Digital analytical balance

A drying oven (Digital Heat, J.P. Selecta, Spain) was used to dry-washed wheat grain samples. A stainless steel mixing machine (Moulindex, France) was used to grind and powder the dried wheat sample. A digital analytical balance (Mettler Toledo, Switzerland) with ±0⋅000 g precision was used to measure the wheat samples. 100 ml round bottom flask with reflux condensers were used in the Kjeldahl heater (Gallenkamp, England) to digest samples of dried wheat flour and powdered wheat flour. Measuring bottles (Duran, Germany), beakers, volumetric vials and pipettes were used to measure different volumes of sample solution, acid reagents and metal standard solutions. Buck Scientific Model 210VGP AAS, East Norway, USA flame atomic absorption spectrometer equipped with deuterium arc background correctors and hollow cathode lamps with air-acetylene flame was used for the determination of Mn, Fe, Ni, Cu, Zn, Pb and Cd in wheat flour sample.

Using a Digital Analytical Balance (Mettler Toledo, Greifensee, Switzerland) with a sensitivity of 0.10 mg, all {TP (1) + water (2)} combinations were created on a mass basis. The mass fraction of TP used to make various {TP (1) + water (2)} compositions ranged from 0.10–0.90. Three replicates of each {TP (1) + water (2)} composition were made.
Using a standard shake-flask method [32 ], the mole fraction solubility of CNZ against the mass fraction of TP (w₁ = 0.0–1.0; w₁ is TP mass fraction in {TP (1) + water (2)} compositions) and pure solvents was tested from 293.2–313.2 K and at 0.1 MPa in various {TP (1) + water (2)} mixtures and pure solvents. Extra CNZ crystals were mixed with known amounts of each {TP (1) + water (2)} composition and neat solvents. Three repetitions of each experiment were carried out. Inside the Biological Shaker (Julabo, PA, USA), the acquired samples were saturated for three days to achieve equilibrium. After reaching equilibrium, the saturated samples were withdrawn from the shaker and centrifuged at 5000 rpm. The supernatants were withdrawn, diluted (wherever applicable), and used for the estimation of CNZ content using a reported HPLC method at 253 nm [12 (link)]. The mole fraction solubilities (x_e) of CNZ were calculated using their standard formulae [20 (link),33 (link)].

All (IPA + H₂O) solvent mixtures were prepared on mass, using a “Digital Analytical Balance (Mettler Toledo, Greifensee, Switzerland)” with a sensitivity ± 0.10 mg. The mass fraction of IPA for different (IPA + H₂O) solvent mixtures was varied by 0.10 from 0.10–0.90. Each solvent mixture was obtained in triplicates.

The weights of prepared ODMTs (n = 20) were obtained using a digital analytical balance (Mettler-Toledo, Columbus, OH, USA). The ODMTs were weighed individually, and the average weight was calculated and compared to the acceptance value mentioned in the United States Pharmacopeia (USP). Content uniformity (CU) of the prepared ODMTs was determined according to the following procedure. Ten tablets were individually crushed, dissolved in methanol, and filtered through a 0.45 µm membrane filter. Sildenafil content was analyzed using an HPLC (HPLC, Waters 1525, Milford, MA, USA) system equipped with UV detection at 292 nm. The sample analysis was carried out according to the method described by Yi et al. with modification [18 (link)]. If all 10 tablets attained drug content within 85–115% of the target potency and Relative Standard Deviation (RSD) was less than 5.0%, the prepared ODMTs were considered uniform [6 (link)].