STABILITY STUDIES AND INFLUENCE OF A LOW-FAT MEAL ON THE PHARMACOKINETIC AND BIOAVAILABILITY OF NIFEDIPINE IN HEALTHY VOLUNTEERS
STABILITY STUDIES AND INFLUENCE OF A LOW-FAT MEAL ON THE PHARMACOKINETIC AND BIOAVAILABILITY OF NIFEDIPINE IN HEALTHY VOLUNTEERS
No Thumbnail Available
Date
1991-09
Authors
SUNDAY, OLAWALE OKENIYI
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Identification tests for nifedipine based on the
thin-layer chromatography and melting point were carried
out on the three brands of nifedipine employed in this
study as specified in the B.P. (1988) addendum (1990).
The results obtained were in conformity with the B.P.
1988 specifications under identification tests for
nifedipine. The presence of nifedipine in the tablets
was examined by running the ultra-violet absorption
spectrum of the reference nifedipine and comparing it
with the U.V. spectra of the three brands of nifedipine
samples. The spectra exhibited maxima which were at
the same wavelength.
HPLC and UV methods of chemical assay were also
employed to determine the total drug content for the
three brands. The results complied favourably with the
stated amount in the B.P. 1988 for nifedipine content
(98.00 - 102.0C%).
The influence of day-light, fluorescent light, red-light,
temperature and ultraviolet irradiation on the stability
of nifedipine tablets and solution was evaluated. HPLC
method for estimating drug content in tablet dosage
forms was employed. Stability test of nifedipine
solution in methanol showed loss of drug content and
decomposition when exposed to day-light, fluorescent
and ultraviolet irradiation while there was no significant
decomposition nor loss of drug content under
red-light and elevated temperature up to 50 C.
Stability test carried out on nifedipine tablets showed
no loss of drug content, decomposition nor colour
change, indicating the stability of nifedipine tablets
under all the conditions of irradiation.
Dissolution rate profiles of three different
brands of nifedipine tablets in 0.1M methanolic-hydrochloric
acid was ingestigated by means of B.P. 1988 rotating
basket method. The drugs showed similarities in their
respective dissolution rate profiles. Total release
of the active ingredient for the three brands was
obtained in less than 30 minutes.
Disintegration time test was carried out on the
three brands of nifedipine tablets (S, 0, and K).
There was no considerable variation in their disintegration
times. The times taken for the three brands to
disintegrate was less than 8 minutes. They all passed
the official requirement of 15 minutes for tablet
disintegration.
Invivo bioavailability studies was carried out in
healthy human subjects in fasting and non-fasting states.
A simple, reliable and rapid HPLC method of nifedipine
estimation proceeded by an extraction technique was
employed for the determination of plasma and saliva
nifedipine levels, pharmacokinetic parameters for
plasma and saliva nifedipine samples were generated by
computer application.
Description
A THESIS SUBMITTED TO THE POSTGRADUATE SCHOOL,
AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL
FULFILLMENT OF THE REQUIREMENTS FOR THE
AWARD OF THE DEGREE OF MASTER OF
SCIENCE IN PHARMACEUTICAL CHEMISTRY.
DEPARTMENT OF PHARMACEUTICAL AND MEDICINAL CHEMISTRY,
FACULTY OF PHARMACEUTICAL SCIENCES,
AHMADU BELLO UNIVERSITY,
ZARIA, NIGERIA.
SEPTEMBER, 1991.
Keywords
STABILITY STUDIES,, INFLUENCE,, LOW-FAT MEAL,, PHARMACOKINETIC,, BIOAVAILABILITY,, NIFEDIPINE,, HEALTHY VOLUNTEERS