Solubility and dissolution enhancement of flurbiprofen by solid dispersion using hydrophilic carriers

ABSTRACT The intent of the current work is to study the effect of polyethylene glycol 8000 and polyethylene glycol 10000 as hydrophilic carriers on dissolution behaviour of flurbiprofen. In the present study, solvent evaporation method was used to prepare flurbiprofen solid dispersions and evaluated for physico-chemical properties, drug-carrier compatibility studies and dissolution behaviour of drug. Solubility studies showed more solubility in higher pH values and formulations SD4 and SD8 were selected to prepare the fast dissolving tablets. FTIR and DSC study showed no interaction and drug was dispersed molecularly in hydrophilic carrier. XRD studies revealed that there was change in the crystallinity of the drug. The results of In vitro studies showed SD8 formulation confer significant improvement (p<0.05) in drug release, Q20 was 99.08±1.35% compared to conventional and marketed tablets (47.31±0.74% and 56.86±1.91%). The mean dissolution time (MDT) was reduced to 8.79 min compared to conventional and marketed tablets (25.76 and 22.22 min.) indicating faster drug release. The DE (% dissolution efficiency) was increased by 2.5 folds (61.63%) compared to conventional tablets (23.71%). From the results, it is evident that polyethylene glycol solid dispersions in less carrier ratio may enhance the solubility and there by improve the dissolution rate of flurbiprofen.

Formulation and Pharmacokinetic Evaluation of Polymeric Dispersions Containing Valsartan.

BACKGROUND: Valsartan exhibits poor aqueous solubility and dissolution rate limited absorption. The lower solubility in the upper part of gastrointestinal tract (pH-dependant solubility) where its absorption window exists further contributes to the low oral bioavailability of valsartan. OBJECTIVE: The present work was aimed to improve the in vivo pharmacokinetics of valsartan by preparing amorphous polymeric dispersions using Eudragit E 100 as carrier. Eudragit E 100 is a cationic polymer soluble in gastric fluid up to pH 5.0 and exhibits pH-dependent release. Hence, the dispersions prepared using Eudragit E 100 rapidly dissolves at lower pH presenting drug in molecularly dispersed and soluble form at its absorption site. METHODS: Polymeric solid dispersions were prepared in different drug-to-carrier ratios. The prepared dispersions were evaluated for drug-carrier interactions, solid-state transitions and drug-release properties with the help of Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and in vitro dissolution studies. The optimized formulation containing valsartan was tested in rats for bioavailability and pharmacokinetic parameters and compared with that of valsartan pure drug. RESULTS: The results from FTIR studies indicated no interactions between drug and excipients. DSC studies confirmed reduction in crystallinity of drug. The dissolution studies performed in 0.1 N HCl showed significant improvement (p < 0.05) in the dissolution of valsartan. In vivo pharmacokinetic studies showed 199 % relative bioavailability with significant improvement (p < 0.05) in area under the curve compared to valsartan pure drug. CONCLUSION: Eudragit E 100 can be used to improve the dissolution of drugs that show low solubility at lower pH and thereby enhancing the bioavailability.

Formulation and pharmacokinetics of gelucire solid dispersions of flurbiprofen.

CONTEXT: Development of solid dispersions is to improve the therapeutic efficacy by increasing the drug solubility, dissolution rate, bioavailability as well as to attain rapid onset of action. OBJECTIVE: The present research deals with the development of solid dispersions of flurbiprofen which is poorly water soluble to improve the solubility and dissolution rate using gelucires. MATERIALS AND METHODS: In this study, solid dispersions were prepared following solvent evaporation method using gelucire 44/14 and gelucire 50/13 as carriers in different ratios. Then the formulations were evaluated for different physical parameters, solubility studies, DSC, FTIR studies and in vitro dissolution studies to select the best formulation that shows rapid dissolution rate and finally subjected to pharmacokinetic studies. RESULTS AND DISCUSSION: From the in vitro dissolution study, formulation F3 showed the better improvement in solubility and dissolution rate. From the pharmacokinetic evaluation, the control tablets produced peak plasma concentration (Cmax) of 9140.84 ± 614.36 ng/ml at 3 h Tmax and solid dispersion tablets showed Cmax = 11 445.46 ± 149.23 ng/ml at 2 h Tmax. The area under the curve for the control and solid dispersion tablets was 31 495.16 ± 619.92 and 43 126.52 ± 688.89 ng h/ml and the mean resident time was 3.99 and 3.68 h, respectively. CONCLUSION: From the above results, it is concluded that the formulation of gelucire 44/14 solid dispersions is able to improve the solubility, dissolution rate as well as the absorption rate of flurbiprofen than pure form of drug.