat ◽  
Ebisa Tadese ◽  
Desta Tesfay ◽  
Fantahun Molla
Keyword(s):  
In Vitro Release ◽  
Flow Characteristics ◽  
Methyl Cellulose ◽  
Storage Conditions ◽  
Stability Study ◽  
Release Profile ◽  
Drug Release Profile ◽  
Sedimentation Volume ◽  
Metronidazole Benzoate

Various species of the genus Grewia have been investigated for different pharmaceutical applications as excipients, yet a study on the potential use of Grewia ferruginea mucilage (GFM) as a suspending agent is lacking. Thus, this study is aimed at evaluating the efficacy of Grewia ferruginea mucilage (GFM) as a suspending agent in metronidazole benzoate suspension. The suspensions were prepared using 0.5%, 1%, 1.5%, and 2% w / v of GFM and compared with suspensions prepared from xanthan gum (XGM) and sodium carboxyl methyl cellulose (SCMC) in similar concentrations. The prepared suspensions were evaluated for visual appearance, pH, rheology, sedimentation volume, redispersibility, degree of flocculation, and in vitro drug release profile. Stability study was done at different storage conditions for three months. The results indicated that all the prepared suspension formulations exhibited pseudoplastic flow characteristics with viscosity imparting ability of the suspending agents in the order of XGM > GFM > SCMC ( p < 0.05 ). The flow rate and redispersibility of the formulations prepared with GFM were significantly lower than those with SCMC and higher than those prepared with XGM. At 0.5% w / v suspending agent concentrations, the sedimentation volume of the formulations was in the order of XGM > GFM > SCMC ( p < 0.05 ). However, at all other concentrations, the sedimentation volume of the formulations prepared with GFM had similar results with XGM but exhibited significantly higher sedimentation volume than SCMC. The formulations with GFM showed a higher degree of flocculation at 0.5% w / v concentration but were comparable at 1.5% w / v with XGM containing formulations. The pH, assay, and in vitro release profile of all assessed formulations were within the pharmacopial limit. Thus, based on the finding of this study, it can be concluded that Grewia ferruginea bark mucilage has the potential to be utilized as a suspending agent in suspension formulations.

scholarly journals Formulation and In Vitro Evaluation of Oral Capsules and Suspension from the Ethanolic Extract of Cola nitida Seeds for the Treatment of Diarrhea

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Fredrick W. A. Owusu ◽  
Christiana O. Asare ◽  
Philomena Enstie ◽  
Ofosua Adi-Dako ◽  
Genevieve Naana Yeboah ◽  
...  
Keyword(s):  
Flow Rate ◽  
Sedimentation Rate ◽  
In Vitro Release ◽  
Ethanolic Extract ◽  
Dosage Forms ◽  
Drug Content ◽  
Sedimentation Volume ◽  
Vitro Release ◽  
Cola Nitida

Management of diarrhea has evolved over the years from relatively inadequate interventions in the early years to more successful physiological approaches. The use of herbal medicinal products and supplements has grown significantly over the past three decades, with more than half of the global population depending on it for some aspect of their primary health care needs. This study is aimed at formulating solid and liquid oral dosage forms of the ethanolic extract of Cola nitida seeds for the treatment of diarrhea. The flow property of the dried ethanolic extract was determined and subsequently formulated into granules for encapsulation. The ethanolic extract was also used in formulating an oral suspension. Pharmacopeia tests such as uniformity of weight, disintegration, drug content, and dissolution were carried out on the formulated capsules. The formulated suspension was also assessed using the following parameters; viscosity, flow rate, drug content, dissolution, sedimentation rate, and sedimentation volume. The dried ethanolic extract and formulated granules exhibited good flow properties. The formulated capsules exhibited optimal in vitro release of extract (>90% after 45 minutes) and passed the uniformity of weight, disintegration, and drug content tests. The formulated suspension also passed the drug content test and had a good sedimentation rate, sedimentation volume, and flow rate. The formulated suspension also exhibited pseudoplastic flow, optimal viscosity, and a good in vitro release profile (>90% after 45 minutes). Capsules and suspension of the ethanolic extract of Cola nitida seeds have been successfully formulated and can be used as standard dosage forms for the management of diarrhea.

Novel epoxy/anhydride alternatives for biological electron microscopy: Physical and performance characteristis of embed 812 and LX 112 in combination with NSA/NMA/DMAE

1989 ◽  
Vol 47 ◽  
pp. 1000-1001
Author(s):  
Joe A. Mascorro ◽  
Gerald S. Kirby
Keyword(s):  
Electron Microscopy ◽  
Flow Rate ◽  
Succinic Anhydride ◽  
Volume Flow Rate ◽  
Mass Density ◽  
Uranyl Acetate ◽  
Volume Flow ◽  
Base Resin ◽  
And Performance ◽  
Acid Anhydrides

Embedding media based upon an epoxy resin of choice and the acid anhydrides dodecenyl succinic anhydride (DDSA), nadic methyl anhydride (NMA), and catalyzed by the tertiary amine 2,4,6-Tri(dimethylaminomethyl) phenol (DMP-30) are widely used in biological electron microscopy. These media possess a viscosity character that can impair tissue infiltration, particularly if original Epon 812 is utilized as the base resin. Other resins that are considerably less viscous than Epon 812 now are available as replacements. Likewise, nonenyl succinic anhydride (NSA) and dimethylaminoethanol (DMAE) are more fluid than their counterparts DDSA and DMP- 30 commonly used in earlier formulations. This work utilizes novel epoxy and anhydride combinations in order to produce embedding media with desirable flow rate and viscosity parameters that, in turn, would allow the medium to optimally infiltrate tissues. Specifically, embeding media based on EmBed 812 or LX 112 with NSA (in place of DDSA) and DMAE (replacing DMP-30), with NMA remaining constant, are formulated and offered as alternatives for routine biological work.Individual epoxy resins (Table I) or complete embedding media (Tables II-III) were tested for flow rate and viscosity. The novel media were further examined for their ability to infilftrate tissues, polymerize, sectioning and staining character, as well as strength and stability to the electron beam and column vacuum. For physical comparisons, a volume (9 ml) of either resin or media was aspirated into a capillary viscocimeter oriented vertically. The material was then allowed to flow out freely under the influence of gravity and the flow time necessary for the volume to exit was recored (Col B,C; Tables). In addition, the volume flow rate (ml flowing/second; Col D, Tables) was measured. Viscosity (n) could then be determined by using the Hagen-Poiseville relation for laminar flow, n = c.p/Q, where c = a geometric constant from an instrument calibration with water, p = mass density, and Q = volume flow rate. Mass weight and density of the materials were determined as well (Col F,G; Tables). Infiltration schedules utilized were short (1/2 hr 1:1, 3 hrs full resin), intermediate (1/2 hr 1:1, 6 hrs full resin) , or long (1/2 hr 1:1, 6 hrs full resin) in total time. Polymerization schedules ranging from 15 hrs (overnight) through 24, 36, or 48 hrs were tested. Sections demonstrating gold interference colors were collected on unsupported 200- 300 mesh grids and stained sequentially with uranyl acetate and lead citrate.

Dependence of Blood Clot Lysis on the Mode of Transport of Urokinase into the Clot - A Magnetic Resonance Imaging Study in Vitro

1991 ◽  
Vol 65 (05) ◽  
pp. 549-552 ◽  
Author(s):  
A Blinc ◽  
G Planinšič ◽  
D Keber ◽  
O Jarh ◽  
G Lahajnar ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Pressure Difference ◽  
Volume Flow Rate ◽  
Blood Clot ◽  
Linear Regression Analysis ◽  
Imaging Study ◽  
Clot Lysis ◽  
Resonance Imaging

SummaryMagnetic resonance imaging was employed to study the dependence of clot lysing patterns on two different modes of transport of urokinase into whole blood clots. In one group of clots (nonperfused clots, n1 = 10), access of urokinase to the fibrin network was possible by diffusion only, whereas in the other group (perfused clots, n2 = 10) bulk flow of plasma containing urokinase was instituted through occlusive clots by a pressure difference of 3 .7 kPa (37 cm H2O) across 3 cm long clots with a diameter of 4 mm. It was determined separately that this pressure difference resulted in a volume flow rate of 5.05 ± 2.4 × 10−2 ml/min through occlusive clots. Perfused clots diminished in size significantly in comparison to nonperfused ones already after 20 min (p <0.005). Linear regression analysis of two-dimensional clot sizes measured by MRI showed that the rate of lysis was more than 50-times faster in the perfused group in comparison to the nonperfused group. It was concluded that penetration of the thrombolytic agent into clots by perfusion is much more effective than by diffusion. Our results might have some implications for understanding the differences in lysis of arterial and venous thrombi.

scholarly journals The versatility of external quality assessment for the surveillance of laboratory and in vitro diagnostic performance: SARS-CoV-2 viral genome detection in Austria

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Christoph Buchta ◽  
Jeremy V. Camp ◽  
Jovana Jovanovic ◽  
Peter Chiba ◽  
Elisabeth Puchhammer-Stöckl ◽  
...  
Keyword(s):  
Quality Assessment ◽  
External Quality Assessment ◽  
False Negative ◽  
Positive Sample ◽  
Performance Criteria ◽  
External Quality ◽  
Assay Sensitivity ◽  
Dilution Series ◽  
Test Systems

Abstract Objectives External quality assessment (EQA) schemes provide information on individual and general analytical performance of participating laboratories and test systems. The aim of this study was to investigate the use and performance of SARS-CoV-2 virus genome detection systems in Austrian laboratories and their preparedness to face challenges associated with the pandemic. Methods Seven samples were selected to evaluate performance and estimate variability of reported results. Notably, a dilution series was included in the panel as a measure of reproducibility and sensitivity. Several performance criteria were evaluated for individual participants as well as in the cohort of all participants. Results A total of 109 laboratories participated and used 134 platforms, including 67 different combinations of extraction and PCR platforms and corresponding reagents. There were no false positives and 10 (1.2%) false negative results, including nine in the weakly positive sample (C t ∼35.9, ∼640 copies/mL). Twenty (22%) laboratories reported results of mutation detection. Twenty-five (19%) test systems included amplification of human RNA as evidence of proper sampling. The overall linearity of C t values from individual test systems for the dilution series was good, but inter-assay variability was high. Both operator-related and systematic failures appear to have caused incorrect results. Conclusions Beyond providing certification for participating laboratories, EQA provides the opportunity for participants to evaluate their performance against others so that they may improve operating procedures and test systems. Well-selected EQA samples offer additional inferences to be made about assay sensitivity and reproducibility, which have practical applications.

scholarly journals Angiotensin II stimulates trafficking of NHE3, NaPi2, and associated proteins into the proximal tubule microvilli

2010 ◽  
Vol 298 (1) ◽  
pp. F177-F186 ◽  
Author(s):  
Anne D. M. Riquier-Brison ◽  
Patrick K. K. Leong ◽  
Kaarina Pihakaski-Maunsbach ◽  
Alicia A. McDonough
Keyword(s):  
Angiotensin Ii ◽  
Proximal Tubule ◽  
Flow Rate ◽  
Enzyme Inhibitor ◽  
Volume Flow Rate ◽  
Ang Ii ◽  
Sprague Dawley ◽  
Water Reabsorption ◽  
Associated Proteins ◽  
Gradient Fractionation

Angiotensin II (ANG II) stimulates proximal tubule (PT) sodium and water reabsorption. We showed that treating rats acutely with the angiotensin-converting enzyme inhibitor captopril decreases PT salt and water reabsorption and provokes rapid redistribution of the Na+/H+ exchanger isoform 3 (NHE3), Na+/Pi cotransporter 2 (NaPi2), and associated proteins out of the microvilli. The aim of the present study was to determine whether acute ANG II infusion increases the abundance of PT NHE3, NaPi2, and associated proteins in the microvilli available for reabsorbing NaCl. Male Sprague-Dawley rats were infused with a dose of captopril (12 μg/min for 20 min) that increased PT flow rate ∼20% with no change in blood pressure (BP) or glomerular filtration rate (GFR). When ANG II (20 ng·kg−1·min−1 for 20 min) was added to the captopril infusate, PT volume flow rate returned to baseline without changing BP or GFR. After captopril, NHE3 was localized to the base of the microvilli and NaPi2 to subapical cytoplasmic vesicles; after 20 min ANG II, both NHE3 and NaPi2 redistributed into the microvilli, assayed by confocal microscopy and density gradient fractionation. Additional PT proteins that redistributed into low-density microvilli-enriched membranes in response to ANG II included myosin VI, DPPIV, NHERF-1, ezrin, megalin, vacuolar H+-ATPase, aminopeptidase N, and clathrin. In summary, in response to 20 min ANG II in the absence of a change in BP or GFR, multiple proteins traffic into the PT brush-border microvilli where they likely contribute to the rapid increase in PT salt and water reabsorption.

Sign in / Sign up

Export Citation Format

Share Document