Pharmaceutical study on cinnarizine floating systems for oral sustained release drug delivery

In this study, cinnarizine was formulated in three different floating systems to control its release in gastric fluid. Four formulae containing different concentrations of Eudragit L100 [15-30% [w/w]] were prepared using sodium bicarbonate as CO2 generating agent. Three formulae containing methyl cellulose, hydroxypropyl methyl cellulose [HPMC] and sodium alginate of different viscosity grades [low, medium and high] were studied. Six formulae were also prepared using mixed polymers containing constant Eudragit L100 concentration and two concentrations of sodium alginate [of different viscosity grades]. All prepared formulae were evaluated through determining floating time, in vitro release rate of cinnarizine and in vivo bioavailability assessment of cinnarizine from selected floating systems. The obtained results in this study proved the effectiveness of the prepared cinnarizine floating systems in increasing its bioavailability. It also indicated the superiority of Eudragit L100 system over the alginate-cellulose system, which in turn has a higher bioavailability than the conventional cinnarizine capsule [197.57% and 176%, respectively]

Formulation and in-vivo investigation of riboflavin sustained release floating capsules

The aim of this work was to increase the bioavailability of riboflavin through the preparation of sustained release floating capsules using factorial design 23 technique. Seven floating capsules were prepared from granulated mixture of the drug with sodium bicarbonate, as CO2 generating agent, and one or more of three different polymers; namely, Eudragit L100, hydroxypropyl methyl cellulose [HPMC] and sodium alginate [according to a matrix table]. The effect of different polymers and their combinations on the in vitro release profile of the prepared floating riboflavin capsules was studied. Both capsules prepared with HPMC or mixture of HPMC and Eudragit L100 gave better drug release patterns. The mixed polymer formula [riboflavin/HPMC-Eudragit L100] was chosen for the in vivo evaluation in comparison with a control capsule using fluorimetric HPLC method for riboflavin analysis in the urine of five healthy volunteers. The initial excretion rates for the prepared floating formula were much higher than those of the conventional formula. The relative bioavailability of the prepared floating formula was 121% of the conventional formula, which indicated the superiority of the prepared floating capsule

Physico-chemical characterization of binary and ternary solid dispersions of praziquantel

In order to increase praziquantel [PZQ] dissolution, binary solid dispersions [SDs] containing 5, 10 and 20% w/w [drug/polymer] were prepared using water-soluble carriers as polyvinylpyrrolidone [PVPk90] and polyethyleneglycol-6000 [PEG 6000]. Ternary solid dispersions were prepared with incorporation of a non-ionic surfactant Tween 80 [Tw80] as a dissolution rate enhancer. The solubility and dissolution rate and extent were better from ternary systems than from binary systems. The physicochemical characteristics of the highest equilibrium solubility and dissolution behavior were determined by X- ray diffraction, differential scanning calorimetry [DSC], infrared spectroscopy [IR] and thin layer chromatography [TLC]

Therapeutic drug monitoring of insulin in Egyptian diabetic patients

The study involved 62 Egyptian diabetic patients who were receiving mixtard insulin HM 100 IU/ml in a dose that achieved euglycemic control. The study revealed that old age, male sex, obesity, cigarette smoking and cardiovascular disorders significantly increase serum insulin level. A linear correlation was shown between serum insulin level and insulin dose, but not with the duration of insulin therapy