Theoritically, as the concentration of sodium alginate increases, the diffusion ability of the substrate into the beads will be decreased. This is because to more cross-linking at higher concentrations with more calcium binding sites. That is the reason why beads at high concentration appear bright white in color. At lowest concentration of sodium alginate, immobilization effectiveness will be higher. However, the gel at lowest concentration cannot withstand wear tear and very fragile.
Upon finding the actual concentrations of salicylic acid, concentration of aspirin in the flask at various times can be found using the equation [aspirin]t = [aspirin]0 – [salicylic acid], since at constant volume, number of moles of initial aspirin decrease to form salicylic acid. Initial concentration of aspirin formed as follows: [aspirin]0 = 0.212g / (180.157gmol-1 * 50/1000 L) = 0.0235 mol L-1. Thus using the first test as sample, [aspirin]t = 0.0235 – 9.981*10-4 = 0.0225 mol L-1. To find the rate constant, we will need to log the value of [aspirin]t and plot it against time to find the rate constant. Figure 1 shows the diluted and actual concentrations of salicylic acid, the concentration and log value of aspirin at various times.
Regression coefficient and slope values are calculated and interpreted. The regression coefficient value of this plot was found to be 0.984 and the slope was found to be 0.699 (figure 17). Figure 17: Koresmeyer plot for Optimized formula Hixson Crowell Model: In this model, graph is plotted between Cubic root of % drug remaining Vs time. Regression coefficient and slope values are calculated and interpreted. The regression coefficient value of this plot was found to be 0.985 and the slope was found to be 0.112 (figure 18).
C=1- ρο/ρα ………………………………………………. (Equation 6) The Kawakita plots of P/C against P were established. The slope of the plot represents the a value, which reflects the total volume reduction for the powder bed (compressibility) constant b reflects the plasticity of the powder. Elastic Recovery N. A. Armstrong and R. F. Haines-Nutt, Elastic recovery and surface area changes in compacted powder systems, J. Pharm. Pharmacol.
SYSTEM SUITABILITY THEORETICAL PLATES: A standard solution of 25 µg mL-1of Amoxicillin trihydrate (in triplicate) was prepared and same was injected, then the system suitability parameters were calculated. Theoretical plates per meter Theoretical plates per meter were calculated from the data obtained from the peak using the following expression n = (5.54Vr2)/LWh2 Theoretical plates per column Theoretical plates column were calculated from the data obtained from the peak. n = (5.54Vr2)/Wh2 Where, ‘n’ is number of theoretical plates per meter, ‘Vr’ is the distance along the base line between the point of injection and a perpendicular dropped from the maximum of the peak of interest and ‘Wh’ is the width of the peak of interest at half peak
Analysis was carried in three replicates with the spiking standard ascorbic acid (99.9% purity) concentration of 0.02 mg/ml at the levels of 50%, 100%, and 150%. The % recovery was calculated. Range: The data generated in precision and linearity was considered for establishment of Range. The sample weight of 1250 mg to 3750 mg was taken for analysis and it was found to be within the linearity and precise. Robustness: Reliability of the method was done about deliberate variations in method parameters like a.
On the other hand, the pharmacokinetic character attribute to triptolide’s toxicology. The pharmacokinetic studies showed that triptolide owns good systemic uptake and high plasma protein binding affinity, which is partly due to its high lipophilicity. The transporter P-gp and BCRP play a very important role in the absorption and accumulation of triptolide in tissues, inhibition or inducton the transporter will cause potential drug-drug interaction, which would lead to inefficacy and toxicity of triptolide. The triptolide molecules are subsequently excreted predominantly biotransformed after absorption. Moreover, the metabolism of triptolide can occur either in hepatocytes or extrahepatocutes, leading to the low drug exposure of the parent drug.
As the stearyl group is at 1-postion in GMS, lipase favors its hydrolysis . Pancreatic lipase possesses higher affinity towards MCT compared to LCT. Hence, NLCs containing MCT will be hydrolyzed more extensively during in vitro lipolysis [83, 85]. The study conducted by Dahan and Hoffman showed that the hydrolysis of MCT of the lipid based formulation has resulted in a high concentration of lipophilic drug solubilized in the aqueous phase when compared to LCT and short chain triglyceride (SCT). Also, the formulations containing MCT underwent a complete lipolysis; hence, no undigested oil remained after the digestion of 30 min
This formulation is equipotent to Diprivan but is associated with a higher incidence of pain on injection.24 An alternative to emulsion formulations of propofol and associated side effects (pain on injection, risk of infection, hypertriglyceridemia, pulmonary embolism) is creation of a prodrug (Aqauvan) by cleaving groups to the parent compound that increase its water solubility (phosphate monoesters, hemisuccinates). Propofol is liberated after hydrolysis by endothelial cell surface alkaline phosphatases. In this regard, injection of the water-soluble prodrug results in propofol and dose dependent sedative effects. Compared with propofol, this prodrug has a larger volume of distribution and higher potency.24 A nonlipid formulation of propofol uses cyclodextrins as a solublilizing agent. Cyclodextrins are ring sugar molecules that form guest (propofol)-host complexes migrating between the hydrophilic center of the cyclodextrin molecule and the water-soluble phase.
In particular, the formulation of rosuvastatin, molecule which is generally lipophilic, poses real problems owing mainly to their low solubility in aqueous liquid pharmaceutical excipients, to their propensity to precipitate or recrystallize in aqueous solution and to their low solubility in the fluids of the gastrointestinal tract from which they must be absorbed. The bioavailability of an active ingredient also depends on its concentration in the gastrointestinal fluid, said concentration itself being dependent on the release of the active ingredient. In particular, the more lipophilic an active ingredient is, the less tendency it has to migrate in gastrointestinal fluids. The above said problem can be overcome by nanoparticle drug delivery