Lakhasly

ندي البادي, [٥‏/٥‏/٢٠٢٤ ٩:٥٣ م]
[ محوَّلة من ⁨ندي البادي⁩ ]
2.2. Apparatus: The liquid chromatographic system consists of Waters series equipped with a series PDA detector, series 515 quaternary pump, and manual injector rheodyne valve with fixed loop. The analytes were monitored at 220 nm. Chromatographic analysis was performed on column. 2.3. Chromatographic Conditions: The C 18 column equilibrated with mobile phase acetonitrile : methanol : phosphate buffer (50 : 20 : 30, v/v/v; pH 5.6) and adjusted with 0.01% O-phosphoric acid was used. The flow rate was maintained at 1 mL/min, eluents were monitored with UV detector at 220 nm, and the injection . Total run time was kept for 15 min.
2.4. Preparation of Standard Stock Solutions: separate 10 mL volumetric flasks and volumes were made up to the mark with mobile phase to yield a solution containing 1000 𝜇g/mL of CPM and IBU respectively. Appropriately diluted with mobile phase to obtain working standard of CPM 100 𝜇g/mL and IBU 1000 𝜇g/mL were used as a working standard.
2.5. Method Validation: The proposed method was subjected to validation for various parameters like linearity and range, precision, accuracy, and robustness in accordance with International Conference on Harmonization Guidelines.
2.5.1. Linearity: Appropriate aliquots of CPM and IBU working standard solutions were taken in different 10 mL volumetric flasks and diluted up to the mark with mobile
phase to obtain final concentrations of 0.5, 1.0, 1.5, 2.0, and 2.5 𝜇g/mL of CPM, 25, 50, 75, 100, and 125 𝜇g/mL of IBU, and 1.25, 2.50, 3.75, 5.00
respectively. The solutions were injected using a 20 𝜇L fixed loop system and chromatograms were recorded. Calibration curves were constructed by plotting average peak area versus concentrations and regression equations were computed for two drugs.
2.5.2. Precision: The repeatability studies were carried out by estimating response of CPM (2 𝜇g/mL) and IBU (100 𝜇g/mL) six times and results were reported in terms of relative standard deviation. The intraday and interday precision studies (intermediate precision) were carried out by estimating the corresponding responses 3 times on the same day and on 3 different days for three different concentrations of CPM (0.5, 1.5, and 2.5 𝜇g/mL), IBU (25, 75, and 125 𝜇g/mL), and the results were reported in terms of relative standard deviation.

Maha elsayed ♡, [٥‏/٥‏/٢٠٢٤ ٩:٥٣ م]
[ محوَّلة من ⁨Mai .⁩ ]
(.5.3.)The accuracy of the method was determined
by calculating recoveries of CPM, IBU, by method Chromatography Research International 
of standard additions. Known amounts of CPM (0, 0.5, 1.0,
and 1.5 𝜇g/mL), IBU (0, 25, 50, and 75 𝜇g/mL), were added to a prequantified
sample solution, and the amounts of CPM, IBU,
these values to the straight-line equation of calibration curve.
2.5.4. Detection  and Quantitation Limit. The LOD and LOQ were calculated using the following equation as per ICH
guidelines:
LOD = 3.3 × 𝜎/ 𝑆
LOQ = 10 × 𝜎/ 𝑆
where 𝜎 is the standard deviation of 𝑦-intercepts of regression
lines and 𝑆 is the slope of the calibration curve.
(2.5.5.)  Robustness of the method was studied by  changing the experimental conditions like flow
rate and percentage of mobile phase ratio. The study was
carried out by changing 5% of the mobile phase ratio and
0.1 mL/min of flow rate.
(2.5.6. )Solution Stability. The solutions were prepared and so-
lution stability was checked for 3, 9, 12, and 24 hrs  using the different analysts
and the same instrument.
(2.5.7. )System Suitability. Part of the method development to verify that the
system is adequate for the analysis of CPM, IBU,
(RT), tailing factor, asymmetry factor, and theoretical plates
for the five suitability injections were determined.
(2.6. )Analysis of Marketed Formulation. Twenty tablets were
accurately weighed and finely powdered. Tablet powder
equivalent to 4 mg CPM, 200 mg of IBU, and 10 mg
was taken in 100 mL volumetric flask. Methanol (50 mL) was
added to the above flask and the flask was sonicated for 15
minutes.The solution was filtered usingWhatman filter paper
No. 41 and volume was made up to the mark with the mobile
phase.
Appropriate volume of the aliquot was transferred to a
10 mL volumetric flask and the volume was made up to the
mark with the mobile phase to obtain a solution containing
1.0 𝜇g/mL of CPM, 50 𝜇g/mL of IBU, 
The solution was sonicated for 10 min. It was injected as per
the above chromatographic conditions and peak areas were
recorded. The quantifications were carried out by keeping
these values to the straight line equation of calibration curve.