The present study was proposed to formulate an oral delivery device, in the form of a bi-layer tablet in which first layer is formulated to obtain a prompt release of one drug i.e. hydrochlorothiazide, with the aim of reaching a high serum concentration in a short period of time. The second layer is a prolonged-release hydrophilic matrix containing another drug i.e. captopril, which is designed to maintain an effective plasma level for a prolonged period of time. The immediate release layer and sustained release layer was optimized separately and then constituted in bilayer tablet. Different viscosity grades of HPMC (i.e. HPMC K4M, K15M, and K100M), Xanthan gum and combination of HPMC and Xanthan gum were used as matrix forming material for sustaining release of captopril. Sustained release layer was optimized by swelling studies and dissolution studies of prepared matrices. Drug release from tablets containing Xanthan gum was slightly faster as compared to HPMC formulations. In case of HPMC matrix tablet the drug release depends on concentration and viscosity grade of polymer used. Immediate release layer was formulated using different concentration of disintegrants like Croscarmellose sodium and Crospovidone. Disintegration time and drug release were taken as the basis to optimize the immediate release layer. Crospovidone in the concentration of 4 % gives fasted disintegration in 13 sec. Bilayer tablet was prepared from optimized formulation of immediate and sustained release layer. Prepared bilayer tablet formulations were subjected to stability studies for thirty days which showed stability with regards to release pattern.
Keywords: Bilayer tablet; Matrix tablet; HPMC; Xanthan gum; Direct compression.
INTRODUCTION
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...d hydrochlorothiazide combination therapy may include improved compliance and synergistic reductions in blood pressure with an accomplished reduction in side effects10.
On the basis of these considerations, in the present study it was proposed to formulate an oral delivery device, in the form of a bi-layer tablet in which first layer was formulated to obtain a prompt release of hydrochlorothiazide, with the aim of reaching a high serum concentration in a short period of time. The second layer was a prolonged-release hydrophilic matrix containing captopril, which was designed to maintain an effective plasma level for a prolonged period of time. The combination of a fast release pulse with a slow release pattern could allow for an easier and more flexible optimization of the fast and slow dose fractions as a function of the pharmacokinetics and metabolism of the drug.
“The key factor in limiting royal power in the years 1399-1509 was the king’s relationship with parliament.”
Ace Inhibitors are used to treat hypertension and congestive heart failure (CHF). Most of the drugs that are Ace Inhibitors have the common ending –pril. It inhibits an enzyme; that decreases the tension of blood vessels and the blood volume, thus lowering blood pressure. Lotensin (benzapril) comes in tablets and is used for oral administration. It is one of the ace inhibitors that are indicated for treating hypertension. There is warning while using Lotensin when pregnant, it indicates to stop using immediately when pregnancy is detected. Vasotec (enalpril) comes in tablets and injection. It is indicated for the treatment of hypertension and is effective alone or in combination with other Ace Inhibitors agents, especially thiazide-type diuretics. There is a warning for fetal toxicity; when pregnancy is detected; stop using.
Between 1450 and 1750, political, economic, and artistic changes affected Western Europe. Politically, in the 1400's parts of Europe had a feudalistic government and feudal monarchies but overtime Europe adapted to absolute monarchies, parliamentary monarchies, and nation-states. Economically, with feudalism declining, capitalism and mercantilism grew with the commercial revolution. In the arts, there was a change from the mostly religious art of the middle Ages to the Renaissance focus on realism, and humanistic ideas during the enlightenment revolution, also new scientific ideas during the scientific revolution.
During the period 1500 to 1815 studied in class there were numerous developments in Europe. In many ways it was a fast growing period. There were numerous reforms that affected the educational, political, and economical system of countries. Furthermore, scientific developments have also occurred which lead to advances in exploration and military. I believe that the most important development was the printing press, which connected Europe, so that ideas can be communicated. Furthermore, the “Age of Exploration,” was a significant development that leads to an increased knowledge of the seas, which eventually helped the welfare of coastal countries. Another development that was important was the scientific revolution, more specifically how their
1066: The Year of the Conquest, written by David Howarth, tells of one of the most important dates in the history of England. In 1066, William the Conqueror and William of Orange fought the historical Battle of Hastings. The outcome of this battle lead to many changes to the English people. The Norman people became assimilated into the English way of life. Howarth proceeds to tell the tale of the Battle of Hastings through the eyes on a common Englishman.
With the decline of the Western Roman empire Western Europe was a disjointed land that had no true unifying structure till the rise of Christianity. In Roman antiquity people used the State or empire of Rome to define themselves and give them a sense of unity despite having a diverse group of people within the empire. When Western Rome fell this belief based on a Roman cultural identity disappeared and no longer were people able to identify themselves with any particular group as they once have. The Christian religion was able to fill this vacuum by having the people associate themselves to a religion instead of a given state or cultural group. During Medieval Europe Christianity became the unifying force that would define what it meant to be European. Christianity gave political leaders legitimacy by showing that they have been favored by the gods. The clergyman that recorded the histories surrounding the kings of the Medieval Europe also provided a link to the Roman Empire to give the Kings a link to Roman empire of antiquity. Christianity became the center of the cultural life in western Europe and created a new social elite in Europe which would dominate literacy and knowledge within Europe for centuries. Christianity provided Europe with an escape from the disorder of the Medieval ages and give them a spiritual outlet for their fears and desires for a better life, whether in the physical life or in the spiritual world after death.
WAS THE TIME PERIOD BETWEEN 400 AD AND 1400 AD A “DARK AGE” FOR EUROPE?
Norman Davies, a leading English historian, wrote, “There is an air of immobility about many descriptions of the medieval world” (Davies 291). However, these descriptions he refers to do not capture the true essence of the Middle Ages of Europe, which were a continuation and a formation. They were a continuation of old Rome in race, language, institutions, law, literature, arts, and in cultures independent of Rome. Nevertheless, the Middle Ages were not merely a continuation; they were the formation of our world. Many modern-day historians argue that the so-called Dark Ages were a period of ascent rather than of descent, that with the withering of the pagan classic civilization came the first budding of a new culture that was to develop into our modern civilization. James M. Powell, a prominent historian, agreed with this argument concerning the untold progress of this age. Powell believed that the Medieval Ages was a multi-faceted period of time in which the roots of modern civilization began to emerge, and that it was. This time period was critical because, although it seemed to be a dark age, seeds were being planted for future generations such as ours. These seeds have sprouted and have given us templates to work with regarding issues of centralization, the economy, scholasticism, education, expressions of art, and religion.
Size and stability: Liquid formulation can be bulky, difficult to transport and store.1 During storage under the stated conditions, it’s necessary that oral solutions are not subject to precipitation, fast sedimentation, caking or formation of lump.2 They have poor stability compare to solid dosage form formulation due to hydrolysis.1 Therefore, it’s important to optimize the active ingredient stability in liquid formulation including those prepared from powder or granules.2
As we discussed above that pharmacokinetic and pharmacodynamics can be seen as two sides of the same coin in order to gain better understanding of their efficacy and safety profiles.” Generally it is possible to make fairly robust predictions of the pharmacokinetic profile in man using in vitro systems and preclinical pharmacokinetic studies. A previously published survey on the causes of failure in drug development indicated that inappropriate pharmacokinetics were a major cause such as; factors as low bioavailability due to high extraction or poor absorption characteristics, short elimination half-life leading to short duration of action and excessive variability due to genetic or environmental factors. This observation has led to an increased emphasis on pharmacokinetic input to the drug discovery process throughout the pharmaceutical industry. However, it is important to realise that this may only permit the rejection of compounds to b...
Leonard G.S., Tovey G.D., Lee R.M., (1979) The Pharmaceutical Development and Bioavailability of Cimetidine Capsule and Tablet Formulations, DRUG DEVELOPMENT AND INDUSTRIAL PHARMACY, 5 ( 2 ) , pp 217-226.
Throughout time, history has taken some strange turns. A single ruler establishing some new form of government can transform entire civilizations, or a single event can lead to the creation of a great new people. Whatever the case, history can repeat itself in time. One possible exemption of this could be Britain’s time period of the Middle Ages. Bearing a distinct and unique culture relative to the time period, some of the values and the customs held during this time have yet to be repeated in history. It is perhaps the most unique period of all time for the British Isles.
Inject able medications are usually supplied in vials or ampoules, each requiring different techniques for withdrawal of the medication. Before entering a vial, it is necessary to spray or swab the rubber closure on the top of the vial with 70% isopropyl alcohol. An alcohol swab should be used only once and on only one
The Middle Ages encompass one of the most turbulent periods in English History. Starting with the Battle of Hastings and the Norman Conquest - when William the Conqueror effectively took all of the lands from the Saxon English and gave them to French nobles. The English Middle Ages then saw the building of the great English castles, including the Tower of London, which helped the Normans to retain their hold on England. The start of the Crusades and the knights of the Middle Ages, including the founding of the Knights Templar. The Domesday Book and the Magna Carta. The Kings and Queens of the Middle Ages including Richard the Lionheart and great Plantagenet Kings from Henry II (1154-1189) to Edward III (1327-1377). The Hundred Years War between England and France. The Medieval Kings and Queens of the Royal Houses of Lancaster and York and the Wars of the Roses. The Middle Ages Feudal System and the terrible Black Death which really did plague the period of the Middle Ages.The Middle Ages 1066-1485