الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 220 |  |  |
| | | from | 220 | | |
Abstract
Contains the introduction which includes two parts: the first part
gives an idea about an active inhibitor of the angiotensin converting
enzyme (ACE), which has been widely used for the treatment of
hypertensive diseases. A detailed discussion about the definitions, action
and indications, metabolism and pharmacokinetics, chemical structures
and chemical names, characters of the studied drugs (captopril,
amlodipine besylate, diltiazem Hel, atenolol, lisinopril dihydrate and
enalapril maleate) are given. The second part gives a literature survey of
the previous studies for the analysis of the studied drugs including
spectrophotometric, spectrofluorimetric, titrimetric, physicochemical,
electro-analytical and chromatographic methods.
Chapterll
Contains the experimental part which includes apparatus used for
measurement and procedures for the preparation of drug and reagent
solutions. It also contains the proposed spectrophotometric methods for
determination of the studied drugs in pure and in dosage forms. Also, it
contains pharmacopoeial and official methods for analysis of the studied
drugs.
Chapter III
Contains the results and discussion which include six parts, each
part includes spectrophotometric procedure for determination of each
drug using KMn04 as oxidant. The proposed methods are based on
oxidation of the studied drug by KMn04 and determination of the
unreacted KMn04 by measuring the decrease in absorbance of different
dyes (methylene blue, acid blue 74, acid red 73, acid red 27 and acid
orange 7). The experimental variables are investigated.
1. Effect of potassium permanganate concentration
2-Effect of sulphoric acid concentration.
3-Effect of time and temperature.
4-Effect of sequence of additions.
5-Effect of dye concentration.
Beer’s law is obeyed in the concentration ranges (0.4-12.5, 0.3-10,
0.5-11,0.4-8.3 and 0.5-9.3 ~g ml”), (1.0-24, 0.9-22, 1.2-26,0.9-12.8 and
1.0-14 ug mrl), (0.7-10, 0.6-7.5, 0.5-13, 0.4-6.4 and 0.4-6.3 Ilg ml”),
(0.3-5.0, 0.2-4.4,0.2-3.9,0.1-3.6, and 0.3-6.0 ug mr1
), (0.5-10, 0.3-7.0,
0.5-9.0,0.4-6.1 and 0.4-7.2Ilg ml”) and (0.8-15.2, 0.7-11, 0.7-12, 0.5-7.6
and 0.6-9.5 ug mr1 ) for CAP, ADB, DIL, ATL, LIS and ENM, using
MB, AB, AR, AM and AO dyes, respectively. For more accurate results,
Ringbom optimum concentration ranges are determined. The apparent
molar absorptivity, Sandell sensitivity, detection and quantitation limits
are calculated. The stoichiometric ratios [O]/[Dye] are established using
the molar ratio method which found to be (1.0:0.4, 1.0:1.79, 1.0:0.7,
1.0:1.41 and 1.0:1.41), (1.0:0.4, 1.0:1.59, 1.0:0.7, 1.0:1.57 and 1.0:1.41),
(1.0:0.28, 1.0:1.41, 1:1.0, 1.0:1.2 and 1.0:1.41), (1.0:0.28, 1.0: 1.41,
1.0:1.1, 1.0:1.49 and 1.0:1.59), (1.0:0.3, 1.0:1.59, 1.0:0.8, 1.0:1.2 and
1.0:1.2) and (1.0:0.3, 1.0:1.59, 1.0:1.0, 1.0:1.2 and 1.0:1.59) for CAP,
ADB, DIL, ATL, LIS and ENM to KMn04 using MB, AB, AR, AM and
AG, respectively.
~7
~~
The stoichiometric ratios of the studied drugs with KMn04 are
established using the molar ratio method which found to be (1.0:0.8,
1.0:1.0, 1.0:0.9, 1.0:1.2 and 1.0:1.1), (1.0:0.56, 1.0:1.0, 1.0:0.56, 1.0:2.27
and 1.0:1.43), (1.0:1.11, 1.0:2.38, 1:2.0, 1.0:2.5 and 1.0:3.33), (1.0:2.56,
1.0:0.56, 1.0:2.5, 1.0:3.03 and 1.0:2.27), (1.0: 1.54, 1.0:2.27, 1.0:2.23,
1.0:3.13 and 1.0:2.44) and (1.0:1.67, 1.0:1.67, 1.0:1.3, 1.0:2.7 and
1.0:2.13) for CAP, ADB, DIL, ATL, LIS and ENM to KMn04 using Mfl,
AB, AR, AM and AO, respectively. In order to determine the accuracy
and precision of the proposed methods, solutions containing three
different concentrations of the studied drugs are prepared and analyzed in
six replicates. The recovery, the relative standard deviation, the relative
error and the confidence limits are calculated. The proposed methods are
successfully applied to determine the studied drugs in the pure and in
their dosage forms. The results obtained are compared statistically by
Student’s t-test (for accuracy) and variance ratio F-test (for precision)
with the official methods at 95% confidence level. The results showed
that the t- and F- values are less than the critical tabulated value
indicating that there is no significant difference between the proposed and
official methods. Thus the proposed spectrophotometric methods can
applied in routine analysis for determination of the studied drugs in pure
and in dosage forms. The results obtained from potentiometric indicated
that pK (2.5,4.1,6.67 and 10.11), (3.0 and 5.34), (3.63), (4.1) and (9.55)
for LIS, ENM, CAP, ADB and ATL, respectively. The free energy
changes LlG were calculated for these drugs, LIS (19.02,31.19,59.75 and
76.92), ENM (22.82 and 40.63), CAP (27.61), ADB (31.19) and ATL
(72.66) k J mol”,