Instrumental methods of identification
Author: Ponnusamy Rajeswaran, Paul L. Kirk
Pages: 19 to 33
Creation Date: 1962/01/01
Note by the editor: This is the concluding part of the article, of which parts I and II were included in volume XIII, Nos. 3 and 4, respectively, of the
Bulletin on Narcotics.
|
X-ray Diffraction Powder Analysis
In recent years, X-ray diffraction data have come into prominence for the characterization of drugs by revealing data on crystal structure and molecular composition. The crystalline structure in different polymorphic forms may be studied, and permanent records of the photographed powder patterns may be used for comparison purposes.
The method has been successfully utilized for the study and identification of alkaloids, barbiturates, analgesics, sedatives, and anticonvulsants (1-5). A few of the tranquillizing compounds reported in this work have also been investigated previously (6).
A total of forty-six compounds were examined, most of them obtained in their pure commercial forms. A few of them were extracted from the common dosage forms. For convenience, the three innermost strong lines out of ten are indicated for comparison and indexing purposes.
Experimental
Powdered samples were sprinkled on a glass slide which had been lightly smeared with Corning stop-cock grease. They were subjected to copper-K alpha radiation in a Norelco (North American Phillips Co.) Geiger counter X-ray spectrometer, type No. 42322, after mounting on a rotating specimen holder. The instrument was equipped with a recording potentiometer (Brown Electronik strip chart, paper speed 18 inches per hour), and the characteristic diffraction patterns obtained over a 45°arc in duplicate.
The instrument was calibrated over this range, using powdered quartz crystals, and mean readings were used to compute the "d" values. The position of the slide was changed in obtaining the duplicate recordings, and variations of 0-20 minutes resulted.
Results
The "d" values for the six groups of drugs investigated are shown in table 4. The values for the alkaloid reserpine from three different sources are reported and will be found to tally closely.
TABLE 4
The "d" distances using Cu K-alpha radiation
Promazine
|
Promethazine
|
Ethopropazine
|
Trimeprazine
|
Pyrathiazine
|
11.1 | 7.91 | 9.40 | 7.72 | 10.5 |
8.54 |
7.18
[
a]
|
7.57
[
a]
|
7.18 |
7.70
[
a]
|
5.56 | 6.71 |
5.69
[
a]
|
6.42
[
a]
|
7.24 |
5.28
[
a]
|
5.60 | 4.69 |
6.14
[
a]
|
6.88 |
5.06 |
5.23
[
a]
|
4.22 |
4.92
[
a]
|
5.00
[
a]
|
4.19
[
a]
|
4.95
[
a]
|
4.08 | 4.76 | 4.70 |
3.89 | 4.45 | 3.90 | 4.26 | 4.48 |
3.69
[
a]
|
3.90 | 3.78 | 3.85 |
4.36
[
a]
|
3.39 | 3.70 |
3.53
[
a]
|
3.72 | 3.68 |
3.17 | 3.30 | 3.26 | 3.33 | 3.26 |
Chlorpromazine
|
Proclor-perazine
|
Proclor-perazine ethane disulfonate
|
Proclor-perazine dimaleate
|
Perphenazine
|
10.6 | 8.49 | 10.3 | 6.17 | 7.30 |
7.86 | 7.36 |
6.87
[
a]
|
5.43 |
6.15
[
a]
|
5.69
[
a]
|
5.62
[
a]
|
5.73
[
a]
|
5.05 | 5.53 |
4.77
[
a]
|
5.46 | 5.13 |
4.69
[
a]
|
4.87 |
4.42 | 4.55 | 4.86 | 4.43 | 4.54 |
4.29 | 4.37 |
4.60
[
a]
|
4.11
[
a]
|
3.86 |
3.93
[
a]
|
4.22
[
a]
|
4.30 |
3.51
[
a]
|
3.74 |
3.63 | 3.92 | 3.84 | 3.07 | 3.67 |
3.49 |
3.63
[
a]
|
3.54 | 2.62 |
3.48
[
a]
|
3.23 | 3.38 | 3.39 |
2.83
[
a]
|
|
1.66 | ||||
Triflu-promazine
|
Trifluo-perazine
|
Fluphenazine
|
Methoxy-promazine
|
Mepazine
|
14.5 | 7.79 | 18.2 | 8.83 | 7.64 |
7.98 |
5.84
[
a]
|
9.07
[
a]
|
6.94
[
a]
|
6.17
[
a]
|
7.23 | 5.10 |
8.71
[
a]
|
5.39 | 5.64 |
5.28
[
a]
|
4.55 | 6.07 | 5.09 |
4.78
[
a]
|
4.80
[
a]
|
4.35
[
a]
|
5.63 |
4.74
[
a]
|
4.24 |
4.54
[
a]
|
4.06
[
a]
|
4.85 | 4.50 | 4.02 |
4.44 | 3.79 |
4.54
[
a]
|
4.39 | 3.78 |
4.08 | 3.59 | 4.32 |
3.76
[
a]
|
3.68 |
3.84 | 3.46 | 4.02 | 3.63 | 3.59 |
3.60 | 3.24 | 3.75 | 3.20 |
3.09
[
a]
|
Reserpine Serpasil (Ciba)
|
Reserpine (Panray)
|
Reserpine (Lilly)
|
Deserpidine
|
Rescinnamine
|
13.16 | 13.0 | 13.0 | 13.0 | 6.06 |
12.3 | 12.3 | 12.2 |
12.1
[
a]
|
4.68
[
a]
|
7.51
[
a]
|
7.46
[
a]
|
7.48
[
a]
|
7.42
[
a]
|
3.84
[
a]
|
5.79 | 7.26 | 5.77 | 6.92 |
3.42
[
a]
|
5.39 | 5.76 |
5.04
[
a]
|
5.39 | 3.33 |
5.07
[
a]
|
5.05
[
a]
|
4.80
[
a]
|
5.02 | 2.90 |
4.81
[
a]
|
4.80
[
a]
|
4.50 |
4.75
[
a]
|
2.49 |
4.53 | 4.50 | 4.26 | 4.49 | 2.29 |
4.28 | 4.26 | 3.73 | 4.24 | |
3.74 | 3.74 | 3.45 | 3.59 |
Adiphenine
|
Diphenyl-pyraline
|
Captodiamine
|
Chlorcyclizine
|
Benactyzine
|
8.29 | 9.46 | 6.34 | 7.66 |
8.23
[
a]
|
7.22 |
8.49
[
a]
|
5.91 | 5.99 |
6.96
[
a]
|
6.03 | 7.88 | 5.06 |
4.97
[
a]
|
5.99 |
5.25
[
a]
|
6.03 | 4.89 | 4.40 | 5.44 |
4.51
[
a]
|
4.74
[
a]
|
4.71 |
4.21
[
a]
|
4.86 |
4.44 |
4.47
[
a]
|
4.39
[
a]
|
4.07 |
4.52
[
a]
|
4.10
[
a]
|
4.08
[
a]
|
3.81 |
3.85
[
a]
|
4.22 |
3.96 | 3.70 |
3.74
[
a]
|
3.66 | 3.79 |
3.79 | 3.16 | 3.67a | 3.24 | 3.59 |
3.39 | 3.44 | 3.11 |
Strong.
Pipradol
|
Azacyclonol
|
Hydroxyzine
|
Meclizine
|
Buclizine
|
11.0 | 7.51 |
14.2
[
a]
|
13.9 | 13.4 |
8.41
[
a]
|
7.03
[
a]
|
6.58 |
12.l
[
a]
|
7.57
[
a]
|
7.34
[
a]
|
5.30 | 6.03 |
7.50
[
a]
|
6.75 |
6.27 |
4.44
[
a]
|
5.85
[
a]
|
6.37 | 6.26 |
4.65 | 4.32 | 5.12 | 6.06 |
4.77
[
a]
|
4.50
[
a]
|
4.08 | 4.24 | 5.56 | 4.47 |
3.64 |
3.79
[
a]
|
4.01 | 5.17 | 4.24 |
3.52 | 3.67 | 3.73 | 4.69 | 4.03 |
3.29 | 3.29 | 3.53 | 4.14 |
3.79
[
a]
|
3.05 | 2.83 |
3.27
[
a]
|
3.84 | 3.11 |
Phenaglycodol
|
Mephenesin
|
Meprobamate
|
9.37 | 15.6 | 14.0 |
8.20 | 7.81 | 8.10 |
6.42
[
a]
|
6.54
[
a]
|
6.87
[
a]
|
5.99 |
5.85
[
a]
|
4.72
[
a]
|
5.73
[
a]
|
5.46
[
a]
|
3.95
[
a]
|
4.96 | 5.19 | 3.69 |
4.79 | 4.82 | 3.51 |
4.50 | 4.20 | 3.13 |
4.14
[
a]
|
4.13 | 2.74 |
3.05 | 3.90 | 2.36 |
Phenelzine
|
β-phenyl-isopropyl-hydrazine
|
Isocarboxazide
|
Iproniazid
|
Nialamide
|
18.9 | 10.8 | 9.73 | 9.04 | 15.3 |
9.85
[
a]
|
7.55 | 5.97 |
7.98
[
a]
|
9.63 |
6.51 | 5.99 | 4.92 | 5.79 |
7.68
[
a]
|
5.42
[
a]
|
5.38
[
a]
|
4.84 | 4.64 |
5.16
[
a]
|
4.89
[
a]
|
5.05
[
a]
|
4.67 |
4.49
[
a]
|
4.79
[
a]
|
3.90
[
a]
|
4.49
[
a]
|
4.30
[
a]
|
4.31
[
a]
|
4.44 |
3.24 | 4.29 |
4.08
[
a]
|
4.19
[
a]
|
4.18 |
2.79 | 3.60 |
3.73
[
a]
|
3.87 |
3.54
[
a]
|
2.44 | 3.53 | 3.55 | 3.37 | 3.18 |
3.41
[
a]
|
3.43 | 2.96 | 3.00 | |
Acetyl-
|
Ectylurea
|
Oxonamide
|
carbromal
|
Glutethimide
|
6.45 | 10.2 | 6.42 | 10.3 | |
4.72
[
a]
|
9.23
[
a]
|
5.62 | 7.24 | |
4.00 |
7.98
[
a]
|
4.87 | ||
3.76
[
a]
|
5.04
[
a]
|
4.69 | 6.04 | |
3.18
[
a]
|
4.60 |
4.41
[
a]
|
5.13
[
a]
|
|
2.78 | 4.42 |
4.25
[
a]
|
4.56 | |
2.75 | 4.03 | 3.62 |
3.79
[
a]
|
|
3.48 | 3.36 | 3.60 | ||
3.38 | 3.18 | 3.26 | ||
3.14 | 3.21 |
Methyl-phenidate
|
Thonzyl-amine
|
Pyrro-butamine
|
Chlor-methazanone
|
Imipramine
|
Betazole
|
10.8 | 8.52 | 16.6 | 7.95 | 10.4 | 4.95 |
8.62
[
a]
|
5.86
[
a]
|
7.12 |
6.61
[
a]
|
8.74 |
3.76
[
a]
|
7.03 | 5.45 | 5.74 |
5.48
[
a]
|
7.36
[
a]
|
3.57 |
6.18 |
4.69
[
a]
|
4.53 | 4.81 | 6.98 |
3.32
[
a]
|
5.86
[
a]
|
4.52 |
4.24
[
a]
|
4.53 | 5.59 | 3.11 |
4.56 |
4.30
[
a]
|
4.16
[
a]
|
4.27
[
a]
|
4.97
[
a]
|
2.92
[
a]
|
4.28
[
a]
|
4.22 |
3.98
[
a]
|
4.08 |
4.26
[
a]
|
2.84 |
3.87 | 3.97 | 3.86 | 3.90 |
4.16
[
a]
|
2.77 |
3.77 | 3.60 | 3.60 | 3.40 | 3.78 | 2.65 |
3.56 | 3.14 | 3.32 | 3.28 | 2.65 | 2.14 |
2.64 |
Ultraviolet Absorption Spectrophotometric Identification
Spectrophotometric procedures are invaluable for the identification and assay of compounds of toxicological interest. Selective absorption in some portion of the spectrum, depending only on chemical structure, is useful for nearly all compounds.
The ultraviolet absorption is useful for most, but not all, compounds of interest, but will not distinguish between many closely related compounds.
Ultraviolet absorption data have been reported by several workers in the narcotics field: Bradford & Brackett (6); Ebstein & Van Meter (7); Farmilo (8); Goldbaum (9, 10); Grant & Jones (11); Ketelaar & Helingman (12); Ostreicher, Farmilo & Levi (13); Rotandaro (14); Smith & MacDougal (15); Hill, Castano & Lightburn (16); Williams (17). Table 5 of this paper includes the useful absorption data for 32 of the tranquillizer and related drugs; curves for 42 are shown in plates 7 to 15. Measurements were made on the available commercial forms in most cases. In a few instances, extraction from prescription forms was employed.
Experimental Procedure
Stock solutions of each of the drugs in 50% alcohol were diluted to prepare a test solution of 10 ppm. In one of those reported (Nialamide-Nardil) the test solution was 50 ppm.
For the Rauwolfia group of alkaloids, stock solutions of three preparations of reserpine, Rauwolfia whole root powder, deserpidine, rescinnamine, and the alseroxylon fraction were prepared in 95% alcohol. These were diluted to give test solutions of 10 ppm. The concentration of the phenothiazine derivative thioridazine was not determined, as all available extracted material was used (less than 100 mg).
Manual plots in the ultraviolet range 200 mμ to 400 mμ were made with a Beckman model DU spectrophotometer. The same quartz cells of 1 cm light path were used for the preparation of all curves. A blank solution of 50% alcohol in the same cell was used throughout in all tests. Absorption was measured at intervals ranging from 10 mμ, 5 mμ, and 1 mμ at points of inflection.
All the plots were made on special paper [ 2] (log log 1/T log λ) as reported in the study of Bradford & Brackett (6). This type of plotting gives curves which are reasonably independent of concentration. The curves obtained for the phenothiazine class of derivatives were compared with those obtained on a Cary Automatic Recording Spectrophotometer, model 14.
The quartz 1 cm path cells were calibrated using the same solvent, and corrections ranging from 0.025 at 210 mμ to 0.005 at 250 mμ and 0.001 at 300 mμ were applied at the maximum and minimum absorbance points. Inasmuch as the absorbances were all measured under a single standardized set of conditions, it is apparent that deviations of pH, solvent, and other factors will have an influence on the values listed. Such differences must not be neglected when other conditions are utilized.
Results
Absorbance = log I
o
|
I
|
I o - Intensity of light transmitted by solution blank.
I - Intensity of light transmitted by test solution plus blank.
Absorptivity = D
1c |
D - Absorbance.
1- light path of cell 1 cm.
c- concentration in ppm.
The specific absorbance E = Absorptivity at a concentration of 1 ppm for a light path of 1 cm.
Values reported in table 5 are: λmax.
|
E max.
|
λmin.
|
E min.
|
Spectral absorbance data are presented in table 5 for the following compounds:
Group
A
|
Group B (Continued)
|
Promazine hydrochloride
|
Reserpine (Panray)
|
Promethazine hydrochloride
|
Deserpidine
|
Ethopropazine hydrochloride
|
Group C
|
Trimeprazine tartrate
|
Chlorcyclizine hydrochloride
|
Pyrathiazine hydrochloride
|
Hydroxyzine hydrochloride
|
Chlorpromazine hydrochloride
|
Meclizine hydrochloride
|
Proclorperazine dihydrochloride
|
Group D
|
Proclorperazine ethane disulfonate
|
Phenaglycodol
|
Proclorperazine dimaleate
|
Mephenesin
|
Perphenazine
|
Group E
|
Thiopropazate dihydrochloride
|
Phenelzine dihydrogen sulphate
|
Triflupromazine hydrochloride
|
Iproniazid phosphate
|
Trifluoperazine dihydrochloride
|
Nialamide
|
Fluphenazine dihydrochloride
|
Acetylcarbromal
|
Methoxypromazine maleate
|
Group F
|
Mepazine hydrochloride
|
Thonzylamine hydrochloride
|
Thioridazine hydrochloride
|
Pyrrobutamine phosphate
|
Group B
|
Chlormethazanone
|
Reserpine (Lilly)
|
Imipramine hydrochloride
|
Reserpine (Ciba)
|
Spectral absorbance curves are reproduced, in plates 7 to 15, for all of the above compounds and the following additional ones, under the same experimental conditions:
Group B
|
Group C (continued)
|
Reserpine whole root powder
|
Azacyclonol hydrochloride
|
(Squibb)
|
Buclizine hydrochloride
|
Group C
|
Group E
|
Adiphenine
|
β-Phenyl isopropyl hydrazine
|
Diphenylpyraline
|
Isocarboxazide
|
Banactyzine hydrochloride
|
Ectylurea
|
Pipradol hydrochloride
|
Glutethimide
|
A number of other compounds, examined in a similar manner, are not reported because experimental conditions were not found to be satisfactory, or because the compounds showed no characteristic ultraviolet absorbance. In many instances concentrations ranging from 500 to 1,000 ppm were required. Methods have been reported in the literature for some of these compounds (18-25). These compounds include:
Group B
|
Group E
|
Rescinnamine
|
Oxonamide
|
Alseroxylon
|
Group F
|
Group C
|
Methylphenidate hydrochloride
|
Captodiamine hydrochloride
|
Ethchlorvynol
|
Group D
|
Betazole
|
Meprobamate
|
Compound
|
Conc ppm
|
λmax mμ.
|
E 1 ppm 1 cm
|
λmin cmμ
|
E 1 ppm 1 cm
|
Compound
|
Conc ppm
|
λmax mμ.
|
E 1 ppm 1 cm
|
λmin cmμ
|
E 1 ppm 1 cm
|
Group A. Phenothiazine derivatives
|
Group B. Reserpine and related alkaloids
|
||||||||||
Promazine hydrochloride
|
10 | 253 |
.093
|
221 |
.023
|
Reserpine (Lilly)
|
10 | 218 |
.064
|
245 |
.008
|
303 |
.013
|
275 |
.005
|
270 |
.019
|
||||||
Promethazine hydrochloride
|
10 | 251 |
.089
|
221 |
.025
|
Reserpine (Ciba)
|
10 | 218 |
.062
|
246 |
.008
|
300 |
.011
|
274 |
.004
|
569 |
.018
|
||||||
Ethopropazine hydrochloride
|
10 | 251 |
.079
|
220 |
.021
|
Reserpine (Panray)
|
10 | 219 |
.066
|
245 |
.009
|
299 |
.010
|
275 |
.004
|
269 |
.019
|
||||||
Trimeprazine tartrate
|
10 | 253 |
.075
|
222 |
.020
|
Deserpidine
|
10 | 220 |
.099
|
243 |
.010
|
302 |
.010
|
277 |
.004
|
272 |
.030
|
||||||
Pyrathiazine hydrochloride
|
10 | 251 |
.096
|
221 |
.028
|
||||||
300 |
.012
|
274 |
.005
|
Group C. Diphenyl methane derivatives
|
|||||||
Chlorpromazine hydrochloride .
|
10 | 255 |
.090
|
225 |
.029
|
Chlorcyclizine hydrochloride
|
10 | 230 |
.042.
|
219 |
.024
|
310 |
.011
|
277 |
.003
|
Hydroxyzine hydrochloride
|
10 | 230 |
.030
|
218 |
.017
|
||
Proclorperazine dihydrochloride
|
10 | 257 |
.076
|
225 |
.023
|
Meclizine hydrochloride
|
10 | 231 |
.029
|
223 |
.024
|
312 |
.010
|
280 |
.003
|
||||||||
Proclorperazine ethane disul
|
|||||||||||
Fonate
|
10 | 257 |
.060
|
226 |
.018
|
Group D. Substituted butanediols, propanediols
|
|||||
311 |
.008
|
280 |
.002
|
Phenaglycodol
|
10 | 221 |
.048
|
||||
Proclorperazine dimaleate
|
10 | 257 |
.059
|
235 |
.028
|
Mephenesin | 10 | 271 |
.009
|
||
309 |
.007
|
281 |
.003
|
||||||||
Perphenazine
|
10 | 257 |
.053
|
225 |
.016
|
||||||
310 |
.007
|
280 |
.003
|
Group E. Ureides, amides, hydrazines and related compounds
|
|||||||
Thiopropazate dihydrochloride .
|
10 | 256 |
.033
|
227 |
.013
|
Phenelzine dihydrogen sulphate.
|
50 | 258 |
.008
|
228 |
.001
|
307 |
.006
|
280 |
.003
|
Iproniazid phosphate
|
10 | 264 |
.016
|
229 |
.008
|
||
Triflupromazine hydrochloride .
|
10 | 258 |
.077
|
224 |
.022
|
Nialamide | 10 | 265 |
.015
|
232 |
.009
|
306 |
.009
|
280 |
.003
|
Acetylcarbromal | 10 | 210 |
.048
|
-
|
-
|
||
Trifluoperazine dihydrochloride .
|
10 | 259 |
.063
|
225 |
.015
|
||||||
312 |
.007
|
281 |
.002
|
||||||||
Fluphenazine dihydrochloride
|
10 | 259 |
.052
|
224 |
.013
|
Group F. Miscellaneous compounds
|
|||||
305 |
.006
|
280 |
.002
|
||||||||
Methoxypromazine maleate
|
10 | 252 |
.061
|
230 |
.044
|
Thonzylamine hydrochloride
|
10 | 242 |
.072
|
||
305 |
.011
|
279 |
.004
|
276 |
.007
|
266 |
.005
|
||||
Mepazine hydrochloride
|
10 | 254 |
.083
|
222 |
.020
|
308 |
.008
|
290 |
.006
|
||
307 |
.011
|
275 |
.004
|
Pyrrobutamine phosphate
|
10 | 247 |
.016
|
283 |
.014
|
||
Thioridazine hydrochloride
|
<10
|
262 |
-
|
220 |
-
|
Chlormethazanone
|
10 | 228 |
.072
|
-
|
-
|
315 |
-
|
290 |
-
|
Imipramine hydrochloride
|
10 | 251 |
.023
|
231 |
.007
|
ULTRA-VIOLET SPECTRAL ABSORBANCE CURVES
Group A. Phenothiazine derivatives
PLATE 7 a PLATE 7 b
BULLETIN ON NARCOTICS l JANUARY-MARCH 1962 25
PLATE 8 a PLATE 8 b
26 BULLETIN ON NARCOTICS l JANUARY-MARCH 1962
Group A. Phenothiazine derivatives (continued)
PLATE 9 A PLATE 9 b
BULLETIN ON NARCOTICS l JANUARY-MARCH 1962 27
Group B. Reserpine and related alkaloids
PLATE 10 a PLATE 10 b
28 BULLETIN ON NARCOTICS l JANUARY-MARCH 1962
Group C. Diphenyl methane derivatives
PLATE 11 a PLATE 11 b
BULLETIN ON NARCOTICS l JANUARY-MARCH 1962 29
PLATE 12 a PLATE 12 b
Group D. Substituted butanediols, propanediols
|
Group F. Miscellaneous compounds
|
PLATE 13
a
|
PLATE 13
b
|
MephenesinPhenaglycodol
|
Thonzylamine hydrochloride Imipramine hydrochloride Pyrrobutamine phosphate Chlormethazanone
|
Group E. Ureides, amides, hydrazines and related compounds
PLATE14
a
|
PLATE14
b
|
β-phenylisopropyl hydrazine Phenelzine dihydrogen sulfate
|
AcetylcarbromalIproniazid phosphate
|
Group E. Ureides, amides, hydrazines and related componds (continued)
PLATE 15
a
|
PLATE15
b
|
EctylureaNialamide
|
GlutethimideIsocarboxazide
|
This work was supported by grants from the National Institutes of Health, Public Health Service, Department of Health, Education and Welfare (RG-4372) ,and the Research Committee of the University of California. Acknowledgment is made to thirty manufacturers of tranquillizing drugs for supplying samples of their products.
aStrong.
2Available from Globe Printing Co.,P.O. Box 968, San José, California.