Product : Hypromellose Phthalate
Hypromellose Phthalate also known as HPMC-P or Hydroxy Propyl Methyl Cellulose Phthalate or Cellulose,2-hydroxypropyl methyl ether, phthalic acid Ester.
HPMC-P i.e. Hypromellose Phthalate has higher moisture barrier property. Thus less prone to hydrolysis due to humidity.
Different grades are available to correlate required pH dissolution in Intestine i.e. from pH 5.0 to pH 5.5. This is achieved by controlled Variation in phthalyl content. Two types of pH variations in solubilities are available. HP-55, HP-55S & HP-50. Selection of required Grade of HPMC-P is made according to the requirements of formulations. Grade HP-55S is a special type of HP-55 having difference in molecular Weight and higher simulated gastric fluid resistance and viscosity.
HP-55 is well recognized and applied as a general enteric coating agent, is well accepted in pharma industries.
HP-55S, due to its higher molecular weight and higher degree of Polymerization w.r.t. HP-55, has higher viscosity, higher mechanical Strength of film and higher resistance to simulated gastric fluid of coated Formulation.This gives less percentage use in coating for tablets,gives better Strength to fragile tablets or granules or pellets.
HP-50, can be used to dissolve the tablets at lower pH in duodenam (pH 5.0), first part of the small intestine.
All the grades are available in BP/USPNF/EP. It can also be made and Supplied as per other recognized pharmacopeia.
Advantages of film coating: