Development of an
Optimised Losartan Potassium Press-Coated Tablets for
Chronotherapeutic Drug Delivery
K Latha*1, MU Uhumwangho2
SA Sunil3, MV Srikanth3 and KV
Ramana Murthy3
1
G. Pulla Reddy
College of Pharmacy, Mehidipatnam,Hyderabad,500 028,
India, 2Department of Pharmaceutics
and Pharmaceutical Technology, Faculty of Pharmacy,
University of Benin, Benin City 300001, Nigeria,
3University College of Pharmaceutical
Sciences, Andhra University, Visakhapatnam-530003,
India.
For correspondence:
E-mail:
lathakukatil@gmail.com
Received: 12
April 2011 Revised
accepted: 22
September 2011
Tropical
Journal of Pharmaceutical Research, Oct 2011;
10(5): 551-558
http://dx.doi.org/10.4314/tjpr.v10i5.3
Abstract
Purpose:
To develop an optimised press-coated tablets of losartan
potassium using an admixture of a hydrophilic polymer,
hydroxypropylmethylcellulose (HPMC) and microcrystalline
cellulose (MCC) in order to achieve a predetermined lag
time for chronotherapy.
Methods:
The press-coated tablets (PCT) containing losartan
potassium in the inner core were prepared by
compression-coating with HPMC 100KM alone and admixed
with MCC as the outer layer in different ratios. The
effect of the outer layer on the lag time of drug
release was investigated. The parameters determined were
tablet tensile strength, friability, drug content and in
vitro dissolution. The optimised formulation was further
characterized with Fourier-transform infrared
spectroscopy (FTIR) and powder X-ray diffractometry (PXRD)
to investigate any drug/excipient
modifications/interactions.
Results:
The tensile strength
values of all the PCT were between
1.12 and 1.23MNm-2
and friability was < 0.36 %. The release profile of the
press-coated tablet exhibited a distinct lag time before
burst release of losartan potassium. Lag time was
dependent on the ratio of HPMC/MCC in the outer shell.
The lag time was from 0.5 to 18.5 h and could be
modulated as it decreased as the amount of MCC in the
outer layer increased. There was no modification or
chemical interaction between the drug and the excipient.
Conclusion:
Formulation LPP2, with HPMC/MCC of (30:70) in the outer
shell and showing a predetermined lag time of 6 h prior
to burst release of the drug from the press-coated
tablet was taken as the optimized formulation.
Keywords:
Losartan potassium,
press-coated tablet, hydroxypropylmethylcellulose,
microcrystalline cellulose, Fourier-transform infrared
spectroscopy and powder X-ray diffraction.
