الفهرس 
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Abstract
This study aimed to find out the possible interactions between dietary Oats marketed<in Egypt and the United Kingdom.
<The increasing attention towards healthy life style
caused many patients to shift towards healthy breakfast composed mainly of dietary Oats.
<Many studies highlighted the nutritional benefits of Oats due to their various phytoconstituents<e.g. β-glucan, carbohydrates, proteins and fats. Patients treated with oral
chronic drugs e.g. oral antidiabetics, antiepileptics, antithyroid may be advised to take the
Oatmeal as healthy diet.
<This concomitant administration of Oatmeal with oral chronic
drugs raised an important question towards the possible interactions at may occur between
Oat and the co administered drugs.
<The study aimed to point out the possible interaction
that may occur.
<Chapter one:
<This chapter aimed to characterize different Oat samples purchased from the
Egyptian markets and from those of the United Kingdom.
< Literature survey showed studies
performed on Oats to aid the food science fields.
<Most of the described methods in
literature lacked the correlation to the pharmaceutical field.
< In addition, all methods are
multistep complicated extractive methods for each phytochemical component.
haracterizations were performed with different analytical techniques and
rheological properties were studied as well.
<The analytical techniques used were Middle
Infra-red, near infra-red, Thin layer chromatography, High performance liquid
chromatography and Ultra violet spectroscopy.
Techniques were modified to aid the target of the thesis.
The middle and near Infra -
red techniques succeeded to characterize the samples of dietary Oats examined.
<The finger
prints for some phyto-constituents were similar to those obtained in the same technique
described in literature.
<Other analytical techniques confirmed that all samples of dietary Oats studied were
qualitatively the same.
< The high performance chromatographic methods were adopted
from literature for the separation of drugs suspected to interact with dietary Oats.
<HPLC
methods succeeded to separate between peaks of Oat and the examined drugs for clear
determination of the extent and percentage of interactions.
<Rheological studies were performed in two adsorption media: water and acidic
medium. Literature showed that the pharmacological effect of Oat in decreasing the level
of cholesterol and hyperglycemia was directly correlated to the viscosity of β-glucan which
is the main active constituent contributing to the beneficial pharmacological effect of Oat.
The rheological behavior was set as a factor contributing in the interaction with the coadministered
drugs.
The experiment was designed to find out the rheological behaviour of
the marketed Oat samples under study based on what was retrieved from literature.
The study was performed in neutral pH (water) and acidic pH (0.1 N HCl).
Samples
of dietary Oats were all examined under the same conditions at 37°C. The experiment was
performed with increasing speed up to 200 round per minute then the viscosity values were
recorded at decreasing speed. Samples of dietary Oats (A-D) were cooked in the same way
according to the labelled instructions stated on the pack to mimic the real behavior as the
patients administer Oats.
<Results revealed the all samples examined in 0.1 N HCl exhibited low viscosity values
with and without changing the viscosity values on increasing and decreasing speed of rotation.
<Rheological properties of samples examined in water were variable revealed that
cooked samples of dietary Oat (A-D) exhibited high viscosity values due to the
gelatinization of starch by the effect of heat in cooking the increased the resistance to flow.
<Chapter two:
<This chapter aimed to find out the possible interaction between samples of dietary Oat and
selected drugs.
Drugs selected on the basis of being chronically used and low or high dose potent
drugs.
< Two samples of Oat were selected for all adsorption studies (A) and (C).
Sample (A) was
in the form of raw Oat and sample (C) was in the form of biscuits.
< The in- vitro adsorption
studies were performed in water and 0.1 N HCL. Different categories of drugs were examined in
both conditions, anti-thyroid, anti- diabetic, anti -epileptic, bronchodilators and drugs for the
treatment of congestive heart failure.
<The in-vitro interaction was studied by allowing the drug to
digest in the selected medium either alone or in the presence of Oats.
< The temperature and the
time of the reaction were adjusted to mimic the physiological state as consumed by patients.
<HPLC methods reported in literature were used for analysis of drugs in both media to detect the
extent of adsorption. Many factors have been set to study the effect of these factors on the
adsorptive effect of Oat on drugs.
Factors studied were: increasing the volume of the medium to
detect the effect of volume on adsorption of the selected drugs and the particle size of the
adsorbent which is Oat.
<Largest and smallest ranges were studied for their effect on adsorption.
<Percentage of adsorption was calculated from the peak areas detected by the analytical
methods.an attempt was performed to study the effect of β-glucan on adsorption of drugs.
Marketed β-glucan capsules were purchased for the study.
Results revealed the complete adsorption of some drugs as a result of interaction with
Oats.
<The change of the peak intensities of drugs denoted the extent of adsorption on
dietary Oats.
Different factors examined on one selected drug (Glimepiride) showed no
difference in the exrtent of adsorption.
Studies performed on β-glucan denoted its
contribution in adsorption for some drugs e.g. Glibenclamide.
<Chapter three:
This chapter aimed to find out the percentage of availability of drugs under
conditions specialized in USP dissolution tests specialized in drug tablets monograph.
<Drugs were evaluated in absence and in presence of dietary Oats under the same
conditions.
<Two drug products were selected, Glimepiride hydrochloride and Drosperinone
as both drugs showed the complete adsorption in results of chapter two.
<The USP
dissolution tester was used to study the percentage of drug available at different time
intervals. Samples were withdrawn at different time intervals.
The test was terminated
according to the time stated in each monograph.
< The analysis of drugs was performed
using the analytical method adopted for their determination in the in-vitro studies
Calculations of the percentage of the available drug were performed as described in the
monograph of each drug product. The calculated percentages were used to construct the
dissolution rate profile.
<The profiles were used to compare the amount of available drug in
the dissolution medium under both conditions (in absence and in presence of dietary Oat).
<Results showed the significant decrease in the percentage of Drosperinone and
Glimepiride available in presence of Oat in the dissolution vessel.
< The drug was found to
complex with Oat within the first 15 minutes after running the dissolution tester :
< Chapter four:
<This study was performed to detect the possible interaction of dietary Oats with
selected oral antidiabetic drug products.
< In-Vitro adsorption studies in chapter two,
revealed possible adsorption of sulphonyl urea (glimepiride) tablets in contrast to
metformin Hydrochloride) tablets.
<They did not show adsorption. In-Vivo study on rats
was performed to confirm such interaction.
<The study was designed to be performed on
diabetic rat models. Hyperglycemia was induced with streptozotocin hydrochloride.
<Blood
glucose level was determined as a marker for the effectiveness of oral hypoglycemic drug
when administered alone or with dietary Oats.
< Rats were allowed to administer the drugs
after the intake of dietary Oats as their meals.
< Rats were grouped in 7 groups to perform
the comparison between groups, normo-glycemic, diabetic, glimepiride, metformin treated
and groups treated with both Oat and drugs.
<Results showed no effect of dietary Oat on the effectiveness of Metformin owing to
its large dose used (500 mg) and water solubility.
< However, the effectiveness of
glimepiride was decreased for rats treated with glimepiride tablets after being fed with
Oats.
<This group was compared to the group treated with the drug alone where glimepiride
showed significant decrease of the blood glucose level compared to the group treated with
Oat and glimepiride.