The Rheological Behaviour Of Pharmaceutical Fluids Essays

The Rheological Behaviour Of Pharmaceutical Fluids Essays The Rheological Behaviour Of Pharmaceutical Fluids Essay The Rheological Behaviour Of Pharmaceutical Fluids Essay This study investigated the rheology of selected pharmaceutical fluids. The chief findings were that viscousness alterations with concentration, temperature and shear rate of the fluids tested. pharmaceutical fluids, rheology, viscousness, shear rate, pseudoplastic Most pharmaceutical fluids are macromolecular colloids that are can be used in suspensions and emulsions so proving conditions of high viscousness, easiness of pourability and hiking adhesion is important.1 This is achieved by measuring rheological footings and is related to the construction and molecular weight of the fluid. Viscosity is the opposition to motion of liquid and sheer rate is the speed gradient created from force of motion of flow. Three experiments were carried out, as described in the practical booklet1 without accommodations. Viscosity was measured with different concentrations, temperatures and sheer rates. Table 1:Viscosity at selected concentrations of Methylcellulose Concentration ( % ) 1 2 4 Viscosity ( cP ) 8.7 19.2 88. Table 2:Flow clip of 1 % PVP at two different temperatures Water Bath Temperature ( oC ) Mean Flow clip ( secs ) 25 291 40 195 Table 3:Viscosity of 0.8 % Tragacanth gum at selected sheer rates Rotation velocity ( revolutions per minute ) up incline 2 5 10 20 50 Sheer rate ( rpm/60 ) 0.033 0.083 0.167 0.333 0.833 Viscosity ( mPa.sec / cP ) 484.9 341.9 278.9 229.5 175.5 Rotation velocity ( revolutions per minute ) down incline 50 20 10 5 2 Sheer rate ( rpm/60 ) 0.833 0.333 0.167 0.083 0.033 Viscosity ( mPa.sec / cP ) 173.7 220.5 260.9 323.9 419.9 Graph 1:Rheogram: viscousness vs. sheer rate ( see attached ) Fromtable 1, viscousness additions exponentially with increasing concentration. Higher concentrations of methylcellulose ( linkages of A ; szlig ; D-glucose as precursor ) will incorporate more links and H bonds increasing stableness immensely, therefore exponential addition in viscousness. Fromtable 2, flow clip is decreased with increasing temperature. PVP is a polymer ( N-vinylpyrrolidone as precursor ) with C-C linkage between units. Increasing temperature breaks the bonds that hold the units together, take downing viscousness, bring forthing faster unstable rate, therefore less flow clip. Fromtable 3, viscousness is decreased with increasing shear rate with viscousness get downing to be given to a minimal value. Tragacanth is a polymer with high H adhering interaction with H2O and between the concatenation units ( web ) . Increasing shear rate, lowers interaction with H2O and detangles construction so molecules flow in right way, hence, take downing viscousness. Tragacanth exhi bits non-Newton behavior as viscousness is non changeless with increasing shear rate. Hysteresis cringle is seen as down incline is shifted the right of up incline demoing pseudoplastic thixotropic behavior. 2 Improvements to the experiment include increasing sum of repetitions, concentrations, temperature and sheer rates. Toconclude, seting concentrations, temperature and emphasis rate of fluids have an consequence on viscousness. This can hold many benefits for different utilizations of pharmaceutical industry. ( i.e. emulsifiers, binders, thickenings )