The present study aims to develop sustained release (SR) matrix tablets of methyldopa using
hydrophilic hydroxypropyl methylcellulose (HPMC), and to study the effect of some formulation
variables (HPMC concentration and viscosity grade, combination
with hydrophobic Ethylcellulose
(EC) in different ratio, binder and lubricants concentrations) on the properties of prepared tablets.
Matrix tablets were prepared by wet granulation method, and prepared granules and tablets were
subjected to suitable physiochemical studies. Drug release kinetics showed that drug release
mechanism for about all formulations was found to fit best to Higuchi model and drug release
mechanism was anomalous diffusion based on release exponent value. The in-vitro dissolution
studies showed that formulation F6 containing 15% of HPMC K100M and formulation F11
containing EC:HPMC K4M (5%:10%) were able to sustain the release of methyldopa up to 24 hours
so these two formulations were selected as suitable formulations.
The objective of the present study was to formulate methyldopa sustained release
matrix tablets using hydrophilic hydroxypropyl methylcellulose (HPMC) alone or in
combination with hydrophobic ethyl cellulose polymer(EC). Matrix tablets were prepare
d
by wet granulation method, and subjected to physiochemical studies. All formulations
showed physiochemical properties which appear to be in compliance with pharmacopeial
standards. The in-vitro dissolution studies showed that increase in concentration or
viscosity of HPMC polymer led to decrease in the rate of drug release decreased. The
results also revealed that Combination of HPMC K4M and EC slower drug release more
than using HPMC K4M alone. Drug release kinetics of about all formulations correspond
best to Korsemeyer-Peppas model and drug release mechanism was anomalous diffusion
based on release exponent value.
The Objective of this study was to prepare Paracetamol Microcapsules using Gelatin type A and Gum Arabic as a hydrophilic polymers. Microcapsules were prepared by complex Coacervation. Microencapsulation Yield (MEY) and microencapsulation efficacy (M
EE) were investigated with respond to three variables including: Ratio of core to wall material (2:1, 4:1, 6:1), Stirring Speed (200, 300, 400) rpm and Drying method (Air at room temperature, Oven at 26ºC). The results showed that increasing core to wall material leads to increase in both MEE & MEY. The same effect was obtained when increasing stirring speed. Finally the change in a way drying leads to unnoticeable change in both MEE & MEY. Optimum MEE & MEY were obtained when using 6:1 core to wall material, 400 rpm in both two ways of drying.
السلفاسالازين دواء يستخدم في علاج التهاب الكولون القرحي وداء كرون وهو مادة عديمة الانحلال عمليا في الماء
