Preparation and physicochemical characterization of solid dispersions of piroxicam with phospholipids

Solid dispersions of piroxicam with dimyristoylphosphatidylcholine [DMPC], dipalmitoylphosphatidylcholine [DSPC] and distearoylphosphatidylcholine [DSPC] in ratios of 20:1, 10:1 and 5:1 [drug-to-phospholipids w/w], were prepared by the solvent evaporation method. Coprecipitation was done from a chloroform solution of the appropriate quantities of piroxicam and each phospholipid according to the previously mentioned w/w ratios. The physicochemical characteristics of piroxicam-phospholipids coprecipitates were evaluated using differential scanning calorimetric analysis [DSC], X- ray diffraction analysis [XRD] and Fourier transform infrared analysis [FTlR]. Results were compared with the pure drug and the corresponding physical mixtures in the same weight ratios

Enhancement of dissolution and bioavailability of firoxicam via solid dispersion with phospholipids

In this work physical mixtures [PMs] and coprecipitates [COPPTs] of piroxicam [PIR] with each of L-alpha-dimyristoylphosphatidylcholine [DPPC] and L-alpha-distearoylphosphatidycholine [DSPC] in ratios of 20:1, 10:1 and 5:1 [drug-to-phospholipids w/w] were prepared. The effect of the method of preparation, the type of phospholipids [PL] and the drug-to-PL w/w ratios on the rate and extent of dissolution of PIR was investigated. The effect of the previously mentioned factors on the dissolution efficiency [DE%] was analyzed using two-way analysis of variance [ANOVA]. The most significant effect on the dissolution rate and extent was due to the method of preparation followed by the drug-to-PL ratio and finally the PL type. All PIR-PL systems improved the dissolution rate of piroxicam, but coprecipitates of 5:1 w/w ratio showed the superior effect on the drug dissolution profile

Evaluation and tableting characterization of spironolactone-B-cyclodextrin complex prepared by double compression technique

In this study, double compression technique [slugging] was evaluated to prepare SP-BCD complex. The prepared complex was evaluated by infrared [IR] and X-ray diffraction and compared with solid state complexes prepared from aqueous solution and partitioning technique. The SP-BCD powders were formulated into tablets and evaluated for their physicochemical properties. The aqueous solubility of SP from the prepared complexes and physical mixtures was found to be similar. The IR and X-ray diffraction studies of SP-BCD slugs indicated the presence of a mixture of amorphous, crystalline and inclusion complex. The tablet properties showed variations in hardness and disintegration time values. The dissolution rate of SP from tablets containing slugs was similar to those containing the other SP-BC complexes, while tablets prepared without BCD showed a very slow dissolution rate

Sustained release of diclofenac sodium form dry adsorbed emulsions

Sustained release W/O dry adsorbed emulsions containing diclofenac sodium were prepared. The effect of particle size, different emulsifying agents and various hydrophilic adsorbents on the sustained release characteristics of diclofenac sodium was studied. The drug release from dry adsorbed emulsions prepared with calcium stearate was slower than those prepared with Span 60. The effect of hydrophilic adsorbents on the drug release was found to be in the following order: Avical PH 101 > Aerosil 200 > Avicel RC-591. The release kinetics from the prepared particles showed that no one model was able adequately to describe the release situation. In vivo studies using human volunteers revealed a sustained release action up to 18 hours

Use of factorial design for the evaluation of the chemical stability of aspirin tablets

A factorial experimental design of type N = 2 3 was applied to predict the chemical stability of aspirin tablets directly compressed with sucrose-based vehicles [DiPac, Nu-Tab and Sugartab] and Avicel under 4 sets of storage conditions, 25% and 95% RH at two temperature levels [20C and 45C]. Tablets prepared by wet granulation technique were also employed for comparison. The quantitative factors were the temperature, relative humidity and time. The type of the vehicle used is only a qualitative factor. Tablets prepared with Avicel and those prepared by wet granulation technique gave complete measurable stability data under the selected storage conditions. The validity of the derived regression equations was verified by the experimental data of the classical design of experiments and the t50 values. Good agreement between the experimental and predicted data was obtained. Regression equations for the stability of tablets prepared with sucrose-based vehicles were not available due to their deformation under the selected storage conditions. The results of this investigation indicated that factorial design can have utility in predicting the chemical stability and expiry date of tablets in a short time and with less cost of experimentation

Formulation and ocular disposition of bromhexine hydrochloride ophthalmic preparations

Bromhexine hydrochloride [BH] a mucolytic agent was formulated in ophthalmic solutions, gels and ointments to be applied topically in the eyes to increase the mucus secretion in case of in flammation and keratoconjunctivitis. The effect of different ophthalmic vehicles, used in these formulation, on the in vitro release and ocular disposition of the drug in rabbit's eye has been studied. The results obtained revealed that, gel formulations [poloxamer 407 and sodium carboxymethylcellulose were superior to all other formulations for improving the ocular bioavailability of the drug. In case of ophthalmic solutions, the peak the time was attained after one hour while the peak level was elevated in the presence of 1% methylcellulose or polyvinyl alcohol. Semisolid vehicles, gels and ointments, exhibited a sustained activity of BH as the peak time was attained after two and three hours, respectively. Highly significant in vitro-in vivo correlations existed

Chemical stability of thiamine hydrochloride and ferrous fumarate in tablets prepared by direct and wet granulation techniques

The chemical stability of thiamine hydrochloride and ferrous fumarate in tablets prepared by direct granulation technique using Span 40, stearic acid or PEG 6000 as granulating agents were studied in comparison with those prepared by wet granulation technique. Batches of tablets that showed good physical and mechanical properties were selected for this study. The stability testing was carried out at 52% and 95% relative humidity at two temperature levels 25 and 45°C. The results obtained revealed that, the rate of degradation of either thiamine hydrochloride or ferrous fumarate was increased as the relative humidity and temperature were increased. In case of thiamine hydrochloride tablets, the highest stability data were obtained from tablets prepared with stearic acid followed by those prepared with PEG 6000. In case of ferrous fumarate the highest stability data were obtained from tablets prepared with stearic acid or Span 40. The degradation pathway of both drugs was found to follow the first order kinetics

Application of factorial design of experiments to predict the chemical stability of ferrous fumarate and thiamine hydrochloride tablets

In this-investigation factorial design of experiment of the type N = 2 [3]was applied to predict the chemical stability of ferrous fumarate and thiamine 'hydro chloride in tablets prepared by direct and wet granulation techniques, using Span 40, stearic acid and PEG 6000 as granulating agents. The quantitative factors were the temperature, humidity and time, corresponding to the accelerated storage conditions which are 52% and 95% relative humidity at two temperature levels [25 and 42 C]. The effect of the three operating factors and their interactions on the stability of both drugs as well as the derivation of impervical, regression equations were determined. The derived regression equations have the ability to predict the chemical stability of ferrous fumarate and thiamine hydrochloride tablets at any particular conditions within the limits specified. In addition, the coefficients of the factors and their interactions were found to have negative signs, which indicated that the effect of each factor was dependent on the level of the other two factors. The obtained results revealed that, there was very good agreement between the predicted and the experimental data obtained from the classical design of the experiments, carried out under the specified storage conditions. The reaction rate constants and [90%] of ferrous fumarate and thiamine hydrochloride tablets determined from the regression equations were found to be parallel with those determined from the first order plots. These findings indicated that, with the help of factorial design of experiments it could be possible to predict the expiry date of such tablets in a short time and less cost of experimentation

Effect of stress storage conditions on the physical characteristics and dissolution profiles of thiamine hydrochloride and ferrous fumarate tablets

The aging of thiamine hydro a chloride and ferrous fumarate tablets prepared by direct and wet granulation technique using span 40, stearic acid or PEG 6000 as granulating agents were studied under four sets of storage conditions [52% and 95% relative humidity at 25 [grades] and 42 [grades] C]. The physical properties and dissolution profiles of the tablets were evaluated periodically over 6 months. The results obtained revealed that, there was a marked increase in tablet weight, friability and disintegration time; while a significant decrease in hardness and dissolution rate was observed in all tablet formulations under all the selected storage conditions. At 95% RH, thiamine hydrochloride tablets prepared with span 40 or PEG 6000 were swelled or completely deformed after 2 months. These results pointed out that the tested tablets should be protected from moderate and higher temperature and humidity in order to maintain acceptable product quality throughout their shelf life

Influence of microcapsule size on the bioavailability of acetylsalicylic acid

Preparation of ethylcellulose microcapsules containing ASA were achieved. Four microcapsule sizes were separated using standard sieves set. The percent release as well as the bioavailability of each size were studied to get a correlation between in-vitro and in-vivo drug availability. Larger size microcapsules were found to show a lower bio-availability when compared with smaller ones. The same was observed in-vitro. A good correlation between in-vitro and in-vivo data was noticed in testing the dissolution rate of microcapsules alter 15 and 30 min. with percent excretion of ASA after one hour