Formulation development and dissolution rate enhancement of efavirenz by solid dispersion systems

Abstract

The aim of this study was to enhance the dissolution rate of efavirenz using solid dispersion systems (binary and ternary). A comparison between solvent and fusion method was also investigated. Solid dispersions of efavirenz were prepared using polyethylene glycol 8000, polyvinylpyrrolidone K30 alone and combination of both. Tween 80 was incorporated to obtain a ternary solid dispersion system. Dissolution tests were conducted and evaluated on the basis of cumulative percentage drug release and dissolution efficiency. Physicochemical characterizations of the solid dispersions were carried out using differential scanning calorimetric, powder X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. Dissolution was remarkably improved in both systems compared to pure efavirenz (P<0.05). An optimum ratio was identified at a drug:polymer of 1:10. Incorporation of Tween 80 to 1:10 formulations formed using solvent method showed further improvement in the dissolution rate. Physicochemical characterization results suggested that efavirenz existed in the amorphous form in all the solid dispersion systems providing evidence of improvement in dissolution. No statistically significant difference (P>0.05) in dissolution was observed between the two methods. Binary and ternary solid dispersion systems both have showed a significant improvement in the dissolution rate of efavirenz. Formulations with only polyvinylpyrrolidone K30 showed best dissolution profile and 1:10 was identified as an optimum drug-polymer weight ratio.

Toxicity nanoinsecticide based on clove essential oil against <i>Tribolium castaneum</i> (Herbst)

“…34) This polymer has characteristics: good solubility in many organic solvents, have a low melting point (below 65°C), low toxicity, able to dissolve some compounds, and could improve compound moisture. 35,36) The addition of a material (such as essential oil) or the fast cooling of the melted PEG could act as an inhibitor of crystallization resulting in a higher percentage of amorphous and imperfectly crystalline material; the amorphous character is common with polymeric molecules used as a carrier. 21) However, further evaluation is needed on the other biological activities, for example, evaluation of antifeedant and enzyme activity that plays a role in the toxicity process.…”

An Approach to Enhance Dissolution Rate of Tamoxifen Citrate

“…An X-ray diffractometer (Philips, UK) was used to record the powder XRD of TC, PEG-6000, β -CD, TC+PEG, TC+ β -CD, TC+PEG-6000+ β -CD, and solid dispersions. The scanning rate used was 5/min, and the diffraction angle (2 θ ) was 0–70 [21].…”

“…The samples of plasma were then stored at -80°C till analysis time. HPLC was used to analyze the plasma levels of TC in which the mobile phase was acetonitrile: methanol (85:15% v/v) which contained 0.02% triethylamine and enacted at a flow rate of 1.5 ml/ min [21]. To extract the drug from plasma, acetonitrile was added to each sample (1:4 volume) followed by a 30-second vortex and centrifugation at 4,000 rpm for 15 minutes.…”

Preparation and in vitro characterization of non-effervescent floating drug delivery system of poorly soluble drug, carvedilol phosphate

“…C-POL MG (1:4), C-POL MG (1:5) and C-POL MG (1:6) showed maximal cumulative drug release of 95.6, 95.4 and 94.6 %, respectively, with similar drug release patterns suggesting that the increasing of the drug-to-poloxamer ratio above 1:4 did not increase the release rate of the drug. This might be due to formation of a carrier layer around the drug particles, which may not allow the drug to come out of the dispersion (13). Formulation C-POL MG (1:4) was selected as the optimized batch to prepare tablets.…”