Reducing Radiation Dermatitis Using a Film-forming Silicone Gel During Breast Radiotherapy: A Pilot Randomized-controlled Trial.

BACKGROUND/AIM: To evaluate whether topical use of a film-forming silicone gel (StrataXRT®) could reduce radiation dermatitis compared to a moisturizing cream (X-derm®) in patients receiving whole breast radiotherapy. PATIENTS AND METHODS: A total of 56 patients with breast cancer were randomized to use StrataXRT or X-derm. The severity of radiation dermatitis was graded using physiological skin parameters, clinician-assessed visual rating scales and patient-reported symptoms. Changes in these parameters from baseline to 4 weeks post-radiotherapy were evaluated every two weeks. RESULTS: Two-way repeated-measures ANOVA revealed different patterns of changes in the erythema index (F=3.609, p=0.008) and melanin index (F=3.475, p=0.015). The post hoc analysis demonstrated a significantly lower erythema index and melanin index in the patients allocated to the StrataXRT group. CONCLUSION: The use of StrataXRT can reduce radiation dermatitis with respect to objectively measured physiological skin parameters. The results of the present study will support the feasibility of conducting a larger randomized controlled trial.

Polystyrene bound silica monolith particles of reduced size as stationary phase of excellent separation efficiency in high performance liquid chromatograhy.

Ground silica monolith particles of quite smaller average size (2 µm) have been prepared by sol-gel process followed by soft grinding and calcination. Next a highly efficient chromatographic stationary phase has been prepared by reaction of those particles with (3-chloropropyl) trimethoxysilane followed by initiator attachment and modification of polystyrene by reversible addition-fragmentation chain transfer polymerization. The resultant phase of ca 3 µm particle size was packed in micro-columns (1.0 mm × 300 mm & 1.0 mm × 150 mm) to show the separation efficiencies as high as 67,600 and 35,500 plates/ column, respectively, for the separation of 5 small test molecules at a mobile phase flow rate of 25 µL/min. The 300 mm column shows a separation efficiency better than any of the commercially available conventional packed columns so far. Multiple shapes and high surface roughness as well as reduced particle size of the stationary phase of this study seem to contribute to such enhanced separation efficiency.

Paroxetine hydrochloride controlled release POLYOX matrix tablets: screening of formulation variables using Plackett-Burman screening design.

The aim of the present study was to screen the effects of the formulation variables - POLYOX molecular weight (X1), the ratio of POLYOX/Avicel PH102 (X2) and the amount of POLYOX and Avicel PH102 (X3), hardness (X4), HPMCP amount (X5), Eudragit L100 amount (X6), and citric acid amount (X7) - on the paroxetine hydrochloride release from POLYOX matrix tablet using the Plackett-Burman screening design. Paroxetine hydrochloride matrix tablets were prepared according to a 7-factor-12-run statistical model and subjected to a 8-h dissolution study in Tris buffer at pH 7.5. The regression results showed that POLYOX molecular weight (X1) and POLYOX/Avicel PH102 ratio (X2) had significantly influence on the drug release mechanism and drug release rate as main effects. Hardness (X4) had an insignificant effect on the drug release mechanism but a significant effect on the drug release rate. On the other hand, HPMCP, Eudragit L100 and citric acid had an insignificant effect on the both responses. The information obtained by screening design study can be expected to be useful for further formulation studies.

Development and optimization of a novel oral controlled delivery system for tamsulosin hydrochloride using response surface methodology.

The purpose of this study was to develop and optimize oral controlled-release formulations for tamsulosin hydrochloride using a combination of two cellulose ester derivatives, hydroxypropyl methylcellulose (HPMC) and hydroxypropyl methylcellulose phthalate (HPMCP), with Surelease as a coating material. A three-factor, three-level Box-Behnken design was used to prepare systematic model formulations, which were composed of three formulation variables, the content of HPMC (X(1)) and HPMCP (X(2)) and the coating level (X(3)), as independent variables. The response surface methodology (RSM) and multiple response optimization utilizing the polynomial equation were used to search for the optimal coating formulation with a specific release rate at different time intervals. The drug release percentages at 2, 3 and 5h were the target responses and were restricted to 15-30% (Y(1)), 50-65% (Y(2)) and 80-95% (Y(3)), respectively. The optimal coating formulation was achieved with 10% HPMC and 20% HPMCP at a coating level of 25%, and the observed responses coincided well with the predicted values from the RSM optimization technique. The drug release from pellets coated with the optimized formulation showed a controlled-release pattern (zero-order), in comparison with a commercial product (Harunal capsule). In conclusion, a novel, oral, controlled-release delivery system for tamsulosin hydrochloride was successfully developed by incorporating HPMC and HPMCP as coating additives into Surelease aqueous ethylcellulose dispersion.

Influence of water soluble additives and HPMCP on drug release from Surelease-coated pellets containing tamsulosin hydrochloride.

The objective of this study was to investigate the influence of various water-soluble additives and HPMCP as an enteric polymer into Surelease for the developement of oral controlled release system containg tamsulosin hydrochloride. The drug loaded pellets were coated with only Surelease or Surelease containing HPMC, PEG 4000, mannitol and HPMCP (20% w/w). In case of HPMC and PEG 4000 as additives into Surelease film, the rapid drug release was observed in pH 1.2 while the higher drug release was achieved by adding HPMCP into Surelease as well as by increasing the amount of HPMCP (10, 20, and 30% w/w) in pH 7.2. The incorporation of HPMCP into Surelease showed pH-denpendent drug release due to its pH-dependent nature. Therefore, the incorporation of HPMCP into Surelease based on aqueous coating formulation is an effective way to develop oral controlled release delivery systems containing tamsulosin hydrochloride.

Optimization of tamsulosin hydrochloride controlled release pellets coated with Surelease and neutralized HPMCP.

This study was to optimize the coating level in the development of controlled release pellets coated with Surelease and neutralized hydroxypropyl methylcellulose phthalate (HPMCP) by a computer optimization technique based on a response surface methodology utilizing polynomial equation. A full factorial 3(2) design was used for the optimization procedure with coating level (X(1)) and HPMCP content (X(2)) as the independent variables. The drug release percent at 2, 3 and 5 h were the target responses, which were restricted to 12-39% (Y(1)), 44-70% (Y(2)) and 70-100% (Y(3)), respectively. The quadratic model was well fitted to the data, and the resulting equation was used to predict the responses in the optimal region. It was shown that the optimized coating formulation was achieved at the ratio of 3:1 (Surelease: neutralized HPMCP) with 20% coating level. The optimized formulation showed release profiles and responses, which were close to predicted responses. Therefore, a full factorial 3(2) design and optimization technique can be successfully used in the development of optimized coating formulations based on Surelease and neutralized HPMCP to achieve a controlled release drug delivery system containing tamsulosin hydrochloride.

Development of megestrol acetate solid dispersion nanoparticles for enhanced oral delivery by using a supercritical antisolvent process.

In the present study, solid dispersion nanoparticles with a hydrophilic polymer and surfactant were developed using the supercritical antisolvent (SAS) process to improve the dissolution and oral absorption of megestrol acetate. The physicochemical properties of the megestrol acetate solid dispersion nanoparticles were characterized using scanning electron microscopy, differential scanning calorimetry, powder X-ray diffraction, and a particle-size analyzer. The dissolution and oral bioavailability of the nanoparticles were also evaluated in rats. The mean particle size of all solid dispersion nanoparticles that were prepared was <500 nm. Powder X-ray diffraction and differential scanning calorimetry measurements showed that megestrol acetate was present in an amorphous or molecular dispersion state within the solid dispersion nanoparticles. Hydroxypropylmethyl cellulose (HPMC) solid dispersion nanoparticles significantly increased the maximum dissolution when compared with polyvinylpyrrolidone K30 solid dispersion nanoparticles. The extent and rate of dissolution of megestrol acetate increased after the addition of a surfactant into the HPMC solid dispersion nanoparticles. The most effective surfactant was Ryoto sugar ester L1695, followed by D-α-tocopheryl polyethylene glycol 1000 succinate. In this study, the solid dispersion nanoparticles with a drug:HPMC:Ryoto sugar ester L1695 ratio of 1:2:1 showed >95% rapid dissolution within 30 minutes, in addition to good oral bioavailability, with approximately 4.0- and 5.5-fold higher area under the curve (0-24 hours) and maximum concentration, respectively, than raw megestrol acetate powder. These results suggest that the preparation of megestrol acetate solid dispersion nanoparticles using the supercritical antisolvent process is a promising approach to improve the dissolution and absorption properties of megestrol acetate.

Fabrication and evaluation of celecoxib microparticle surface modified by hydrophilic cellulose and surfactant.

This study was undertaken to improve the solubility and dissolution of a poorly water-soluble drug, celecoxib, by surface modification with a hydrophilic polymer and a surfactant by using a spray-drying technique. Based on the preliminary solubility tests, hydroxypropylmethyl cellulose (HPMC) and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) were selected as the polymer and the surfactant, respectively. A novel surface-modified celecoxib microparticle was successfully fabricated using a spray-drying process with water, HPMC, and TPGS, and without the use of an organic solvent. The physicochemical properties of the surface-modified celecoxib microparticle were characterized using scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), a particle size analyzer, and contact angle determination. The formulation with drug/HPMC/TPGS at the weight ratio of 1:0.5:1.5 was determined to be the most effective composition in the preparation of the surface-modified celecoxib microparticle, based on the results of wettability, solubility, and dissolution studies. We found that the surface modification of microparticles with HPMC and TPGS can be an effective formulation strategy for new dosage forms of poorly water-soluble active pharmaceutical ingredients (APIs) to provide higher solubility and dissolution.

Oral absorption of atorvastatin solid dispersion based on cellulose or pyrrolidone derivative polymers.

The objectives of this study were to investigate the effects of hydrophilic polymer on the supersaturation and oral absorption of amorphous atorvastatin calcium. Solid dispersions of atorvastatin calcium were prepared by a supercritical antisolvent (SAS) process. The solid dispersion with polyvinylpyrrolidone vinyl acetate (PVP VA64) achieved a higher degree and extent of supersaturation than the dispersions prepared with water-soluble polymers such as hydroxypropylmethyl cellulose (HPMC) and polyvinylpyrrolidone (PVP K30). The absorption of atorvastatin in rats was markedly increased when atorvastatin was orally administered in a PVP VA64 solid dispersion due to enhanced supersaturation and dissolution properties. Therefore, the oral absorption of atorvastatin calcium increased with the degree of supersaturation of solid dispersions prepared using an SAS process.

Supersaturatable formulations for the enhanced oral absorption of sirolimus.

The purpose of this study was to develop supersaturatable formulations for the enhanced solubility and oral absorption of sirolimus. Supersaturatable formulations of hydrophilic polymers and/or surfactants were screened by formulation screening, which is based on solvent casting. The solid dispersion particles in the optimized formulations were prepared by spray drying. The particles were characterized in vitro and in vivo. The most effective supersaturatable formulation found in the formulation screening process was hydroxypropylmethyl cellulose (HPMC)-D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), followed by HPMC-Sucroester. In addition, the supersaturated state generated from HPMC-TPGS and HPMC-Sucroester 15 particles prepared by spray drying significantly improved the oral absorption of sirolimus in rats. Based on the pharmacokinetic parameters and supporting in vitro supersaturated dissolution data, the enhanced supersaturation properties of sirolimus led to enhanced in vivo oral absorption. In addition, the experimental results from the formulation screening used in our study could be useful for enhancing the bioavailability of sirolimus in preformulation and formulation studies.

Optimized formulation of solid self-microemulsifying sirolimus delivery systems.

BACKGROUND: The aim of this study was to develop an optimized solid self-microemulsifying drug delivery system (SMEDDS) formulation for sirolimus to enhance its solubility, stability, and bioavailability. METHODS: Excipients used for enhancing the solubility and stability of sirolimus were screened. A phase-separation test, visual observation for emulsifying efficiency, and droplet size analysis were performed. Ternary phase diagrams were constructed to optimize the liquid SMEDDS formulation. The selected liquid SMEDDS formulations were prepared into solid form. The dissolution profiles and pharmacokinetic profiles in rats were analyzed. RESULTS: In the results of the oil and cosolvent screening studies, Capryol™ Propylene glycol monocapry late (PGMC) and glycofurol exhibited the highest solubility of all oils and cosolvents, respectively. In the surfactant screening test, D-α-tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS) was determined to be the most effective stabilizer of sirolimus in pH 1.2 simulated gastric fluids. The optimal formulation determined by the construction of ternary phase diagrams was the T32 (Capryol™ PGMC:glycofurol:vitamin E TPGS = 30:30:40 weight ratio) formulation with a mean droplet size of 108.2 ± 11.4 nm. The solid SMEDDS formulations were prepared with Sucroester 15 and mannitol. The droplet size of the reconstituted solid SMEDDS showed no significant difference compared with the liquid SMEDDS. In the dissolution study, the release amounts of sirolimus from the SMEDDS formulation were significantly higher than the raw sirolimus powder. In addition, the solid SMEDDS formulation was in a more stable state than liquid SMEDDS in pH 1.2 simulated gastric fluids. The results of the pharmacokinetic study indicate that the SMEDDS formulation shows significantly greater bioavailability than the raw sirolimus powder or commercial product (Rapamune® oral solution). CONCLUSION: The results of this study suggest the potential use of a solid SMEDDS formulation for the delivery of poorly water-soluble drugs, such as sirolimus, through oral administration.

Enhanced bioavailability of sirolimus via preparation of solid dispersion nanoparticles using a supercritical antisolvent process.

BACKGROUND: The aim of this study was to improve the physicochemical properties and bioavailability of poorly water-soluble sirolimus via preparation of a solid dispersion of nanoparticles using a supercritical antisolvent (SAS) process. METHODS: First, excipients for enhancing the stability and solubility of sirolimus were screened. Second, using the SAS process, solid dispersions of sirolimus-polyvinylpyrrolidone (PVP) K30 nanoparticles were prepared with or without surfactants such as sodium lauryl sulfate (SLS), tocopheryl propylene glycol succinate, Sucroester 15, Gelucire 50/13, and Myrj 52. A mean particle size of approximately 250 nm was obtained for PVP K30-sirolimus nanoparticles. Solid state characterization, kinetic solubility, powder dissolution, stability, and pharmacokinetics were analyzed in rats. RESULTS: X-ray diffraction, differential scanning calorimetry, and high-pressure liquid chromatography indicated that sirolimus existed in an anhydrous amorphous form within a solid dispersion of nanoparticles and that no degradation occurred after SAS processing. The improved supersaturation and dissolution of sirolimus as a solid dispersion of nanoparticles appeared to be well correlated with enhanced bioavailability of oral sirolimus in rats. With oral administration of a solid dispersion of PVP K30-SLS-sirolimus nanoparticles, the peak concentration and AUC(0→12h) of sirolimus were increased by approximately 18.3-fold and 15.2-fold, respectively. CONCLUSION: The results of this study suggest that preparation of PVP K30-sirolimus-surfactant nanoparticles using the SAS process may be a promising approach for improving the bioavailability of sirolimus.

pH-independent sustained release matrix tablet containing doxazosin mesylate: effect of citric acid.

The aim of this study was to develop a pH-independent sustained release matrix tablets of doxazosin mesylate. The matrix tablets were prepared by direct compression technique using polyethylene oxide, sodium alginate and citric acid as a pH modifier. Formulations were evaluated for an in vitro drug release study, erosion study, and the microenvironmental pH was studied using the pH indicator methyl red. For formulations without citric acid, the extent and rate of drug release in simulated gastric fluid were much higher than those in simulated intestinal fluid. By adding the citric acid, the drug release rate in simulated intestinal fluid was increased, and microenvironmental pH values within the tablets were maintained at low pH during drug release. Furthermore, drug release from the matrix tablet containing 20% w/w citric acid was comparable to that from a commercial product, Cardura® XL, and a pH-independent release could be achieved. Therefore, the incorporation of citric acid as a pH modifier to Polyethylene oxide-sodium alginate matrix tablets effectively produced pH-independent doxazosin mesylate release profiles.

Enhanced dissolution of megestrol acetate microcrystals prepared by antisolvent precipitation process using hydrophilic additives.

Microcrystals of megestrol acetate (MA), a poorly water-soluble drug, were successfully prepared using an antisolvent precipitation technique for improving the dissolution rate. The effective hydrophilic polymers and surfactants used were screened for their abilities to produce smaller particle sizes. Raw micronized MA and processed MA microcrystals were ranked by the Student-Newman-Keuls test in order of increasing particle size and SPAN values as follows: processed MA microcrystals in the presence of polymer and surfactant (mean diameter 1048nm)

The effect of sodium alginate on physical and dissolution properties of Surelease-matrix pellets prepared by a novel pelletizer.

The aim of this study was to investigate the effect of sodium alginate on the physical and dissolution properties of Surelease-matrix pellets prepared by a novel pelletizer-equipped piston extruder and double-arm counter-rotating rollers. The mean values of the shape factor (e(R)) and the aspect ratio of Surelease-matrix pellets were 0.615-0.625 and 1.06-1.070, respectively, indicating good sphericity of the pellets. The drug release rate increased as the amount of sodium alginate increased due to hydration, swelling, and erosion within the Surelease-matrix pellets. In addition, the porosity of pellets also increased with increasing sodium alginate content. The results of this study show that sodium alginate has a greater effect on the drug release rate than the drug release mechanism within the Surelease-matrix for sparingly water-soluble drug, such as tamsulosin hydrochloride.