Preparation and Characterization of Controlled-Release Floating Bilayer Tablets of Esomeprazole and Clarithromycin.

Controlled-release effervescent floating bilayer tablets reduce dosage frequency and improve patient compliance with enhanced therapeutic outcomes. Generally, two different tablets of clarithromycin and esomeprazole, respectively, are given for the treatment of Helicobacter pylori infection and it might be worth incorporating both in a single tablet. In the current study, controlled-release floating bilayer tablets of clarithromycin and esomeprazole (F1−F4) were developed with different rates of polymeric materials by a direct compression method. During the formulation, Fourier-transform infrared spectroscopy (FTIR) analysis was performed for possible interactions between drugs and excipients. No interactions between drugs and excipients were noted. Moreover, the bilayer tablets' thickness, diameter, friability, hardness, weight variation, dissolution, and percent purity were found within the acceptable limits. The floating lag time and total floating time of all formulations were found to be < 25 s and 24 h, respectively. The release of both the clarithromycin and esomeprazole started at the same time from the controlled-release floating bilayer tablets by anomalous non-Fickian diffusion, and the polymeric materials extended the drug release rate up to 24 h. In the case of F1, the results approached ideal zero-order kinetics. The dissolution profiles of the tested and reference tablet formulations were compared, but no significant differences were observed. It can be concluded that such controlled-release effervescent floating bilayer tablets can be efficiently used in clinical practice to reduce dosage frequency and increase patient compliance with continuous drug release for 24 h, which ultimately might enhance therapeutic efficacy.

Preparation of Losartan Potassium Controlled Release Matrices and In-Vitro Investigation Using Rate Controlling Agents.

Controlled release matrices have predictable drug release kinetics, provide drugs for an extended period of time, and reduce dosing frequency with improved patient compliance as compared with conventional tablet dosage forms. In the current research work, losartan potassium controlled release matrix tablets were fabricated and prepared with rate altering agents; that is, Ethocel grade 100 combined with Carbopol 934PNF. Various drug to polymer ratios were used. HPMC, CMC, and starch were incorporated in some of the matrices by replacing some amount of filler (5%). The direct compression method was adopted for the preparation of matrices. In phosphate buffer (pH 6.8), the dissolution study was conducted by adopting the USP method-I as the specified method. Drug release kinetics was determined and dissolution profiles were also compared with the reference standard. Prolonged release was observed for all matrices, but those with Ethocel 100FP Premium showed more extended release. The co-excipient (HPMC, CMC, and starch) exhibited enhancement in the drug release rates, while all controlled release matrices released the drug by anamolous non-Fickian diffusion mechanism. This combination of polymers (Ethocel grade 100 with Carbopol 934PNF) efficiently extended the drug release rates up to 24 h. It is suggested that these matrix tablets can be given in once a day dosage, which might improve patient compliance, and the polymeric blend of Ethocel grade 100 with Carbopol 934PNF might be used in the development of prolonged release matrices of other water-soluble drugs.

Design, Preparation and evaluation of various parameters of controlled release matrices of losartan potassium using polymers combination.

Controlled release formulations are administered once a day and reduce frequency of dose and ensuring patient's compliance. In the current research controlled release matrices of losartan potassium formulated with polymeric combinations of ethocel grade 7 with carbopol 934P NF using different concentrations of polymers. In some polymeric tablets, Co-excipients like CMC, Starch, HPMC was added by replacing of 10% of filler in formulations at 10:5. Tablets were prepared by direct compression method and evaluated for physicochemical characteristics. USP Method-1 (rotating basket method) was used to carry out dissolution study in phosphate buffer pH 6.8. Drug release kinetics determined and comparison of dissolution patterns was done with reference tablets. The polymeric combinations well retarded drug release and drug was released by anamolous non-fickian diffusion mechanism. Dissolution profiles of tested tablets and reference tablets were found not similar. Drug release rate was increased by co-excipients. It was concluded from this research work that this polymeric combination can be used efficiently in designing of controlled release martices.

Thiol-disulfide exchange reactions occurring at modified bovine serum albumin detected using ellman's reagent (5, 5'-dithiobis (2-itrobenzoic acid).

Bovine serum albumin (BSA) is usually employed as a model protein because of being homologous with human serum albumin. Cysteine-34 of BSA has been oxidised with Ellman's reagent to produce BSA labelled with an Ellman's moiety (BSA-SE). The BSA-SE was then reacted with glutathione, N-acetylcysteine and D-penicillamine (D-pen). The two were able to release the Ellman's moiety bound at cysteine-34 while D-pen did not. Albumin labeled using Ellman's reagent was used to demonstrate the cleavage of a protein mixed disulphide. The kinetics of thiol disulfide interchange reactions involving formation of a chromophoric thiolate were determined by UV-visible spectroscopy. The reaction of thiolates with excess Ellman's reagent is used for quantitative estimation of thiol by measuring the absorption at λ, 412 nm. The disulfide exchange reactions occurring at Cys-34 of BSA was determined and the reduction of oxidized Cys-34 was studied in order to understand the reverse reaction. Spectroscopic evidence suggested that glutathione and N-acetylcysteine remove the label and produce BSA in a disulfide form. In contrast, D-pen reaction returned BSA to its thiolate form via mediation. It was observed that thio-disulfide exchange occurred at cysteine-34 labelled with Ellman's moiety. The implications to the redox status of plasma are discussed.

Systematic review of economic evaluations of exercise and physiotherapy for patients treated for breast cancer.

PURPOSE: Treatments for breast cancer can lead to chronic musculoskeletal problems. This study aimed to systematically review the evidence surrounding the cost-effectiveness of exercise and physiotherapy interventions aimed at reducing the risk of physical symptoms and functional limitations due to breast cancer treatment. METHODS: A systematic review of the cost-effectiveness of exercise and physiotherapy interventions during and following treatment for breast cancer was undertaken according to PRISMA guidelines. Literature searches were carried out in Ovid MEDLINE, Ovid Embase, Web of Science, EconLit, CINAHL, PsycINFO, Scopus and the Cochrane Library. Cost-effectiveness evidence was summarised in a descriptive manner and studies were assessed using quality appraisal tools. The review protocol was registered on PROSPERO. RESULTS: A total of 7783 articles were identified and seven were included in the final review. Five studies undertook trial-based economic evaluations, whereas two studies conducted economic evaluation based on decision models. One study was a cost-effectiveness analysis (CEA), three undertook stand-alone cost-utility analyses (CUA) and three studies were combined CEAs and CUAs. Three studies reported favourable cost-effectiveness results for different exercise or physiotherapy interventions. In contrast, four studies found that exercise and physiotherapy interventions were not cost-effective on the basis of quality-adjusted life year outcomes. CONCLUSIONS: The evidence surrounding the cost-effectiveness of exercise and physiotherapy interventions for the treatment of breast cancer remains sparse with contrasting conclusions. Future research should particularly aim to broaden the evidence base by disentangling the contributing effects of frequency, intensity, time and type of exercise and physiotherapy interventions on cost-effectiveness outcomes.

Formulation and in vitro evaluation of directly compressed controlled release tablets designed from the Co-precipitates.

Controlled release dosage forms provide sustained therapeutics effects for prolonged period of time and improve patient compliance. In present study, controlled release co-precipitates of Metoprolol Tartrate and Losartan Potassium were prepared by solvent evaporation method using polymers such as Eudragit RL 100 and Carbopol 974PNF and controlled release tablets were directly compressed into tablets. In-vitro dissolution of controlled release co-precipitates were performed by USP Method-II (paddle method) and tablets were evaluated by USP Method-I (rotating basket method) in phosphate buffer (PH 6.8) using pharma test dissolution apparatus. The temperature was maintained constant at 37±1.0°C and the rotation speed of paddle and basket was kept constant at 100rpm. Drug release mechanisms were determined by applying Power Law kinetic model. The difference and similarity of dissolution profiles test formulations with reference standards were also determined by applying difference factor (f1) and similarity factor (f2). The results showed that the controlled release co-precipitates with polymer Eudragit RL 100 of both the drug extended the drug release rates for 10 hours and those having polymer Carbopol 974P NF extended the drug release rates for 12 hours. The controlled release tablets prepared from controlled release co-precipitates extended the drugs release up to 24 hours with both the polymers. The drug was released by all tests anomalous non fickian mechanism except F1 and F5 do not follow Power Law. The f1 and f2 values obtained were not in acceptable limits except F15 whose values were in acceptable limits. It is concluded from the present study that polymers (Eudragit RL 100 and Carbopol 974P NF) can be efficiently used in development of controlled release dosage forms having predictable kinetics.

FORMULATION, EVALUATION AND IN VITRO DISSOLUTION PERFORMANCE OF ENALAPRIL MALEATE SUSTAINED RELEASE MATRICES: EFFECT OF POLYMER COMPOSITION AND VISCOSITY GRADE.

The present study aimed at developing the sustained release matrix tablets of enalapril maleate and evaluating the effect of polymer concentration and viscosity grade on drug release. The sustained release enalapril maleate tablets were successfully formulated by direct compression method using nonionic cellulose ethers HPMC K15, HPMC K100 and HPC polymers either alone or in combination. In-vitio drug release study was carried out in phosphate buffer (pH 6.8) for a period of 24 h following USP dissolution apparatus II i.e., paddle apparatus. Model dependent approaches like zero-order, first order, Higuchi's model and Korsmeyer-Peppas model were used to assess drug release from various formulations. All the three polymers alone or in combination sustained the drug release. The drug release characteristics from HPMC and HPC polymer followed zero order release kinetics except for 45% concentration of all polymers alone or in combination where by the drug release followed Higuchi's model. In all cases, the drug release mechanism was both diffusion as well as erosion.

Controlled release matrix tablets of glipizide: Influence of different grades of ethocel and Co-excipient on drug release.

The aim of the current study was to formulate and evaluate glipizide controlled release matrix tablets by means of different grades of polymer Ethoceland different co-excipients in order to evaluate their effect on drug release profiles during in vitro dissolution studies. Type II diabetes mellitus is usually treated with Glipizide. Glipizide belongs to sulfonylurea group. Gastric disturbance and severe hypoglycemia has been observed after taking glipizide orally. To overcome these problems, controlled release matrices were developed using different grades of ethyl cellulose polymer with a drug-polymer ratio of 1:3by the direct compression method. The effect on drug release of partial replacement of lactose by different co-excipients, HPMC K100M, starch and CMC, were also studied. Diameter, thickness, hardness, friability, weight variations, drug contents of formulations were tested, these properties were within prescribed limits. Co-excipients and polymer containing formulations were compared to the without co-excipients and polymer containing formulations with respect to their release profile. After a 24-hour release study, ethyl cellulose polymer containing formulation exhibited prolonged release for 5-16 hours; however the polymer Ethocel (R) standard FP 7 Premium without co-excipient containing formulation exhibited controlled release for 24 hours. Incompatibility was investigated between drugs, co-excipient DSC and polymer study was performed and any type of interaction was not found. Different kinetic models were used to study the release mechanism. An enhanced release rate was observed in case of excipients containing formulations.

To study the influence of different grades of Ethylcellulose ether derivative polymer Ethocel® and co-excipient on drug release profile of controlled release matrix tablet of acarbose.

The aim of the study presented is to formulate and evaluate Acarbose controlled release matrix tablets by means of different grades of polymer Ethocel and different co-excipients with the intention to see their effects on drug release profile during in vitro dissolution studies. Controlled release dosage forms is gaining rapid popularity due to its positive aspect of reduction in dosage frequency and curtailing side effects. Controlled released tablets of Acarbose were prepared by direct compression method, using Ethocel® Standard 7 Premium and Ethocel® Standard 7 FP premium polymer. The effect of co-excipients including hydroxypropyl methylcellulose (HPMC), Carboxymethyl cellulose (CMC) and starch on the drug placing 30% lactose were also examined. In-vitro studies were carried out with the help of phosphate buffer (pH 7.4) as dissolution medium. Drug release mechanism was assessed by applying various kinetic models. Similarly / dissimilarity factor f2/ f1 were applied for determination of dissolution profile of the test and reference formulations. Physiochemical characteristics were in the USP satisfactory limits. Conventional Acarbose tablet released 97% of the drug within 2 hrs. Ethocel® Standard 7 premium and Ethocel® standard 7 FP released 59.9% and 47.01% of the drug within 6 and 99.9% and 97% within 24 hours, respectively. This effect possibly has been achieved owing to the smaller particle size of the Ethocel® Standard 7 FP premium which show evidence of anomalous, non-fickian release kinetics. Co-excipients like HPMC, CMC and starch augment the drug release rates from the matrices which may be attributed to their hydrophilic nature. Ethocel® Standard 7 Premium and Ethocel® Standard premium 7 FP polymers show a promising response in fruitful production of controlled release tablets by direct compression method.

Formulation and Preparation of Losartan-Potassium-Loaded Controlled-Release Matrices Using Ethocel Grade 10 to Establish a Correlation between In Vitro and In Vivo Results.

In the current study, matrices of losartan potassium were formulated with two different polymers (Ethocel 10 premium and Ethocel 10FP premium), along with a filler and a lubricant, at different drug-to-polymer w/w ratios (10:3, 10:4, and 10:5). The matrices were tested by the direct compression method, and their hardness, diameter, thickness, friability, weight variation, content uniformity, and in vitro dissolution tests were assessed to determine 24-h drug release rates. The matrices with Ethocel 10 FP at a 10:4 ratio exhibited pseudo-zero-order kinetics (n-value of 0.986), while the dissolution data of the test matrices and reference tablets did not match. The new test-optimized matrices were also tested in rabbits, and their pharmacokinetic parameters were investigated: half-life (11.78 ± 0.018 h), Tmax (2.105 ± 1.131 h), Cmax (205.98 ± 0.321 µg/mL), AUCo (5931.10 ± 1.232 µg·h/mL), AUCo-inf (7348.46 ± 0.234 µg·h/mL), MRTo-48h (17.34 ± 0.184 h), and Cl (0.002 ± 0.134 mL/min). A correlation value of 0.985 between the in vitro and in vivo results observed for the test-optimized matrices was observed, indicating a level-A correlation between the percentage of the drug released in vitro and the percentage of the drug absorbed in vivo. The matrices might improve patient compliance with once-a-day dosing and therapeutic outcomes.

Preparation and In Vitro Evaluation of Levofloxacin-Loaded Floating Tables Using Various Rate-Controlling Agents.

Floating tablets are a new approach to extending the time a drug is in the stomach to improve therapy outcomes. Floating tablets were formulated with the drug, the polymers hydroxypropyl methylcellulose (HPMC), carboxymethyl cellulose (CMC), and starch, fillers, and lubricants. The tablets were prepared using the direction compression method. The tablets' physical quality control tests were found to be within acceptable limits. The tablets extended drug release up to 12 h and were uniform in their drug contents. The swelling index of the tablets ranged from 60 ± 0.11 to 66 ± 0.14%, and the tablets were less dense than water. The floating lag time (10 ± 0.23 to 16 ± 0.09 s) and total floating time (>12 h) showed good floating behaviors. The kinetic modeling showed that the drug was released from the tablets by pseudo-diffusion, swelling, erosion, or anomalous non-Fickian diffusion. F6 (starch and CMC) showed higher n values (0.994 ± 0.04), exhibiting pseudo-zero-order drug release kinetics compared to those of other tablets. The dissolution data of the test and reference tables were not similar (P > 0.05). In terms of antimicrobial activity, the zones of inhibition of the test F6 tablet powders (5.3 ± 0.08 mm) and the reference tablet powders (5.9 ± 0.13 mm) were found to be significantly similar (P > 0.05). The study concluded that these floating tablets can improve the gastric residence time and therapeutic outcomes.

Development of novel diclofenac potassium controlled release tablets by wet granulation technique and the effect of co-excipients on in vitro drug release rates.

The aim of the present study was the formulation and evaluation of controlled release polymeric tablets of Diclofenac Potassium by wet granulation method for the release rate, release pattern and the mechanism involved in drug release. Formulations having three grades of polymer Ethocel (7P; 7FP, 10P, 10FP, 100P, 100FP) in several drugs to polymer ratios (10:3 and 10:1) were compressed into tablets using wet granulation method. Co-excipients were added to some selected formulations to investigate their enhancement effect on in vitro drug release patterns. In vitro drug release studies were performed using USP Method-1 (Rotating Basket method) and Phosphate buffer (pH 7.4) was used as a dissolution medium. The similarities and dissimilarities of release profiles of test formulations with reference standard were checked using f2 similarity factor and f1 dissimilarity factor. Mathematical/Kinetic models were employed to determine the release mechanism and drug release kinetics.

Preparation and In Vitro Evaluation of Controlled-Release Matrices of Losartan Potassium Using Ethocel Grade 10 and Carbopol 934P NF as Rate-Controlling Polymers.

Controlled-release formulations are essential for those drugs that require fine tuning of their activity to increase the ratio between therapeutic vs. adverse effects. Losartan potassium is among those drugs whose adverse effects may somehow impair its purported benefits. Previous investigations have been carried out to ascertain the suitability of several polymers for being associated with losartan. This study is focused on the effects of Ethocel grade 10 and Carbopol 934P NF on losartan release. Flow and physical properties were assessed according to the protocols standardized by the pharmacopeia (USP-NF 29), and the drug release in phosphate buffer (pH = 6.8) was measured for 24 h. Data evidenced good to excellent flow and physical properties according to the drug/polymer ratio and the addition of co-excipients. The release rate in 24 h was found to be 63-69% to 79-82% without or with the addition of co-excipients, respectively, following zero-order kinetics. The results also suggest a significant difference with the release profile of a traditional release losartan formulation. The results suggest the suitability of Ethocel grade 10 and Carbopol 934P NF as components of a controlled-release losartan formulation.

Tacrolimus-Loaded Solid Lipid Nanoparticle Gel: Formulation Development and In Vitro Assessment for Topical Applications.

The currently available topical formulations of tacrolimus have minimal and variable absorption, elevated mean disposition half-life, and skin irritation effects resulting in patient noncompliance. In our study, we fabricated tacrolimus-loaded solid lipid nanoparticles (SLNs) that were converted into a gel for improved topical applications. The SLNs were prepared using a solvent evaporation method and characterized for their physicochemical properties. The particle size of the SLNs was in the range of 439 nm to 669 nm with a PDI of ≤0.4, indicating a monodispersed system. The Zeta potential of uncoated SLNs (F1-F5) ranged from -25.80 to -15.40 mV. Those values reverted to positive values for chitosan-decorated formulation (F6). The drug content and entrapment efficiency ranged between 0.86 ± 0.03 and 0.91 ± 0.03 mg/mL and 68.95 ± 0.03 and 83.68 ± 0.04%, respectively. The pH values of 5.45 to 5.53 depict their compatibility for skin application. The surface tension of the SLNs decreased with increasing surfactant concentration that could increase the adherence of the SLNs to the skin. The release of drug from gel formulations was significantly retarded in comparison to their corresponding SLN counterparts (p ≤ 0.05). Both SLNs and their corresponding gel achieved the same level of drug permeation, but the retention of the drug was significantly improved with the conversion of SLNs into their corresponding gel formulation (p ≤ 0.05) due to its higher bioadhesive properties.

Synthesis, Characterization and In Vitro Evaluation of Chitosan Nanoparticles Physically Admixed with Lactose Microspheres for Pulmonary Delivery of Montelukast.

This study aimed to synthesise montelukast-loaded polymeric nanoparticles via the ionic gelation method using chitosan as a natural polymer and tripolyphosphate as a crosslinking agent. Tween 80, hyaluronic acid and leucine were added to modify the physicochemical properties of nanoparticles, reduce the nanoparticles' uptake by alveolar macrophages and improve powder aerosolisation, respectively. The nanoparticles ranged from 220 nm to 383 nm with a polydispersity index of ≤0.50. The zeta potential of nanoparticles ranged from 11 mV to 22 mV, with a drug association efficiency of 46-86%. The simple chitosan nanoparticles (F2) were more spherical in comparison to other formulations (F4-F6), while the roughness of hyaluronic acid (F5) and leucine (F6) added formulations was significantly high er than F2 and Tween 80 added formulation (F4). The DSC and FTIR analysis depict that the physical and chemical properties of the drug were preserved. The release of the drugs from nanoparticles was more sustained in the case of F5 and F6 when compared to F2 and F4 due to the additional coating of hyaluronic acid and leucine. The nanoparticles were amorphous and cohesive and prone to exhalation due to their small size. Therefore, nanoparticles were admixed with lactose microspheres to reduce particle agglomeration and improve powder dispersion from a dry powder inhaler (DPI). The DPI formulations achieved a dispersed fraction of 75 to 90%, a mass median aerodynamic diameter (MMAD) of 1-2 µm and a fine particle fraction (FPF) of 28-83% when evaluated using the Anderson cascade impactor from Handihaler®. Overall, the montelukast-loaded nanoparticles physically admixed with lactose microspheres achieved optimum deposition in the deep lung for potential application in asthmatic patients.

Effect of lithium metal on the chemical status of glutathione (GSH) present in whole blood (especially in plasma and cytosolic fraction in human blood).

Lithium remains a mainstay in the acute and prophylactic treatment of bipolar affective disorder. It is used in the augmentation of antidepressant treatment and, less frequently, in the augmentation of antipsychotic treatment of schizophrenia. It is reported to have specific anti-suicidal effects. Thus the effect of Lithium was interesting to study on the glutathione (GSH) level in vivo conditions. Ellman's method has been used to see the effect of lithium on glutathione (GSH) level in whole blood. The time dependent effect of Lithium on the chemical status of glutathione (GSH) was determined in the whole blood (Plasma and cytosolic fraction) of human. The concentration of Glutathione was drastically decreased. The decrease in the glutathione level was concentration and time of interaction dependent, probably due to oxidation of glutathione (GSH) to corresponding disulphide (GSSG). In this paper the effect of Lithium on the Thiol/GSH level was discussed in vitro, which in principal may present a model of in vivo reaction.

Preferences for portable ultrasound devices: a discrete choice experiment among abdominal aortic aneurysm surveillance patients and general ultrasound patients in England.

OBJECTIVE: To undertake an assessment of preferences as to how, where and by whom ultrasounds (US) should be performed in: (1) patients undergoing surveillance of abdominal aortic aneurysm (AAA) size (AAA group); and (2) patients being scanned for general abdominal conditions (general group). DESIGN: A discrete choice experiment (DCE) questionnaire was administered to patients attending US appointments. Analysis of questionnaire responses used conditional logit models and included validity checks. SETTING: West Midlands, England. PARTICIPANTS: 524 patients (223 in the AAA group and 301 in the general group) were recruited from the US outpatient department at University Hospital Coventry and Warwickshire. OUTCOME MEASURES: Coefficients for attributes in relation to their reference levels. RESULTS: The AAA group preferred to have their US performed in hospital while the general group had a preference for portable US at general practice surgeries. All patients had a strong preference for scanning by specialists, devices with a lower risk of underdiagnosis and receiving their results at the appointment where the scan takes place. The general group had a strong preference for the person performing the scan to know their medical history. CONCLUSIONS: Patients being scanned for general abdominal conditions prefer to be scanned in a general practice by practitioners who know their medical history. Patients undergoing surveillance of AAA size prefer to be scanned in a hospital setting. Both groups would prefer to be informed of the scan results as soon as possible. Further research is required to explore the clinical scenarios in which targeted scanning by community practitioners would be of benefit to patients.

Formulation and in-vitro evaluation of directly compressed controlled release matrices of Losartan Potassium using Ethocel Grade 100 as rate retarding agent.

Current study was aimed to develop 200mg controlled release matrix tablets of Losartan Potassium using Ethocel 100 Premium and Ethocel 100 FP Premium as rate controlling polymer. In-vitro studies were performed according to USP Method-I in phosphate buffer (PH 6.8) using pharma test dissolution apparatus. The temperature of the dissolution medium was kept constant at 37±0.5°C at 100rpm. Flow properties, physical quality control tests, effect of polymer size and drug-to-polymers ratios were studied using different kinetics models such as 1st-order, zero-order, Hixon Crowell model, Highuchi model and Power law. Difference factor f1 and similarity factor f2 were applied for dissolution profiles against Cardaktin® tablets used as a reference formulation. The matrices with polymer ethocel 100 FP Premiums have prolonged the drug release rate as compared to polymer ethocel 100 Premiums. The n values matrices with polymer ethocel grade 100 ranged from 0.603 to 0.857 indicating that the drug release occurred by anomalous non fickian diffusion kinetics while then value of reference Cardaktin® tablet was measured as 0.125 indicating that these tablets do not follow power law. The dissolution profiles of test formulations were different than that of reference Cardaktin®. This suggests the polymer Ethocel grade 100 can be proficiently incorporated in fabrication and development of once a day controlled release matrix tablets.