Development and evaluation of sustained release losartan potassium matrix tablet using kollidon SR as release retardant

O presente estudo foi realizado para desenvolver (SR) matriz de comprimidos de liberação sustentada de losartana, um antagonista da angiotensina II, para o tratamento da hipertensão arterial. Os comprimidos foram preparados pelo método de compressão direta com Kollidon SR como polímero de liberação lenta. A quantidade de losartana potássica permanece fixa (100 mg) para todas as três formulações enquanto que as quantidades de Kollidon SR foram de 250 mg, 225 mg e 200 mg para F-1, F-2 e F-3, respectivamente. A avaliação envolve três etapas- propriedades micromeríticas dos grânulos, estudo das propriedades físicas dos comprimidos e estudos de cinética de liberação in vitro.. Selecionoou-se o aparelho USP tipo II para realizar o teste de dissolução em meio com 900 mL de tampão fosfato pH 6,8 . O teste foi realizado em 75 rpm e a temperatura foi mantida a 37 ºC ± 0.5 ºC. Analisou-se a cinética de liberação utilizando-se vários modelos cinéticos. Conteúdo mais alto de polímero na matriz reduziu a taxa de liberação do fármaco. Em níveis mais baixos de polímero, a taxa e a extensão de liberação do fármaco foram aumentados. Todas as formulações seguiram a cinética de liberação de Higuchi, em que os valores do coeficiente de regressão (R2) foram 0,958 , 0,944 e 0,920 para F-1, F-2 e F-3, respectivamente, e elas apresentaram liberação do fármaco dominada pela difusão. Encontraram-se diferenças estatisticamente significativas (PThe present study was undertaken to develop sustained release (SR) matrix tablets of losartan potassium, an angiotensin-II antagonist for the treatment of hypertension. The tablets were prepared by direct compression method, along with Kollidon SR as release retardant polymer. The amount of losartan potassium remains fixed (100 mg) for all the three formulations whereas the amounts of Kollidon SR were 250 mg, 225 mg, and 200 mg for F-1, F-2, and F-3 respectively. The evaluation involves three stages: the micromeritic properties evaluation of granules, physical property studies of tablets, and in-vitro release kinetics studies. The USP apparatus type II was selected to perform the dissolution test, and the dissolution medium was 900 mL phosphate buffer pH 6.8. The test was carried out at 75 rpm, and the temperature was maintained at 37 ºC ± 0.5 ºC. The release kinetics was analyzed using several kinetics models. Higher polymeric content in the matrix decreased the release rate of drug. At lower polymeric level, the rate and extent of drug release were enhanced. All the formulations followed Higuchi release kinetics where the Regression co-efficient (R²) values are 0.958, 0.944, and 0.920 for F-1, F-2, and F-3 respectively, and they exhibited diffusion dominated drug release. Statistically significant (

Microscopic detection of chloroplast transgenic plastids using fluorescent probe

Background: Fluorescent marker genes have modernized many areas of molecular biology, specifically in plant biotechnology and genetic engineering studies. The use of fluorescent proteins permits the scientists to purify the desired clones visually in transformation work. Green fluorescent protein (gfp) derived from Aequorea victoria has been the most common and favorite fluorescent marker which is being widely used as a visual selection marker gene. It can be easily visualized under UV light without the involvement of any substrate and is non-destructive as well.Method: A species-specific chloroplast transformation vector was constructed with gfp as a fluorescent marker gene. The recombinant vector was biolistically integrated in tobacco plastome and transgenic cells were initially screened on spectinomycin containing regeneration medium.Results: The successful plastome integration was verified by using cellular DNA from drug resistant clones in PCR and southern blotting. The expression of gfp in transplastomic clones was microscopically investigated using simple florescent as well as confocal laser scanning microscopes.Conclusion: Regeneration of transgenic plants was significantly helped by visual identification of fluorescent at different stages of development, also enabling to identify the homozygous and heterozygous tissues. No toxic effect of the gfp was observed and lack of toxicity as maintained by normal phenotypic performance of plants.

Dynamics of Wheat Market Integration in Northern Punjab, Pakistan

The economy of Pakistan is largely dependent on the agriculture sector which contributes about 21 percent to the GDP and employs about 43.4 percent of the labour force. Agriculture and agro-based industrial products contribute about three fourth of the total foreign exchange earnings from export [Pakistan (2007)]. About 66 percent of the population lives in rural areas of Pakistan and directly or indirectly depends on agriculture for its livelihood. The welfare and participation of the rural population in the economy is therefore, central to the country’s progress. Despite the importance of agricultural sector in the national economy, there is a wide gap between food supply and demand due to low performance of agriculture [FAO (2000)]. The country is not producing enough commodities like wheat, rice and edible oil etc. to meet even the basic food needs of the population and as a consequence poverty is on the rise, particularly in the rural areas. In order to reduce poverty, agriculture has to grow faster and at a sustainable basis

Bleomycin induced pneumonitis: a case successfully managed with high-dose steroids

Bleomycin is a chemotherapeutic agent used in a number of solid organ malignancies.1-3 It accumulates in the skin and lungs resulting in skin ulceration and associated pulmonary toxicity. Its use is somewhat limited due to its significant pulmonary adverse effects with bleomycin induced pnemonitis (BIP) as the commonest and most dreaded complications. The overall incidence of pulmonary toxicity is as high as 10% and it is fatal in 1-2%.3,4 We present a case of BIP which was successfully managed by the aggressive use of high dose steroids with complete resolution

Phenotypes of Alpha 1 Antitrypsin in Karachi, Pakistan

Objective: To determine serum level of the protease inhibitor, to identify phenotypes and determine their frequencies. Study Design: A prospective study. Setting: PMRC Research Centre, JPMC and the Aga Khan University Hospital Karachi. Subjects: Healthy aduIts without history ol peptic ulcer disease and a normal endoscopy. Methodology: Quantitive measurement of serum alpha 1 AT was carried out by radial immunodiffusion. phenotyping by iso-electric focusing and confirmation of phenotypes by immunofixation and DNA analysis technique. Results:Serum alpha I AT was low in 13.4% of the subjects. Ni MM phenotype predominated followed by SZ SS, MZ and ZZ. DNA diagnosis accurately resolved the phenotypes as S and Z. Conclusion: Frequency by phenotype associated with total and intermediate deficiency is less in the populatio

Macroeconomic Shocks: Short-Run versus Long-Run Perspectives

Shocks that stem from goods and money markets are supposed to be influential as it takes some time for economic agents to realize their true impacts. Therefore, these shocks can induce uncertainty about key macroeconomic variables such as CPI inflation and real GDP growth. Impacts of nominal and real shocks are computed, evaluated and compared under short-run as well as under long-run restrictions for CPI inflation and real GDP. Furthermore, different countries with varying resource structures are incorporated to achieve a comprehensive and generalized analysis. Structural VAR models are employed in order to functionalize short-run and long-run restrictions. Impulse response analysis is done to analyze effects of nominal and real shocks on CPI inflation and real GDP in short-run as well as in long-run. Variance decompositions are done to locate main sources of uncertainties in CPI inflation and real GDP. Shocks from product market appeared to be more pervasive in comparison to shocks from money market

Macroeconomic Shocks: Short-Run versus Long-Run Perspectives

Shocks that stem from goods and money markets are supposed to be influential as it takes some time for economic agents to realize their true impacts. Therefore, these shocks can induce uncertainty about key macroeconomic variables such as CPI inflation and real GDP growth. Impacts of nominal and real shocks are computed, evaluated and compared under short-run as well as under long-run restrictions for CPI inflation and real GDP. Furthermore, different countries with varying resource structures are incorporated to achieve a comprehensive and generalized analysis. Structural VAR models are employed in order to functionalize short-run and long-run restrictions. Impulse response analysis is done to analyze effects of nominal and real shocks on CPI inflation and real GDP in short-run as well as in long-run. Variance decompositions are done to locate main sources of uncertainties in CPI inflation and real GDP. Shocks from product market appeared to be more pervasive in comparison to shocks from money market

Genetic Variants of Serum Alpha 1 Antitrypsin

Complete absence of data on alpha 1 antitrypsin in this country prompted us to determine serum levels using radial immunodiffusion (RID) and phenotypes by isoelectric focusing (IEF) in 100 healthy adults (52 males and 48 females). Mean serum alpha 1 antitrypsin concentration in healthy subjects was 2.47±0.08 g/l and the main phenotypes MM (70%), M1 M2 (28%) and FM 3(2%) are infrequent in our population (JPMA 45:245,1995)