Formulation optimization and in vitro evaluation for the gastro retentive tablets of Labetolol

Abstract

The controlled  gas tric  retention  of s olid dos age forms  may be achieved  by the mechanis ms   of  mucoadhes ion, flotation,   sedimentation,   expans ion,   modified   s hape s ystems ,   or   by   the   s imultaneous    adminis tration   of pharmacological   agent   that   delay gas tric   emptying.   Bas ed on   thes e  approaches , clas s ification of  floating drug   delivery  s ystems   (FDDS)   has  been  des cribed  in  detail. Floating     granules  we re  p re p a re d  by  us ing Dire c t  Compres s ion  technique.       The  oral  bioavailabilty  of Labetolol  has  been  reported  to  be  about  25%. Gas tric   floating   drug   delivery   is   one   approach   where  the  gas tro   intes tinal  res idence   time  is  prolonged becaus e  of  the  floating  behavior.  In  the  pres ent  study  the  formulations   were  prepared  by  us ing  different proportions    of    polymer.       The    prepared   formulations    were    evaluated   for    different   phys icochemical characteris tics  s uch as thicknes s  and diameter, drug content, weight variation,  hardnes s , friability.  The releas e c h a ra c t e ris t ic s  of  the  formulation  were  s tudied  in  in-vitro  conditions . The  IR s pectrum  of pure  drug  and drug-polymer  mixture  revealed  that  there  was  no interaction  between  polymer and drug. The prepared  floating tablet  is  indus trially  feas ible  method.  Bulk  dens ity  and  tapped  dens ity  s hown  good  packability  and  Ca rr’s index res ults  s hown  excellent  compres s ibility.  Formulation  F16  containing  combination  of Metalos e SR and Manucol was found to releas e a maximu m  of 97.2431%  at the 12th  hour.