Abstract
Rheumatoid arthritis is an auto immune disease which requires chronotherapy as it
occurs during early morning. Tramadol hydrochloride (TH) is an analgesic drug, used
to treat rheumatoid arthritis. The aim of the present investigation was to develop
chronomodulated drug delivery system of tramadol hydrochloride such that it releases
the drug early in the morning, during which the symptoms of rheumatoid arthritis worsen.
To develop chronomodulated drug delivery system of TH, initially core tablets of TH
were prepared using three different supradisintegrants followed by coating with pH
dependent polymer of Eudragit S100. The prepared core tablets are evaluated for physical
parameters and an optimal system was identified. Further, coating composition of Eudragit
S100 was optimized and coating tablets of TH was prepared. The prepared coated tablets
were evaluated for weight variation, hardness, drug content and in vitro release studies
in 0.1N HCl, pH 6.8 phosphate buffer and pH 7.4 phosphate buffer. Formulation with
7.5% of coating solution (ES2) had shown a significant drug release after a lag time
of 3 h (in pH 6.8 medium), 6 h (in pH 6.8 medium) and 8 h (in pH 7.4 medium), respectively.
DSC studies revealed that no interaction between core and coated materials with drug
was observed. Thus, chronomodulated drug delivery system of TH was formulated and
assuming that if a tablet is administered around 9 pm to 10 pm, the drug release starts
after a lag time of 6 h i. e., around 3am to 4 am.
Key words
Tramadol hydrochloride - chronotherapy - core tablets - coating tablets - dissolution