Impact of pharmaceutical dosage form on stability and dissolution of roxithromycin

Open Medicine ◽  
2010 ◽  
Vol 5 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Michał Ostrowski ◽  
Ewa Wilkowska ◽  
Tomasz Bączek
Keyword(s):  
High Performance ◽  
Bitter Taste ◽  
Immediate Release ◽  
Oral Suspension ◽  
Pharmaceutical Dosage Form ◽  
Dissolution Tests ◽  
Ph Conditions ◽  
Dispersible Tablets ◽  
Enteric Coated

AbstractThe behavior of dispersible tablets containing enteric-coated pellets and oral suspension, both containing roxithromycin, was investigated using dissolution tests in different media. The dissolution test was performed under different pH conditions. For both dosage forms investigated, the test was conducted at pH 1.2, 4.5, and 6.8. Additionally, for dispersible tablets, the test involving increasing pH was performed at pH 1.2 (acid stage) and afterwards at pH 6.8 (buffer stage). The extent of dissolution was measured using high-performance liquid chromatography (HPLC). In all cases tested, roxithromycin underwent rapid degradation at pH 1.2. Dispersible tablets displayed the features of modified release preparations with a non-complete dissolution during the test times in all media. Conversely, the oral suspension behaved as an immediate release preparation, with degradation at pH 1.2. However, the dissolution of the oral suspension at pH 4.5 and 6.8 was rapid and complete. The role of enteric-coated pellets is to mask the bitter taste of the active substance upon administration. However, the coating showed lack of resistance to media at pH 1.2. Therefore, dispersible tablets containing enteric-coated pellets are not pharmaceutically equivalent to the immediate-release oral suspension.

Trace nanoanalysis

1994 ◽  
Vol 52 ◽  
pp. 940-941
Author(s):  
D. E. Newbury ◽  
R. D. Leapman
Keyword(s):  
High Performance ◽  
Secondary Ion Mass Spectrometry ◽  
Detection Efficiency ◽  
Volume Element ◽  
And Performance ◽  
Trace Constituents ◽  
Secondary Ion ◽  
Concentration Levels ◽  
Structure Properties

Trace constituents, which can be very loosely defined as those present at concentration levels below 1 percent, often exert influence on structure, properties, and performance far greater than what might be estimated from their proportion alone. Defining the role of trace constituents in the microstructure, or indeed even determining their location, makes great demands on the available array of microanalytical tools. These demands become increasingly more challenging as the dimensions of the volume element to be probed become smaller. For example, a cubic volume element of silicon with an edge dimension of 1 micrometer contains approximately 5×1010 atoms. High performance secondary ion mass spectrometry (SIMS) can be used to measure trace constituents to levels of hundreds of parts per billion from such a volume element (e. g., detection of at least 100 atoms to give 10% reproducibility with an overall detection efficiency of 1%, considering ionization, transmission, and counting).

Two Short Tests Fail to Detect Vigilance Decrements

2001 ◽  
Vol 17 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Juan Botella ◽  
María José Contreras ◽  
Pei-Chun Shih ◽  
Víctor Rubio
Keyword(s):  
Individual Differences ◽  
High Performance ◽  
Selection Process ◽  
Vigilance Task ◽  
Air Traffic Controllers ◽  
Job Selection ◽  
Performance Deterioration ◽  
Short Test ◽  
Psychological Dimensions

Summary: Deterioration in performance associated with decreased ability to sustain attention may be found in long and tedious task sessions. The necessity for assessing a number of psychological dimensions in a single session often demands “short” tests capable of assessing individual differences in abilities such as vigilance and maintenance of high performance levels. In the present paper two tasks were selected as candidates for playing this role, the Abbreviated Vigilance Task (AVT) by Temple, Warm, Dember, LaGrange and Matthews (1996) and the Continuous Attention Test (CAT) by Tiplady (1992) . However, when applied to a sample of 829 candidates in a job-selection process for air-traffic controllers, neither of them showed discriminative capacity. In a second study, an extended version of the CAT was applied to a similar sample of 667 subjects, but also proved incapable of properly detecting individual differences. In short, at least in a selection context such as that studied here, neither of the tasks appeared appropriate for playing the role of a “short” test for discriminating individual differences in performance deterioration in sustained attention.

Knowledge, Perceptions and Practices on Modified Release Tablets among Prescribers: A Preliminary Study

2020 ◽  
Vol 01 (01) ◽  
pp. 05-14
Author(s):  
M.G.K.M. Fernando ◽  
K.I.J. Priyadarshi ◽  
L.G.T. Shanika ◽  
N.R. Samaranayake
Keyword(s):  
Online Survey ◽  
Product Information ◽  
Response Rate ◽  
Immediate Release ◽  
State Universities ◽  
Modified Release ◽  
Validated Questionnaire ◽  
Therapeutic Outcomes ◽  
Medical Faculties ◽  
Enteric Coated

Introduction: Modified release tablets (MRTs) are developed to achieve different therapeutic outcomes and are frequently prescribed. This study aims to evaluate the knowledge, perceptions and practices on using MRTs among a selected cohort of prescribers. Methods: A self administered online survey was conducted using a pre-validated questionnaire, prepared in-house to assess knowledge, perceptions and practices on using MRTs, among academics with an MBBS degree in medical faculties of State universities in Sri Lanka. Results: The response rate was 15.5% among 375 prescribers. Most were females (53.4%) and were 46-55 years (29.3%). Over 50% correctly expanded abbreviations related to MRTs. Most defined enteric coated (87.9%) and targeted release (77.6%) forms accurately. However, 87.0% mixed-up definitions of sustained release with controlled release. Most believed that inability to split tablets (70.7%) and high cost (70.7%), as disadvantages of MRTs. Nearly half did not identify the risk of dose dumping (53.5%) and inflexible dosing schedule (44.8%) as disadvantages. For frequency of administering MRTs, 86.2% referred the product information leaflet (PIL) while 29.0% depended on the frequency of the corresponding immediate release tablet. Most (79.3%) prescribed MRTs to increase patient compliance while 12.1% prescribed them to reduce cost. When problems regarding MRTs were encountered, most referred PILs (81.0%) and clarified with experts (75.9%). Conclusions: Although the response rate was low, a clear gap in knowledge, perceptions and practices on using MRTs were identified among prescribers who responded. Interventions are needed to improve the knowledge, perceptions, and practices on using MRTs among prescribers.

Enhanced oral bioavailability of Etodolac by liquisolid compact technique: optimisation, in-vitro and in-vivo evaluation

2020 ◽  
Vol 17 ◽  
Author(s):  
Bhumin K. Pathak ◽  
Meenakshi Raghav ◽  
Arti R. Thakkar ◽  
Bhavin A. Vyas ◽  
Pranav J. Shah
Keyword(s):  
Dissolution Rate ◽  
Amorphous State ◽  
Immediate Release ◽  
Angle Of Repose ◽  
Oral Suspension ◽  
Load Factor ◽  
In Vivo Evaluation ◽  
Rate Of Dissolution ◽  
Q 30

Background: Poor dissolution of Etodolac is one of the major challenges in achieving the desired therapeutic effect in oral therapy. Objective: This study aimed to assess the potential of liquisolid compact technique in increasing the rate of dissolution of Etodolac and thus its bioavailability. Methods: Liquisolid compacts were prepared using PEG 400, Avicel PH-200 and Aerosil 200 as non-volatile liquid, carrier and coating material respectively. Optimisation was carried out by applying a 32 full factorial design using Design expert software 11.0.3.0 to examine the effects of independent variables (load factor and carrier: coating ratio) on dependent variables (angle of repose and % cumulative drug release at 30 min [Q 30 min]).Assessment of bioavailability was based on pharmacokinetic study in rabbits and pharmacodynamics evaluation in rats respectively. Results: The formulation M3 was identified as the optimised formulation based on the better flow (lower angle of repose) and a higher rate of dissolution (Q 30 min >95%). The higher dissolution rate could be due to conversion of Etodolac into an amorphous molecularly dispersed state, availability of larger surface area, enhancement of aqueous solubility and enhanced wetting of drug particles. Studies with DSC, XRD, and SEM verified the transformation of Etodolac from crystalline to amorphous state, a key factor responsible for improving the dissolution rate. Pharmacokinetic profile of M3 was prominent, demonstrating higher absorption of Etodolac in comparison of oral suspension and immediate-release conventional tablets in rabbits. Liquisolid formulation exhibited 27% increment in paw thickness as compared to 57% and 46% increments for oral suspension and immediate-release conventional tablets respectively, after 7 hrs in carrageenan-induced paw model in rats. Conclusion: The results indicated liquisolid compact technique to be a promising strategy to enhance the bioavailability of Etodolac.

scholarly journals Functional response of Harmonia axyridis preying on Acyrthosiphon pisum nymphs: the effect of temperature

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yasir Islam ◽  
Farhan Mahmood Shah ◽  
Xu Rubing ◽  
Muhammad Razaq ◽  
Miao Yabo ◽  
...  
Keyword(s):  
Functional Response ◽  
High Performance ◽  
Acyrthosiphon Pisum ◽  
Harmonia Axyridis ◽  
Effect Of Temperature ◽  
Functional Responses ◽  
Aphid Control ◽  
Host Aphid ◽  
Predator Foraging

AbstractIn the current study, we investigated the functional response of Harmonia axyridis adults and larvae foraging on Acyrthosiphon pisum nymphs at temperatures between 15 and 35 °C. Logistic regression and Roger’s random predator models were employed to determine the type and parameters of the functional response. Harmonia axyridis larvae and adults exhibited Type II functional responses to A. pisum, and warming increased both the predation activity and host aphid control mortality. Female and 4th instar H. axyridis consumed the most aphids. For fourth instar larvae and female H. axyridis adults, the successful attack rates were 0.23 ± 0.014 h−1 and 0.25 ± 0.015 h−1; the handling times were 0.13 ± 0.005 h and 0.16 ± 0.004 h; and the estimated maximum predation rates were 181.28 ± 14.54 and 153.85 ± 4.06, respectively. These findings accentuate the high performance of 4th instar and female H. axyridis and the role of temperature in their efficiency. Further, we discussed such temperature-driven shifts in predation and prey mortality concerning prey-predator foraging interactions towards biological control.

Revealing the role of dopants in mitigating degradation phenomena in sodium-ion layered cathodes

2021 ◽  
Vol 23 (3) ◽  
pp. 2038-2045
Author(s):  
Kyoungmin Min ◽  
Young-Han Shin
Keyword(s):  
Cathode Materials ◽  
High Performance ◽  
High Stability ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
Layered Cathode Materials ◽  
Layered Cathodes

Prevention of the degradation of sodium-based layered cathode materials is the key to developing high-performance and high-stability sodium-ion batteries.

scholarly journals Towards a Glass New World: The Role of Ion-Exchange in Modern Technology

2021 ◽  
Vol 11 (10) ◽  
pp. 4610
Author(s):  
Simone Berneschi ◽  
Giancarlo C. Righini ◽  
Stefano Pelli
Keyword(s):  
Ion Exchange ◽  
Communication Networks ◽  
High Speed ◽  
High Performance ◽  
Low Cost ◽  
Modern Technology ◽  
Historical Background ◽  
Wide Range ◽  
Happy Marriage

Glasses, in their different forms and compositions, have special properties that are not found in other materials. The combination of transparency and hardness at room temperature, combined with a suitable mechanical strength and excellent chemical durability, makes this material indispensable for many applications in different technological fields (as, for instance, the optical fibres which constitute the physical carrier for high-speed communication networks as well as the transducer for a wide range of high-performance sensors). For its part, ion-exchange from molten salts is a well-established, low-cost technology capable of modifying the chemical-physical properties of glass. The synergy between ion-exchange and glass has always been a happy marriage, from its ancient historical background for the realisation of wonderful artefacts, to the discovery of novel and fascinating solutions for modern technology (e.g., integrated optics). Getting inspiration from some hot topics related to the application context of this technique, the goal of this critical review is to show how ion-exchange in glass, far from being an obsolete process, can still have an important impact in everyday life, both at a merely commercial level as well as at that of frontier research.

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