Plants as potential source of antimicrobial agents

For microbial infections, either caused by bacteria or fungi, antibiotics are employed. After the discovery of antibiotics it was thought that infectious diseases will no longer exist. But due to irrational use of antibiotics, a number of bacterial strains with multi-drug resistance have emerged (khan et al., 2009) and due to infectious diseases millions of people die every year (Dubey et al., 2012). It is a bitter fact that infectious diseases are the leading cause of the premature deaths which result in approximately fifty thousand deaths annually around the globe (Ahmad and Beg, 2001). The unnoticeable use of antimicrobials both in developing and developed countries led to the creation of microbial resistance problems. It also makes the treatment difficult especially in immunocompromised patients (Ahmad and Beg, 2001).Plants and plant products have been used as medicines since the start of history. Many researchers have conducted research on the plant products to check their antimicrobial effects (Abu-shanab et al., 2004). The oldest known method for healing is the use of plant. Using higher plants for treatment of diseases had started since the man started to live on this planet (Onyeagba et al., 2004). Traditional medicines including the herbal medicines are used at least for primary health care in some domains in almost every country. In the developing countries about 70-95% patients depends on the natural medicines. In 2008 the worldwide market of natural medicine was of 83 billion US$ and on annual basis there is exponential increase in this bill. Legal concerns about the herbal/natural medicines vary widely from state to state and country to country and these medicines are used as self-medicines, health foods, functional foods, homes care remedies, over the counter medicines, prescription medicines etc. The quality of the herbal/traditional medicines is very difficult to control and maintain consistently. WHO in cooperation with its local and regional offices has made Good Agricultural and Collection Practices (GACP) and Good Manufacturing Practices (GMP) in addition to technical support and assistance for standardization for creation of high quality products. For understanding the approaches of quality, safety and efficacy which are based on research are needed to evaluate the traditional or herbal medicines (Robinson and Zhang, 2011). Search for the relief from infection from natural resources (plants etc.) is not a new idea. People from all over the world use the plant products for healing e.g. it is evident that Neanderthals who lived 60,000 years ago in the present day Iraq used hollyhock, and these plants are still widely used in the ethanomedicine all around globe. Hippocrates mentioned 300-400 medicinal plants in the late 5th century B.C (Cowan, 1999). A number of plants contain compounds that have antibacterial property (Khan et al., 2011). Compounds such as emetine, berberine and qunine which are derived from plants are very effective for the infectious microbes (Iwu et al., 1999). On the earth there are more than 3, 00,000 plant species and only about 2% of plants have been checked so for, for their antimicrobial properties. Plants extracts from more than 157 plant families have been described which have potential antimicrobial properties (Narayan et al., 2010). In United States of America (USA) about 1/4th to 1/2th of the pharmaceuticals dispensed have their origin of higher plants (Cowan, 1999). Medicine which in near past had been derived from natural resources include taxol, camptothecin (anticancerous) and artemisinin (antimlarial). These and many other drugs clearly show that plants serve the potential source of medicine even today

Pharmacokinetic Interactions of Rosuvastatin: A Review

Rosuvastatin was claimed a “super-statin” to lower the LDL cholesterol comparing with other statins. An excellent benefit-risk profile of Rosuvastatin makes it more acceptable to treat dyslipidemia.   Safety profile is also comparable with other marketed statin. This statin is widely prescribed to treat hyperlipidemics in combination with other drugs. Interactions with other co-prescribed drugs might potentiate or lower its therapeutic effectiveness. This review accentuates the origin of rosuvastatin in the family of statins and highlights the various interactions specifically pharmacokinetic interactions with other drugs that are commonly prescribed in its combination. Keywords: Rosuvastatin, Interactions, Statins, Hyperlipidemi

Clopidogrel Interactions: Consider while prescribing

Clopidogrel reduces the cardiovascular risks because of inhibitory action on platelets aggregation but some co-administered drugs compromise its main therapeutic effects. Clopidogrel is a prodrug and converted into active metabolite by the hepatic cytochrome P450. The active thiol metabolite inhibits the P2Y12 adenosine di-phosphate receptors and decrease the platelet aggregation processes. The activity of clopidogrel is dependent on the metabolic conversion by cytochrome P450 due to this fact proton pump inhibitors, atorvastatin and several other drugs that competitively inhibit the clopidogrel metabolism might alter its therapeutic response. Conversely other agents potentiate the clopidogrel responsiveness by inducing the cytochrome activity. Combinational drug therapy increases the risks of drug-drug interactions. The previous pharmacodynamic studies have reported clinically significant risks that are associated with combined therapy of clopidogrel with other drugs which are commonly used in coronary artery disorders. These reported studies did not demonstrate the consistent evidence for sever drug-drug interaction hazards in cardiovascular events. This review highlights the various controversies among the studies about common clopidogrel interactions when prescribed in various cardiovascular disorders to achieve targeted therapeutic outcomes. The clopidogrel is commonly prescribed in many serious disorders such as cardiovascular, hypercholesteraemia and lack of information or uncertainty may cost serious outcomes. Keywords: Clopidogrel, Interactions, Cardiovascular, Proton pump inhibitor

Optimization and validation of high performance liquid chromatography-ultra violet method for quantitation of metoprolol in rabbit plasma: application to pharmacokinetic studies

Purpose: To develop a sensitive, simple and validated high performance liquid chromatography (HPLC) analytical method for the determination of metoprolol tartrate in rabbit plasma.Methods: Mobile phase of methanol and 50 mM ammonium dihydrogen phosphate solution (50:50) at pH 3.05 was used for separation of metoprolol on BDS hypersil C18 column at a wavelength of 223 nm. Flow rate and retention time were 0.6 mL/min and 7.4 min, respectively. For pharmacokinetic study, rabbits were given an oral dose of 8 mg/kg of metoprolol in solution form. Blood samples were taken from jugular vein of the rabbits after drug administration and analysed by HPLC.Results: Separation of metoprolol was not interfered with other components in plasma. The calibration curve was linear in the range of 25 - 1000 ng/mL (r2 = 0.997). Lower limits of detection (LLOD) and quantitation (LLOQ) were 8.87 and 25 ng/mL, respectively. Relative standard deviation (RSD) of intraday and inter-day precision was < 14.27 and 7.61 %, respectively. Relative error of accuracy was between 4.85 and 14.37 %. Maximum plasma concentration (Cmax), time to maximum plasma concentration (Tmax) and half-life (t½) after metoprolol oral administration in rabbits were 186.29 ng/mL, 0.50 h and 2.27 h, respectively.Conclusion: A simple, accurate and precise HPLC-UV method for metoprolol determination in rabbit plasma has been successfully developed and applied to a pharmacokinetic study.Keywords: HPLC-UV, Metoprolol, Pharmacokinetics, Rabbit plasma, Liquid-liquid extraction, Validatio

Evaluation and comparison: antipyretic activity in compound products of herbal pharmaceutical industries

To reduce an elevated body temperature various antipyretics drugs and medicinal plants are used. This study was designed to evaluate the antipyretic claim compound herbal syrups manufactured by three different herbal pharmaceutical companies of Pakistan. Bukharin (Hamdard Laboratories), Fever-X (Qarshi Industries) and Bukharok (Ashraf Laboratories) products were tested in rabbits. The experimental conditions were produced by E. coli suspension in animal model whereas 150 mg/Kg Paracetamol suspension was used as positive control. Doses with concentration of 5 ml/Kg of syrup were administered to check temperature lowering effect. The administration of Bukharin, Fever-X and Bukhrok significantly reduced the rectal temperature of animals. It was concluded that Bukharok and Bukharin syrups are good antipyretic drug products as they lowered 3 and 2.5 ?C temperature respectively. Keywords: Antipyretic effect, Herbal Syrups, Comparison with Allopathic Medicin

Investigating Shades of Modality in an Autobiography, “If I am Assassinated”: A Corpus-Based Analysis

This study investigated the attitudes and shades marked by the writer in an autobiography through the corpus expressions developed on modalities (i.e., boulmaic, deontic, epistemic, and perceptual). The study also put to the test the patterns created to examine modality across fiction genre. A corpus was created for this purpose and tagged using the Parts of Speech (POS) Tagger for analysis using AntConc 3.4.4.0. This analysis was then further interpreted using Simpson\u27s (1993) model. It was discovered that the author used many modalities, such as (un)certainty, attitude, point of view, ability, possibility, and likelihood, to form the meaning in the autobiography. These features highlighted the text\u27s persuasiveness, interest, and realism. By including these features, the autobiography was given positive and negative undertones that helped readers comprehend the author\u27s perspective. In conclusion, the content seemed more upbeat than downbeat. The deontic and boulomaic modalities that indicated estrangement and uncertainty on the writer\u27s part were used to mark the positive shade. Additionally, the use of the suggested patterns was successful in analysing the modality aspects using corpus techniques. They were suggested in the study as a paradigm for additional research. &nbsp

Fabrication and Evaluation of Rosuvastatin Calcium Fast- Disintegrating Tablets Using β-Cyclodextrin and Superdisintegrants

Purpose: To formulate fast-disintegrating tablets (FDT) of rosuvastatin calcium (RST) using β- cyclodextrin (CD) and different superdisintegrants to enhance their solubility.Methods: A total of 15 FDT formulations of RST were prepared using three different techniques. The FDTs were evaluated for micromeritic properties, as well as by Fourier transform infrared spectroscopy (FTIR), thermal analysis, disintegration time (DT), dissolution rate, powder x-ray diffraction (XRDP), scanning electron microscopy (SEM) and stability studies.Results: XRDP showed that RST was changed from crystalline to amorphous form. SEM images revealed the presence of small microscopic pores that enhanced water penetration and provided rapid dissolution rate compared with the pure drug. There was maximum release of drug (99 %) from F4 formulation containing solid dispersion of RST, CD and superdisintegrants. DT and wetting time were 25 s (p = 0.032) and 33 s (p = 0.023), respectively, for F4 formulation. In vitro dispersion time was also lowest for F4 at 23 s (p = 0.023). FTIR and DSC studies also confirmed complex formation of drug with CD and superdisintegrants.Conclusion: FDT is a suitable strategy to enhance the dissolution rate of RST and thus is an effective tool to improve bioavailability of poorly water soluble drugs.Keywords: Solubility, β-cyclodextrin, Kyron, Polymer, Rosuvastatin, Fast-disintegrating tablet

Comparative Translational Semiotic Analysis of ‘The River of Fire’ through Systemic Functional Linguistic Approach

This study aimed to: find out semiotic devices in literary texts in the light of Halliday’s transitivity process; and classify De Saussure’s two-part model of sign and thereby know that what logical connections lie between transitivity processes and semiotic devices. Data comprised of the text of a novel ‘The River of Fire’ by Qurratulain Hyder and analyzed through qualitative and quantitative methods. UAM software was used for the analysis of SFL transitivity processes and De Saussure’s model of sign was employed to analyze the language as a system of the sign. This process was applied to both versions (i.e. English and Urdu) of the same novel to compare the results. In this way, comparative technique was also utilized. As a result, all process types were observed in English and Urdu texts. Material and relational were the most characteristic processes in English and Urdu texts respectively. Through the analyses of English and Urdu texts of the novel, the processes of transitivity were observed involving the semiotic model of the sign. In addition, the signifier and signified were observed through the processes of systemic functional linguistics which meant that there existed a logical connection between semiotic devices and transitivity process

Formulation design and characterization of a non-ionic surfactant based vesicular system for the sustained delivery of a new chondroprotective agent

A diacereína é usada para o alívio sintomático e para a regeneração da cartilagem na osteoartrite. Devido aos efeitos adversos gastrointestinais, baixa solubilidade aquosa e biodisponibilidade, o seu uso clínico tem sido restrito. O objetivo do presente estudo foi melhorar o perfil de dissolução deste fármaco e obter liberação prolongada através do planejamento de um novo sistema de liberação designado de niossoma. Cinco formulações distintas de niossomas (F1 a F5) contendo tensoativos não iônicos (monoestearato de sorbitano) e colesterol, em diferentes proporções, de 5:5, 6:4, 7:3, 8:2 e 9:1, foram desenvolvidas através da técnica de evaporacão de fase reversa. Os tamanhos e índices de polidispersibilidade (PDI) obtidos variam entre 0,608 e 1,01 µm e entre 0,409 e 0,7781, respectivamente. Imagens de microscopia electrônica de varrimento (SEM) da formulação selecionada (F3) revelaram vesículas esféricas. Obteve-se encapsulação de 79,8% com a formulação F3 (7:3). Estudos de dissolução usando o método de diálise demonstraram padrão de liberacão prolongada para todas as formulações. A proporção de tensoativo e colesterol (7:3) na formulacão F3 prolongou o tempo de liberação do fármaco (T50%) até 10 horas. Estudos de modelação cinética demonstraram ordem de liberacão zero (R2=0,9834) e o expoente de liberação "n" do modelo de Korsmayer-Peppas (n=0.90) confirmou a liberação não-fickiana e anômala. Os resultados deste estudo sugerem que a diacereína pode ser encapsulada com sucesso no interior de niossomas, utilizando monostearato de sorbitano, o qual tem potencial para liberar, eficientemente, a diacereína no local de absorção.Diacerein is used for symptomatic relief and cartilage regeneration in osteoarthritis. Due to gastrointestinal side effects, poor aqueous solubility and low bioavailability, its clinical usage has been restricted. The objective of the present study was to enhance its dissolution profile and to attain sustained release by designing a novel delivery system based on niosomes. Five niosomal formulations (F1-F5) with non-ionic surfactant (sorbitan monostearate) and cholesterol in varying ratios of 5:5, 6:4, 7:3, 8:2 and 9:1 were developed by the reverse-phase evaporation technique. The size and polydispersivity index (PDI) were found in the range of 0.608 µm to 1.010 µm and 0.409 to 0.781, respectively. Scanning electron microscopy (SEM) of the selected formulation (F3) revealed spherical vesicles, and 79.8% entrapment was achieved with F3 (7:3). Dissolution studies using the dialysis method showed sustained release behaviour for all formulations. The optimized surfactant-to-cholesterol concentration (7:3) in formulation F3sustained the drug-release time (T50%) up to 10 hours. Kinetic modelling exhibited a zero-order release (R2=0.9834) and the release exponent 'n' of the Korsmayer-Peppas model (n=0.90) confirmed non-fickian and anomalous release. The results of this study suggest that diacerein can be successfully entrapped into niosomes using sorbitan monostearate and that these niosomes have the potential to deliver diacerein efficiently at the absorption site

Formulation and in vitro evaluation of mucoadhesive controlled release matrix tablets of flurbiprofen using response surface methodology

The objective of the current study was to formulate mucoadhesive controlled release matrix tablets of flurbiprofen and to optimize its drug release profile and bioadhesion using response surface methodology. Tablets were prepared via a direct compression technique and evaluated for in vitro dissolution parameters and bioadhesive strength. A central composite design for two factors at five levels each was employed for the study. Carbopol 934 and sodium carboxymethylcellulose were taken as independent variables. Fourier transform infrared (FTIR) spectroscopy studies were performed to observe the stability of the drug during direct compression and to check for a drug-polymer interaction. Various kinetic models were applied to evaluate drug release from the polymers. Contour and response surface plots were also drawn to portray the relationship between the independent and response variables. Mucoadhesive tablets of flurbiprofen exhibited non-Fickian drug release kinetics extending towards zero-order, with some formulations (F3, F8, and F9) reaching super case II transport, as the value of the release rate exponent (n) varied between 0.584 and 1.104. Polynomial mathematical models, generated for various response variables, were found to be statistically significant (PO objetivo do presente estudo foi formular comprimidos mucoadesivos de flurbiprofeno, de liberação controlada, e otimizar o perfil da liberação do fármaco e a bioadesão, utilizando a metodologia de superfície de resposta. Prepararam-se os comprimidos via técnica de compressão direta, que foram avaliados in vitro quanto aos parâmetros de dissolução e da força bioadesiva. Planejamento com componente central para dois fatores em cinco níveis cada foi empregado para esse estudo. Carbopol 934 e carboximetilcelulose sódica foram tomados como variáveis independentes. Efetuaram-se estudos de espectroscopia por transformada de Fourier (FTIR) para observar a estabilidade do fármaco durante a compressão direta e para avaliar a interação a fármaco-polímero. Aplicaram-se vários métodos cinéticos para avaliar a liberação do fármaco dos polímeros. Gráficos de superfície de contorno e de resposta foram efetuados para retratar a relação entre as variáveis dependentes e a resposta. Os comprimidos mucoadesivos de flurbiprofeno apresentaram cinética de liberação não-fickiana, estendendo para ordem zero, para algumas formulações (F3, F8 e F9), alcançando transporte super caso II, à medida que o valor do expoente (n) de taxa de liberação variou entre 0,584 e 1,104. Modelos matemáticos polinomiais, gerados por diversas variáveis de resposta, foram estatisticamente, significativos (