An in vivo and in silico evaluation of the hepatoprotective potential of Gynura procumbens: A promising agent for combating hepatotoxicity.

INTRODUCTION: The liver, the most important metabolic organ of the body, performs a wide variety of vital functions. Hepatic cell injury occurs by the activation of reactive oxygen species (ROS) that are generated by carbon tetrachloride (CCl4), xenobiotics, and other toxic substances through cytochrome P450-dependent steps resulting from the covalent bond formation with lipoproteins and nucleic acids. Observing the urgent state of hepatotoxic patients worldwide, different medicinal plants and their properties can be explored to combat such free radical damage to the liver. In vivo and in silico studies were designed and conducted to evaluate the antioxidant and hepatoprotective properties of Gynura procumbens in rats. MATERIALS AND METHODS: Gynura procumbens leaves were collected and extracted using 70% ethanol. The required chemicals CCl4, standard drug (silymarin), and blood serum analysis kits were stocked. The in vivo tests were performed in 140 healthy Wister albino rats of either sex under well-controlled parameters divided into 14 groups, strictly maintaining Institutional Animal Ethics Committee (IEAC) protocols. For the histopathology study, 10% buffered neutral formalin was used for organ preservation. Later the specimens were studied under a fluorescence microscope. In silico molecular docking and absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies were performed, and the results were analyzed statistically. RESULTS AND DISCUSSION: Gynura procumbens partially negate the deleterious effect of carbon tetrachloride on normal weight gain in rats. The elevated level of serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT), alkaline phosphatase (ALP), creatinine, LDH, total cholesterol (TC), low-density lipoprotein (LDL), triglycerides (TG), malondialdehyde (MDA), deoxyribonucleic acid (DNA) fragmentation ranges, gamma-glutamyl transferase (γ-GT) in CCl4 treated groups were decreased by both standard drug silymarin and G. procumbens leaf extract. We have found significant & highly significant changes statistically for different doses, here p<0.05 & p<0.01, respectively. On the other hand, G. procumbens and silymarin displayed Statistically significant (p<0.05) and high significant(p<0.01) increased levels of HDL, CAT SOD (here p<0.05 & p<0.01 for different doses) when the treatment groups were compared with the disease control group. Because the therapeutic activity imparted by plants and drugs accelerates the movement of the disturbed pathophysiological state toward the healthy state. In the molecular docking analysis, G. procumbens phytoconstituents performed poorly against transforming growth factor-beta 1 (TGF-ß1) compared to the control drug silymarin. In contrast, 26 phytoconstituents scored better than the control bezafibrate against peroxisome proliferator-activated receptor alpha (PPAR-α). The top scoring compounds for both macromolecules were observed to form stable complexes in the molecular dynamics simulations. Flavonoids and phenolic compounds performed better than other constituents in providing hepatoprotective activity. It can, thus, be inferred that the extract of G. procumbens showed good hepatoprotective properties in rats.

Modification of Bulk Density, Flow Property and Crystallinity of Microcrystalline Cellulose Prepared from Waste Cotton.

The most affordable type of tablet is the immediately compressible tablet, which uses microcrystalline cellulose (MCC), a popular pharmaceutical excipient, as a filler or binder. To make it compatible with different active drugs and excipients, we tried to change some physical properties of the MCC. In the current study, we used a chelating agent to pretreat the waste cotton before pulping, bleaching, and finally, hydrochloric acid degradation with a concentration of 2N at 100 °C temperature for 20 min to prepare MCC. The prepared MCC was treated with different concentrations of sodium hydroxide at room temperature or at -20 °C followed by precipitation with hydrochloric acid or ethanol with complete washing with distilled water till neutralization. Evaluation of the degree of polymerization (DP) and FT-IR spectrum confirm the identity of the microcrystalline cellulose. The DP was found to be 216. The bulk density of the unmodified MCC was 0.21 while that of modified MCC varied from 0.253 to 0.594. The modified MCC powder showed good flow properties compared to the unmodified MCC as evaluated by the Hausner index, Carr's index and the angle of repose. The scanning electron microscopy (SEM) of the MCC revealed that the rod shape has been changed to an oval shape due to treatment with sodium hydroxide at -20 °C. The X-ray crystallographic (XRD) analysis indicated that the unmodified MCC and standard MCC showed the crystallinity index (CrI) value of 86.82% and 87.63%, respectively, while the value ranges from 80.18% to 60.7% among the modified MCC powder. The differences in properties of the MCC might be due to the variation of rearrangement of the cellulose chain among the MCC particles due to treatment with different concentrations of a base at different temperatures and precipitation environments. This has enabled us to prepare MCC with different properties which might be compatible with different drugs.

Morphological, Spectroscopic and Thermal Analysis of Cellulose Nanocrystals Extracted from Waste Jute Fiber by Acid Hydrolysis.

Natural cellulose, a sustainable bioresource, is highly abundant in nature. Cellulosic materials, particularly those that explore and employ such materials for industrial use, have recently attracted significant global attention in the field of material science because of the unique properties of cellulose. The hydroxyl groups enable the formation of intra- and inter-molecular hydrogen bonding and the arrangement of cellulose chains in a highly ordered crystalline zone, with the remaining disordered structure referred to as an amorphous region. The crystalline areas of cellulose are well-known as cellulose nanocrystals (CNCs). In the present study, we extracted CNCs from pure cellulose isolated from waste jute fibers by sulfuric acid hydrolysis, followed by characterization. Pure cellulose was isolated from jute fibers by treating with sodium hydroxide (20% w/w) and anthraquinone (0.5%) solution at 170 °C for 2 h, followed by bleaching with chlorine dioxide and hydrogen peroxide solution. CNCs were isolated from pure cellulose by treating with different concentrations (58% to 62%) of sulfuric acid at different time intervals (20 min to 45 min). The FTIR study of the CNCs reveals no peak at 1738 cm-1, which confirms the absence of hemicellulose in the samples. The CNCs obtained after 45 min of acid hydrolysis are rod-shaped, having an average length of 800 ± 100 nm and width of 55 ± 10 nm, with a high crystallinity index (90%). Zeta potential significantly increased due to the attachment of SO42- ions on the surface of CNC from -1.0 mV to about -30 mV, with the increment of the reaction time from 20 min to 45 min, which proved the higher stability of CNC suspension. Crystallinity increased from 80% to 90% when the reaction time was increased from 20 to 45 min, respectively, while a crystallite size from 2.705 to 4.56 nm was obtained with an increment of the acid concentration. Acid hydrolysis enhanced crystallinity but attenuated the temperature corresponding to major decomposition (Tmax) at 260 °C and the beginning of degradation (Ti) at 200 °C due to the attachment of SO42- ions on the surface, which decreased the thermal stability of CNC. The second degradation at 360 °C indicated the stable crystal structure of CNC. The endothermic peak at 255 °C in the DTA study provided evidence of sulfated nanocrystal decomposition and the recrystallization of cellulose I to cellulose II, the most stable structure among the other four celluloses. The proposed easy-to-reproduce method can successfully and efficiently produce CNCs from waste jute fibers in a straightforward way.

A Retrospective Evaluation of Self-Reported Adverse Events Following Immunization with Different COVID-19 Vaccines in Türkiye.

BACKGROUND: The Sinovac and BioNTech vaccines were the first to be introduced in Türkiye to fight the ongoing global COVID-19 pandemic. As these vaccines had shown some side-effects in its clinical trial, we aimed to conduct a survey study to assess the short-term adverse events following immunization (AEFIs) in Türkiye. METHOD: A cross-sectional study was conducted using social and electronic media platforms by delivering a pre-formed and validated online questionnaire among people who had received at least one dose of the COVID-19 vaccine. This survey study focused on mass populations from different regions in Türkiye. A total of 603 responses were collected. Among these, 602 were selected based on complete answers and used for the assessment. The collected data were then analyzed to evaluate the various parameters related to the AEFIs of the respondents. RESULTS: Among the total 602 participants, 20.8% were male, and 78.7% were female, actively answering all of the constructive questions. Most of the respondents were between 18-30 years of age. We found that a total of 23.3% of the total respondents had been infected with the SARS-CoV-2 virus. Our survey revealed that out of 602 volunteers, the rate of experiencing physical discomfort was higher in participants who had received the Pfizer-BioNTech vaccine at all three doses than in those who had received the Sinovac vaccine. When all vaccine types were examined, the most common side effect was pain at the injection site, reported by 75.19% participants. When the side effects were compared according to vaccine types, there was a significant difference only in terms of fever. Fever rates in those who had received the Pfizer-BioNTech vaccine (20.96%) were found to be significantly higher than those who had received the Sinovac vaccine (8%). CONCLUSIONS: The studied vaccines showed minor side effects and there was no significant difference between the vaccines in terms of other side effects. Moreover, further research is needed to determine the efficacy of the existing vaccines in preventing SARS-CoV-2 infections or after-infection hospitalization.

Assessing the Self-reported After Events Following Immunization of COVID-19 Vaccines in Turkey and Bangladesh.

Though mass vaccination programs helped to reduce the severity of the ongoing pandemic, various unwanted effects were reported in Turkey and Bangladesh after taking vaccines. The purpose of this study was to evaluate and compare the adverse effects of several vaccines in Turkey and Bangladesh and how the population of both countries prioritizes the continuation of vaccination compared to the side effects. An online survey with a pretest was conducted to gather data over the research period from July 10, 2021 to December 10, 2021. Finally, the questionnaire was shared with the mass population of Turkey and Bangladesh who have received at least one or two doses of the COVID-19 vaccines. The quality of the questionnaire was evaluated with Cronbach's alpha test. The study consisted of 1508 respondents from Bangladesh and 602 respondents from Turkey. Among the total 2110 respondents, 50.0% were male 66.8% were from the 18-30 years age range, and 77.5% reported living in the city area. Among all the respondents, 64.99% of those vaccinated in Bangladesh and 67.28% of those vaccinated in Turkey reported side effects after vaccinations. Participants receiving mRNA vaccines (Pfizer and Moderna) experienced the most side effects, with many reporting pain at the injection site in both nations. Following that, fever, body pain, and headache were common in Bangladesh, whereas body pain, fatigue, and arm numbness were common in Turkey. The study found no significant adverse events reported in Turkey and Bangladesh following the first and second doses of COVID-19 vaccination. These COVID-19 vaccines showed similar patterns of efficacy and safety during the short period of analysis. Vaccines from different manufacturers showed a non-significant level of adverse events during this binational AEFI approach to COVID-19 vaccines. More studies are recommended on the efficacy and safety of several vaccines to discover unexpected effects.

Exploration of Site-Specific Drug Targeting-A Review on EPR-, Stimuli-, Chemical-, and Receptor-Based Approaches as Potential Drug Targeting Methods in Cancer Treatment.

Cancer has been one of the most dominant causes of mortality globally over the last few decades. In cancer treatment, the selective targeting of tumor cells is indispensable, making it a better replacement for conventional chemotherapies by diminishing their adverse side effects. While designing a drug to be delivered selectively in the target organ, the drug development scientists should focus on various factors such as the type of cancer they are dealing with according to which drug, targeting moieties, and pharmaceutical carriers should be targeted. All published articles have been collected regarding cancer and drug-targeting approaches from well reputed databases including MEDLINE, Embase, Cochrane Library, CENTRAL and ClinicalTrials.gov, Science Direct, PubMed, Scopus, Wiley, and Springer. The articles published between January 2010 and December 2020 were considered. Due to the existence of various mechanisms, it is challenging to choose which one is appropriate for a specific case. Moreover, a combination of more than one approach is often utilized to achieve optimal drug effects. In this review, we have summarized and highlighted central mechanisms of how the targeted drug delivery system works in the specific diseased microenvironment, along with the strategies to make an approach more effective. We have also included some pictorial illustrations to have a precise idea about different types of drug targeting. The core contribution of this work includes providing a cancer drug development scientist with a broad preliminary idea to choose the appropriate approach among the various targeted drug delivery mechanisms. Also, the study will contribute to improving anticancer treatment approaches by providing a pathway for lesser side effects observed in conventional chemotherapeutic techniques.

In Vivo and In Silico Assessment of Diabetes Ameliorating Potentiality and Safety Profile of Gynura procumbens Leaves.

BACKGROUND: Diabetes mellitus is one of the most notable health dilemmas. Analyzing plants for new antidiabetic remedies has become an impressive territory for life science researchers. Gynura procumbens has long been used to treat diabetes. Thus, we strived to ascertain the hypoglycemic potentiality of extract of leaves of G. procumbens by in vivo and in silico approaches. METHODS: Fresh leaves of G. procumbens were collected and shade-dried to prepare ethanolic extracts to evaluate pharmacological parameters. Diabetes was induced in rats via injecting alloxan through the intraperitoneal route at a dose of 150 mg/kg body weight. Humalyzer 3000 was used to perform a biochemical assay of collected samples from rats. Anti-hyperglycemic activity study along with overdose toxicity test was performed. The pharmacological activity of this plant was also evaluated through a molecular docking study. This in silico study investigated the binding affinity of natural ligands from G. procumbens against glycoside hydrolase enzymes. RESULTS: We detected a peak plasma concentration of G. procumbens at 3 hours 45 minutes that is roughly similar to the peak plasma concentration of metformin. Again, in OGTT and anti-hyperglycemic tests, it has been ascertained that both plant extract and metformin can exert significant (P < 0.05) and highly significant (P < 0.01) hypoglycemic activity in a dose-dependent manner. Metformin exhibited better therapeutic efficacy than that of plant extract, but it possessed null statistical significance. Also, our safety profile expressed that, similar to metformin, the plant extract can restore the disturbed pathological state in a dose-oriented approach with a wide safety margin. In silico study also validated the potentialities of natural constituents of G. procumbens. Conclusion. This study suggested that G. procumbens can be considered as potential antidiabetic plant. Robust and meticulous investigation regarding plant chemistry and pharmacology in the future may bring about a new dimension that will aid in discovering antidiabetic drugs from this plant in the diabetes management system.

An evaluation of pharmacological healing potentialities of Terminalia Arjuna against several ailments on experimental rat models with an in-silico approach.

Herbal remedies have been used in many cultures for decades to treat illnesses. These medicinal plants have been found to contain various phytochemical compounds that can help to cure mild to severe illnesses. The inadequacies of conventional medicines and their unusual side effects sparked a determined search for alternative natural therapeutic agents. Another reason for this hunt could be the availability and fewer side effects of natural products. T. arjuna is widely used in traditional medicine to alleviate various diseases like relieving pain, ameliorating diabetes, mitigating inflammation, and back-pedaling of depression. In this study, the ethanolic extract of T. arjuna possesses a promising effect on the animal model (p < 0.05/p < 0.01) as an antihyperglycemic, analgesic, anti-inflammatory, and antidepressant agent, but in a dose-dependent manner. The lower dose of T. arjuna was found to be capable of reversing the disturbed physiological state at a significant level (p < 0.05). However, a higher dose of T. arjuna exerts better therapeutic effects for those diseases. This animal study aims to evaluate the anti-diabetic, anti-depressant, and anti-inflammatory properties of T. arjuna compared to conventional marketed drugs. We will perform an in-silico study for active constituents of T. arjuna against their proposed targets and look for the molecular cascade on their claimed pharmacological properties. This study shows that different doses of T. arjuna bark extracts give similar therapeutic responses compared with established marketed drugs in managing hyperglycemia, stress-induced depression, and inflammation. Besides, our docking study reveals that flavonoids and triterpenoid active constituents of T. arjuna play an important role in its usefulness. This study, therefore, scientifically confirmed the traditional use of this medicinal plant in the management of several diseased conditions.

A Retrospective Cross-Sectional Study Assessing Self-Reported Adverse Events following Immunization (AEFI) of the COVID-19 Vaccine in Bangladesh.

BACKGROUND: The Oxford-AstraZeneca vaccine (Covishield) was the first to be introduced in Bangladesh to fight the ongoing global COVID-19 pandemic. As this vaccine had shown some side-effects in its clinical trial, we aimed to conduct a study assessing short-term adverse events following immunization (AEFIs) in Bangladesh. METHOD: A cross-sectional study was conducted on social and electronic media platforms by delivering an online questionnaire among people who had taken at least one dose of the COVID-19 vaccine. The collected data were then analysed to evaluate various parameters related to the AEFIs of the respondents. RESULTS: A total of 626 responses were collected. Of these, 623 were selected based on complete answers and used for the analysis. Most of the respondents were between 30-60 years of age, and 40.4% were female. We found that a total of 8.5% of the total respondents had been infected with the SARS-CoV-2 virus. Our survey revealed that out of 623 volunteers, 317 reported various side-effects after taking the vaccine, which is about 50.88% of the total participants. The majority of participants (37.07%, 231/623) reported swelling and pain at the injection site and fever (25.84%, 162/623); these were some of the common localized and generalized symptoms after the COVID-19 vaccine administration. CONCLUSION: The side-effects reported after receiving the Oxford-AstraZeneca vaccine (Covishield) are similar to those reported in clinical trials, demonstrating that the vaccines have a safe therapeutic window. Moreover, further research is needed to determine the efficacy of existing vaccines in preventing SARS-CoV-2 infections or after-infection hospitalization.

A clinical evaluation of the alterations in the level of serum zinc, copper, iron, and manganese in the ischemic heart disease patients of Bangladesh - A case-control study.

BACKGROUND: Ischemic heart disease (IHD) is a major cause of death globally. Countries vary in their rates, and changes have occurred over time. Nowadays, developing countries pose new public health challenges. OBJECTIVES: The objective of the present study was to appraise the alterations in the levels of serum Zn, Cu, Fe, and Mn that occur in patients with ischemic heart disease and to depict the correlations of the effects of these changes that lead to the pathogenesis of IHD. METHODS: Zn, Cu, Fe, and Mn in the IHD patients were determined by Atomic Absorption Spectroscopy (AAS). RESULTS: This study evaluated 52 patients with IHD, and 61 healthy volunteers served as controls. The primary outcomes of interest were explored regarding the correlations of the serum levels of these trace elements in patients with IHD. The secondary outcomes were explored in terms of inter-element relations to connect them with the pathogenesis of IHD. Our study found significantly reduced levels of Zn and Cu (2.50 ± 0.19 mg/L and 2.52 ± 0.17 mg/L, respectively) and an elevated level of Fe (148.97 ± 17.25 mg/L) in the patient group with IHD. The level of Mn (7.32 ± 1.23 mg/L) was elevated in the sera of the patients with ischemic heart disease (IHD) compared to healthy control subjects. CONCLUSION: Our results indicate strong associations of the pathogenesis of IHD with depleted serum levels of Zn and Cu and elevated Fe and Mn levels, which may provide a prognostic tool for the treatment of this concerning the disease.

How the association between obesity and inflammation may lead to insulin resistance and cancer.

BACKGROUND AND OBJECTIVES: Obesity is associated with metabolic dysfunction and over nutrition. Increased body mass index and obesity are strongly amalgamated with changes in the physiological function of adipose tissue, leading to altered secretion of adipocytokines, inflammatory mediators release as well as chronic inflammation and insulin resistance. The purposes of this study were to review the evidence of how obesity and inflammation may lead to insulin resistance and cancer. SUMMARY: Recent findings suggested that increased level of inflammatory mediators in obesity, plays an introductory and cabalistic role in the development of different types of inflammatory disorders including type 2 diabetes mellitus. Link between elevated body mass index and type 2 diabetes mellitus (T2DM). Several of the factors-such as increased levels of leptin, plasminogen activator inhibitor-1, decreased levels of adiponectin, insulin resistance, chronic inflammation etc. consequently result in carcinogenesis and carcinogenic progression too. CONCLUSION: This review summarizes how cytokine production in adipose tissue of obese subject creates a chronic inflammatory environment that favors tumor cell motility and invasion to enhance the metastatic potential of tumor cells. High levels of cytokine in the circulation of affected individuals have been associated with a significantly worse outcome. This article also reconnoiters the mechanisms that link obesity to numerous disorders such as inflammation, diabetes, cancers and most specifically combine these processes in a single image. Understanding these mechanisms may assist to understand the consequences of obesity.

Genetic variants of SULT1A1 and XRCC1 genes and risk of lung cancer in Bangladeshi population.

Lung cancer is one of the most frequently occurring cancers throughout the world as well as in Bangladesh. This study aimed to correlate the prognostic and/or predictive value of functional polymorphisms in SULT1A1 (rs9282861) and XRCC1 (rs25487) genes and lung cancer risk in Bangladeshi population. A case-control study was conducted which comprises 202 lung cancer patients and 242 healthy volunteers taking into account the age, sex, and smoking status. After isolation of genomic DNA, genotyping was done by polymerase chain reaction-restriction fragment length polymorphism method and the lung cancer risk was evaluated as odds ratio that was adjusted for age, sex, and smoking status. A significant association was found between SULT1A1 rs9282861 and XRCC1 rs25487 polymorphisms and lung cancer risk. In case of rs9282861 polymorphism, Arg/His (adjusted odds ratio = 5.06, 95% confidence interval = 3.05-8.41, p < 0.05) and His/His (adjusted odds ratio = 3.88, 95% confidence interval = 2.20-6.82, p < 0.05) genotypes were strongly associated with increased risk of lung cancer in comparison to the Arg/Arg genotype. In case of rs25487 polymorphism, Arg/Gln heterozygote (adjusted odds ratio = 4.57, 95% confidence interval = 2.79-7.46, p < 0.05) and Gln/Gln mutant homozygote (adjusted odds ratio = 4.99, 95% confidence interval = 2.66-9.36, p < 0.05) were also found to be significantly associated with increased risk of lung cancer. This study demonstrates that the presence of His allele and Gln allele in case of SULT1A1 rs9282861 and XRCC1 rs25487, respectively, involve in lung cancer prognosis in Bangladeshi population.

Characterization of phytoconstituents and evaluation of antimicrobial activity of silver-extract nanoparticles synthesized from Momordica charantia fruit extract.

BACKGROUND: Our present study was conducted to characterize the phytoconstituents present in the aqueous extract of Momordica charantia and evaluate the antimicrobial efficacy of silver-extract nanoparticles (Ag-Extract-NPs). METHODS: Silver nanoparticles (AgNPs) were prepared by reducing AgNO3; and NaBH4 served as reducing agent. After screening of phytochemicals; AgNPs and aqueous extract were mixed thoroughly and then coated by polyaniline. These NPs were characterized by using Visual inspection, UV spectroscopy, FTIR, SEM and TEM techniques. Antimicrobial activities were assessed against Staphylococcus aureus, Salmonella typhi, Escherichia coli and Pseudomonas aeruginosa. RESULTS: Aqueous extract of M. charantia fruits contain alkaloid, phenol, saponin etc. UV-Vis spectrum showed strong absorption peak around 408 nm. The presence of -CH, -NH, -COOH etc. stretching in FTIR spectrum of Ag-Extract-NPs endorsed that AgNPs were successfully capped by bio-compounds. SEM and TEM result revealed that synthesized NPs had particle size 78.5-220 nm. Ag-Extract-NPs showed 34.6 ± 0.8 mm zone of inhibition against E. coli compared to 25.6 ± 0.5 mm for ciprofloxacin. Maximum zone of inhibition for Ag-Extract-NPs were 24.8 ± 0.7 mm, 26.4 ± 0.4 mm, 7.4 ± 0.4 mm for S. aureus, P. aeruginosa and S. typhi. We found that Ag-Extract-NPs have much better antibacterial efficacy than AgNPs and M. charantia extract has individually. It is also noticed that gram negative bacteria (except S. typhi) are more susceptible to Ag-Extract-NPs than gram positive bacteria. CONCLUSION: Ag-Extract-NPs showed strong antibacterial activity. In order to make a reliable stand for mankind, further study is needed to consider determining the actual biochemical pathway by which AgNPs-extracts exert their antimicrobial effect.

In vitro dissolution study of atorvastatin binary solid dispersion.

The aim of the present study was to improve the solubility and dissolution rate of atorvastatin (ATV), a slight water-soluble drug, by solid dispersion (SD) technique using a hydrophilic carrier Poloxamer 188 (POL188). Physical mixing (PM) and solvent evaporation (SE) method were used to prepare ATV-SD where different drug-carrier ratios were used. Prepared formulations were characterized in their solid state by solubility study; differential scanning calorimetry, scanning electron microscopy, and Fourier transform infrared spectroscopy which demonstrated changes in the formulations supporting the improved solubility. Percent content of POL188 in the SD matrix was found to play the pivotal role in the improvement of dissolution property of ATV. In case of PM, highest enhancement in drug release was found for 1:3 ratio (P < 0.05, ANOVA Single factor) whereas in case of SE, 3:0.5 ratio of ATV-POL188 resulted the maximum enhancement in ATV release (P < 0.05, ANOVA Single factor). Analysis of dissolution data of optimized formula indicated the best fitting with Peppas-Korsmeyer model and the drug release kinetics was fickian diffusion. In conclusion, binary SD prepared by both PM and SE technique using POL188 could be considered as a simple, efficient method to prepare ATV solid dispersions with significant improvement in the dissolution rate.

Theophylline loaded gastroretentive floating tablets based on hydrophilic polymers: preparation and in vitro evaluation.

This investigation describes the preparation and in vitro evaluation of gastroretentive floating tablet of theophylline. Two hydrophilic cellulose derivatives, Methocel K100M and Methocel K15MCR were evaluated for their gel forming and release controlling properties. Sodium bicarbonate and citric acid were incorporated as gas generating agents. The effects of soluble components (sodium bicarbonate and citric acid), gel forming agents and amount variation of theophylline on drug release profile and floating properties were investigated. Tablets were prepared by direct compression technique. Formulations were evaluated for in vitro buoyancy and drug release study was evaluated for eight hours using USP XXII paddle-type dissolution apparatus using 0.1N HCl as dissolution medium. The release mechanisms were explored and explained with zero order, first order, Higuchi and Korsmeyer equations. The release rate, extent and mechanisms were found to be governed by polymer and floating agent content. The content of active ingredient was also a vital factor in controlling drug release pattern. It was found that polymer content and amount of floating agent significantly affected the mean dissolution time, percentage drug release after 8 hours, release rate constant and diffusion exponent.