Analysis of Coldeze Super pharmaceutical cold and flu remedy solution. Introduction Medications intended to treat the common cold often contain a number of active ingredients which may be separated by various means and analysed. Modern separation techniques may yield a tranche of both quantitative and qualitative data regarding the composition of a sample. An umbrella term for modern separation techniques is chromatography, which covers a wide range of separatory methods, some of the more widely used including thin layer chromatography (TLC); gas chromatography (GC), and reverse phase high performance liquid chromatography (RP - HPLC). Each approach varies in terms of speed, expense, performance parameters, and so on; from the more basic information provided by TLC (key data : the Rf = distance spot travels / distance solvent travels) to the multitude of quantitative/qualitative/performance parameters which it is possible to determine via RP-HPLC, for example. In this procedure, the composition of an oral solution for cold and flu - Coldeze Super, was investigated and an attempt was made to analyse the exact proportions of its active ingredients. The stated proportions of the active substances were 250 mg/5ml paracetamol, 20 mg/ml caffeine and 10 v/v % ethanol. Methods and materials Thin Layer Chromatography for chemical analysis of analgesics solution Three TLC plates were spotted with standard solutions for caffeine, paracetamol, aspirin and ibuprofen, and Coldeze Super, an oral pharmaceutical solution of unknown content. Each plate was developed with a different mobile phase and R f values recorded. Solvents used: 1. 95: 5 % ethyl acetate : acetic acid; 2. 100 % ethyl acetate, 3. 50 % ethyl acetate : 50 % hexane
Analysis of Cold and Flu Remedy Solution
Sep 17, 2015
Medications intended to treat the common cold often contain a number of active ingredients which may be separated by various means and analysed.
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Analysis of Coldeze Super pharmaceutical cold and flu remedy solution.Introduction
Medications intended to treat the common cold often contain a number of active ingredients which may be separated by various means and analysed. Modern separation techniques may yield a tranche of both quantitative and qualitative data regarding the composition of a sample.An umbrella term for modern separation techniques is chromatography, which covers a wide range of separatory methods, some of the more widely used including thin layer chromatography (TLC); gas chromatography (GC), and reverse phase high performance liquid chromatography (RP - HPLC). Each approach varies in terms of speed, expense, performance parameters, and so on; from the more basic information provided by TLC (key data : the Rf = distance spot travels / distance solvent travels) to the multitude of quantitative/qualitative/performance parameters which it is possible to determine via RP-HPLC, for example.In this procedure, the composition of an oral solution for cold and flu - Coldeze Super, was investigated and an attempt was made to analyse the exact proportions of its active ingredients. The stated proportions of the active substances were 250 mg/5ml paracetamol, 20 mg/ml caffeine and 10 v/v % ethanol. Methods and materialsThin Layer Chromatography for chemical analysis of analgesics solutionThree TLC plates were spotted with standard solutions for caffeine, paracetamol, aspirin and ibuprofen, and Coldeze Super, an oral pharmaceutical solution of unknown content. Each plate was developed with a different mobile phase and Rf values recorded. Solvents used:
1. 95: 5 % ethyl acetate : acetic acid;
2. 100 % ethyl acetate, 3. 50 % ethyl acetate : 50 % hexaneThe process initially gave no useful result and so was repeated with a freshly acquired set of TLC plates, which did then yield useful data. Analysis of ethanol by GLCIn order to determine the ethanol content of the unknown Coldeze Super solution, an analytical GLC apparatus containing a packed column at a fixed temperature with a nitrogen flow rate of approx. 50 cm3.min-1 and flame ion detector was utilized, with the method of internal standards for calibration. (Waters Alliance 2695 System 28, Column: Zebron Waxplus, Column Length 15 metres, Carrier gas hydrogen 5.5psi Flow Rate - ~3ml/min, Injection Temp 100C Injection Temp 230 C Detector 1: 150).Solutions, as shown in Table 1, were made up in 25cm3 volumetric flasks to the proportions shown, topped up with distilled water, and mixed thoroughly. From each flask, approximately 1l was injected into the apparatus.Table 1. GLC calibration standard preparation
No.Ethanol /cm3Gives % (v/v) EthanolPropan-1-ol / cm3Gives % (v/v) Propanol
10.2511.506
20.5021.506
30.7531.506
41.0041.506
51.2551.506
61.5061.506
71.7571.506
82.0081.506
92.2591.506
102.50101.506
A malfunction with the GLC apparatus arose approximately halfway through the laboratory session, which prevented any further data from being collected. As an exercise in gaining familiarisation with the techniques involved, data from a previous session were used in order to plot absolute peak area and peak area ratios for ethanol and propan-1-ol. (Table 2)
Table 2: Data from a previous session
Tables 3 & 4. Determination of mean and SDEtOH area 1 (V.s)23489.34Peak area ratio0.65
EtOH area 2 (V.s)27901Peak area ratio 20.676279
EtOH area 3 (V.s)27270.53Peak area ratio 30.653025
EtOH area mean26220.29Peak area ratio mean0.66
EtOH area SD2385.988Peak area ratio SD0.013727
Analysis of paracetamol and caffeine by HPLCInstrumental ConditionsMobile phase: 50:50 v/v MeOH:H2OInjection loop: 20 microlitres
Column: 25 cm, 4mm i.d .containing 5 m silica coated with octadecylsilane (5micrometres C18)Detector: 273nm, ~0.1 AUFS
Flow rate: ~1 cm3 min-1Premarked solutions of paracetamol and caffeine were provided of varying concentrations as shown in Table 5 below. Each was injected in turn and chromatographs were obtained for all.Table 5. Concentrations of paracetamol and caffeine
SolutionParacetamol concentration (mg.dm-3) Paracetamol area (V.s)Caffeine concentration (mg.dm-3) Caffeine area (V.s)
A5009622455.15002762202.4
B0122868.69100526923.5
C1001693137.0900
D50690865.494001740623.09
E4003937017.1503606631.71
F3002183863.112001185123.68
G2001544197.363001295327.94
A rough calibration plot was plotted from the data. Due to time constraints it was not possible to run a duplicate calibration chromatogram.
Next, 2.5cm3 of the unknown oral solution was diluted to 50 cm3 with methanol, labelled, then from this, 5 cm3 was taken and diluted to 50cm-3 with methanol. This was injected and a chromatogram was obtained.Results and discussionThin layer chromatographyAs a simple, inexpensive method for basic chemical separation, thin layer chromatography was an ideal first line procedure.
A first set of chromatograms failed to develop at all, indicating a problem with the TLC plate such as prior adsorbtion of water. From the second set, similarities in Rf values were found in two out of the three TLC solvent systems used, strongly indicating the presence of paracetamol and caffeine in the unknown sample. In the acid containing system, no solution movement at all was detected, which could again indicate a problem with the TLC plate.The most efficient system in terms of solute separation distance was found to be the 50 : 50 hexane : ethyl acetate which was in line with expectations since the compounds in question contain both polar and non-polar moieties. Identical Rf values were recorded for the unknown and the standard paracetamol sample, and fairly close values for the caffeine. A mixture of other proportions of solvent in order to achieve a further variance/ spread of polarities may separate with further accuracy.Table 6. TLC dataMobile phaseSolvent front Paracetamol front (cm)Paracetamol
Rf valueCaffeine front (cm)Caffeine Rf valueIbuprofen front (cm)Ibuprofen Rf valueUnknown front 1Unknown f. 1 valueUnknown front 2U2 Rf value
95:55----------
10052.81.790.855.884.41.140.95.62.71.85
50:5050.77.140.316.63.81.320.25200.77.14
Analysis of ethanol by GLCSince the volumes of liquid used in GC at the microlitre scale, errors are often introduced during calibration. In order to mitigate this, an indirect method of standardisation is used; the method of internal standards. However, with this method, great care must be taken to ensure accuracy. The data used in this investigation were of dubious accuracy. EtOH in unknown = 23489.34; 29275.53, 23489.34
Mean area EtOH in unknown = 24751.40
SD = 2185.95
Calculation of unknown: y = mx + cy = 4267.6x 5593.2
(y+5593.2) / 4267.6 = x
x = 7.11The concentration of EtOH in the unknown was found to be 7.11 % v/v
Analysis of paracetamol and caffeine by HPLC
Errors appear to have been introduced during the procedure of calibration. This was noted during the laboratory session but time constraints restricted the availability of the HPLC apparatus. In future the researchers will need to plan more proactively rather than relying on scheduled as/when availability of equipment.Fig 1 Sample chromatograph
References
Higson. Seamus. Analytical Chemistry EMBED Excel.Chart.8 \s
EMBED Excel.Chart.8 \s
_1495241120.xlsChart1
2987.7
11126.4
6862
7948
11069
13279
15965
16665
51156.65
41728.99
EtOH Concentration (% v/v)
Area EtOH (V.s)
GC Calibration: EtOH area vs. concentration
Sheet1
No.EtOH absolute peak area (V.s)EtOH %v/vProp. peak area
12987.7136153.64
211126.4242484.32
36862341398.06
47948471977.38
511069515515
613279615310
715965716464
816665814923
951156.65940924.42
1041728.991032082.42
%EtOO v/vEtOH peak area ratio
10.0826389819
20.2618942706
30.1657565596
40.1104235803
50.7134386078
60.8673416068
70.969691448
81.1167325605
91.2500274897
101.3006808713
Sheet1
EtOH Concentration (% v/v)
Peak area ratio
GC calibration: peak area ratios against EtOH conc.
EtOH Concentration (% v/v)
Area EtOH (V.s)
GC Calibration: EtOH area against concentration
_1495241088.xlsChart1
690865
1693137.09
1544197.36
2183863.11
3937017.1
9622455.1
Para Area
Concentration (mg.dm3)
Area (V.s)
HPLC calibration: Paracetamol
Sheet1
SolutionPara concPara areaCaff concCaff. Area
A5009622455.15002762202.4ParacetamolCaff conc.Caff areaPara ConcPara Area
B0122868.69100526923.5
C1001693137.0900d0.0050.00690865.00
D50690865.494001740623.09c100.001693137.09
E4003937017.1503606631.71g200.001544197.36
F3002183863.112001185123.68f300.002183863.11
G2001544197.363001295327.94e400.003937017.10
a500.009622455.10
Sheet1
Para Area
Concentration (mg.dm3)
Area (V.s)
HPLC calibration: Paracetamol
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