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

Formulation and evaluation of taste-masked oral disintegrating tablet containing tolterodine-loaded montmorillonite

Background and purpose

The present study aimed to obtain a taste-masked oral disintegrating tablet (ODT) containing tolterodine tartrate (TT) intercalated into montmorillonite (MMT).

Experimental approach

The TT-MMT hybrid was prepared by ion exchange reaction. The effect of the initial concentration of TT, MMT, temperature, and pH on the encapsulation efficiency (EE) % of the drug in MMT was evaluated. The selected TT-MMT hybrid was characterized by X-ray diffraction (XRD), Fourier transforms infrared (FTIR), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Then, the optimized TT-MMT hybrid was incorporated in the ODT prepared by direct compression method and taste-masking assessment performed by a human test panel.

Findings/Results

The EE% of TT was in the range of 22.67 to 71.06% in different formulations. It was found that increases in MMT concentration significantly increased EE%. DSC and XRD studies indicated that the TT was intercalated in the MMT interlayer space in an amorphous or molecular state. In-vitro release studies at pH 6.8 showed that the amount of the drug released from the TT-MMT hybrid was negligible for the first 3 min. The post-compression of ODT also showed satisfactory results in terms of friability, hardness, disintegration time, and taste.

Conclusion and implications

MMT-ODT could be a suitable vehicle for the taste masking of TT, with the potential for use in patients with swallowing problems.

Deriving valorization of phenolic compounds from olive oil by-products for food applications through microencapsulation approaches: a comprehensive review

Nowadays, olive oil consumption is correlated to many health benefits, essentially due to the presence of antioxidants, especially phenolic compounds, which fostered its intensive production worldwide. During olive oil extraction, through continuous or discontinuous processes, many olive oil by-products are generated. These by-products constitute an environmental problem regarding its management and disposal. They are phytotoxic and biotoxic due to their high content of phenolic compounds, presenting contrastingly relevant health benefits due to their potent radical scavenging activities. In the framework of the disposal and management of olive oil by-products, treatment, and valorization approaches are found. As currently, the majority of the valorization techniques applied have a null market value, alternative strategies for the obtainment of innovative products as fortified foods are being investigated. The recovery and valorization strategies of olive oil by-products may comprise extraction and further encapsulation of bioactive compounds, as an innovative valorization blueprint of phenolic compounds present in these by-products. The majority of phenolic compounds present in olive oil by-products possess limited application on the food industry since they are promptly amended by environmental factors like temperature, pH, and light. Consequently, they must be protected previously ending in the final formulation. Prior to foods fortification with phenolic-rich extracts obtained from olive oil by-products, they should be protected through microencapsulation approaches, allowing a sustained release of phenolic compounds in the fortified foods, without losing their physicochemical properties. The combined strategies of extraction and microencapsulation will contribute to promoting the sustainability of the olive oil sector and aid the food industry to obtain reinvented added-value products.

Development of a Resveratrol Nanosuspension Using the Antisolvent Precipitation Method without Solvent Removal, Based on a Quality by Design (QbD) Approach

The purpose of this study was to develop a resveratrol nanosuspension with enhanced oral bioavailability, based on an understanding of the formulation and process parameters of nanosuspensions and using a quality by design (QbD) approach. Particularly, the antisolvent method, which requires no solvent removal and no heating, is newly applied to prepare resveratrol nanosuspension. To ensure the quality of the resveratrol nanosuspensions, a quality target product profile (QTPP) was defined. The particle size (z-average, d90), zeta potential, and drug content parameters affecting the QTPP were selected as critical quality attributes (CQAs). The optimum composition obtained using a 3-factor, 3-level Box-Behnken design was as follows: polyvinylpyrrolidone vinyl acetate (10 mg/mL), polyvinylpyrrolidone K12 (5 mg/mL), sodium lauryl sulfate (1 mg/mL), and diethylene glycol monoethyl ether (DEGEE, 5% v/v) at a resveratrol concentration of 5 mg/mL. The initial particle size (z-average) was 46.3 nm and the zeta potential was -38.02 mV. The robustness of the antisolvent process using the optimized composition conditions was ensured by a full factorial design. The dissolution rate of the optimized resveratrol nanosuspension was significantly greater than that of the resveratrol raw material. An in vivo pharmacokinetic study in rats showed that the area under the plasma concentration versus time curve (AUC0-12h) and the maximum plasma concentration (Cmax) respectively, than those of the resveratrol raw material. Therefore, the prepara values of the resveratrol nanosuspension were approximately 1.6- and 5.7-fold higher,tion of a resveratrol nanosuspension using the QbD approach may be an effective strategy for the development of a new dosage form of resveratrol, with enhanced oral bioavailability.

Effects of ionic interactions on protein stability prediction using solid-state hydrogen deuterium exchange with mass spectrometry (ssHDX-MS)

Deuterium incorporation in solid-state hydrogen deuterium exchange with mass spectrometry (ssHDX-MS) has been correlated with protein aggregation on storage in sugar-based solid matrices. Here, the effects of sucrose, arginine and histidine buffer on the rate of aggregation of a lyophilized monoclonal antibody (mAb) were assessed using design of experiments (DoE) and response surface methodology. Lyophilized formulations were characterized using ssHDX-MS and Fourier transform infrared spectroscopy (ssFTIR) to assess potential correlation with stability in solid state. The samples were subjected to storage stability at 5 °C and stressed stability at 40 °C/75% RH for 6 months, and the aggregation rate was measured using size exclusion chromatography (SEC). Different levels of arginine had no significant effect on deuterium uptake in ssHDX-MS, although stability studies showed that aggregation rate decreased with increasing arginine concentration. Similarly, when histidine buffer was replaced with phosphate buffer at the same pH and molarity, ssHDX-MS showed no differences in deuterium uptake, but storage stability studies showed a significant increase in aggregation rate. The results suggest that proteins can be stabilized in amorphous solids by ionic interactions which ssHDX-MS does not detect, an important indication of the limitations of the method.

Pantoprazole Sodium Loaded Microballoons for the Systemic Approach: In Vitro and In Vivo Evaluation

Purpose: Various floating and pulsatile drug delivery systems suffer from variations in the gastric transit time affecting the bioavailability of drugs. The objective of the study was to develop Pantoprazole Sodium (PAN) microballoons that may prolong the gastric residence time and could enhance the drug bioavailability.

Methods: Microballoons were prepared using Eudragit^®L100 by adopting emulsion solvent diffusion method with non-effervescent approach, in vitro studies were performed and the in vivo evaluation was carried out employing ethanol induced ulceration method. Optimization and validation were carried out through Design Expert^® software.

Results: The results demonstrate an increase in percentage yield, buoyancy, encapsulation efficacy and swelling. Particles were in the size range 80-100 µm following zero order release pattern. SEM study revealed their rough surface with spherical shape, internal cavity and porous walls. DSC thermo gram confirms the encapsulation of drug in amorphous form. Significant anti ulcer activity was observed for the prepared microballoons. The calculated ulcer index and protection were 0.20±0.05 and 97.43 % respectively for LRS-O (optimized formulation).

Conclusion: This kind of pH dependent drug delivery may provide an efficient dosage regimen with enhanced patient compliance.

Tri-block co-polymer nanocarriers for enhancement of oral delivery of felodipine: preparation, in vitro characterization and ex vivo permeation

This study aimed to prepare, optimize and characterize novel felodipine-loaded polymeric nanomicelles, using a pluronic mixture of F127 and P123. Thin-film hydration method was adopted for the preparation of different polymeric nanomicelles (T1-T12) according to a 4¹.3¹ full factorial design. Factors studied were: Pluronic®:drug ratio (P:D ratio) (10, 20, 30 and 40 w/w) and percent of hydrophilic polymer (F127%) (33.33%, 50% and 66.67% w/w). Optimization criteria were to maximize transmittance percent (T%) and entrapment efficiency percent (EE%) and to minimize particle size (PS) and polydispersity index (PDI). The optimized formulation was further characterized by DSC, FTIR and ¹H NMR studies. It was also subjected to stability testing and ex vivo permeation using rabbit intestines. Spherical nanomicelles of particle size ranging from 26.18 to 87.54 nm were successfully obtained. The optimized formulation was found to be the already prepared formulation T12 (P:D ratio of 40 and 66.67% F127) with suitable T% and EE% of 95.12% and 91.75%, respectively. DSC, FTIR and ¹H NMR studies revealed felodipine (FLD) incorporation within T12 nanomicelles. T12 enhanced the ex vivo intestinal permeation of FLD when compared to a drug suspension and showed good stability. Therefore, pluronic nanomicelles could be promising for improved oral delivery of FLD.

Optimizing Prednisolone Loading into Distiller's Dried Grain Kafirin Microparticles, and In vitro Release for Oral Delivery

Kafirin microparticles have potential as colon-targeted delivery systems because of their ability to protect encapsulated material from digestive processes of the upper gastrointestinal tract (GIT). The aim was to optimize prednisolone loading into kafirin microparticles, and investigate their potential as an oral delivery system. Response surface methodology (RSM) was used to predict the optimal formulation of prednisolone loaded microparticles. Prednisolone release from the microparticles was measured in simulated conditions of the GIT. The RSM models were inadequate for predicting the relationship between starting quantities of kafirin and prednisolone, and prednisolone loading into microparticles. Compared to prednisolone released in the simulated gastric and small intestinal conditions, no additional drug release was observed in simulated colonic conditions. Hence, more insight into factors affecting drug loading into kafirin microparticles is required to improve the robustness of the RSM model. This present method of formulating prednisolone-loaded kafirin microparticles is unlikely to offer clinical benefits over commercially available dosage forms. Nevertheless, the overall amount of prednisolone released from the kafirin microparticles in conditions simulating the human GIT demonstrates their ability to prevent the release of entrapped core material. Further work developing the formulation methods may result in a delivery system that targets the lower GIT.

Design of experiments for microencapsulation applications: A review

Microencapsulation techniques have been intensively explored by many research sectors such as pharmaceutical and food industries. Microencapsulation allows to protect the active ingredient from the external environment, mask undesired flavours, a possible controlled release of compounds among others. The purpose of this review is to provide a background of design of experiments in microencapsulation research context. Optimization processes are required for an accurate research in these fields and therefore, the right implementation of micro-sized techniques at industrial scale. This article critically reviews the use of the response surface methodologies in pharmaceutical and food microencapsulation research areas. A survey of optimization procedures in the literature, in the last few years is also presented.

The effect of freeze-dried antibody concentrations on its stability in the presence of trehalose and hydroxypropyl-β-cyclodextrin: a Box-Behnken statistical design

The present study aimed at preparation and optimization of stable freeze-dried immunoglobulin G (IgG) applying proper amount of antibody with efficient combination of trehalose and hydroxypropyl-β-cyclodextrin (HPβCD). Response surface methodology was employed through a three-factor, three-level Box-Behnken design. Amounts of IgG (X₁), trehalose (X₂) and HPβCD (X₃) were independent variables. Aggregation following process (Y₁), after one month at 45 °C (Y₂), upon two month at 45 °C (Y₃) and beta-sheet content of IgG (Y₄) were determined as dependent variables. Results were fitted to quadratic models (except for beta-sheet content), describing the inherent relationship between main factors. Optimized formulation composed of 55.85 mg IgG, 52.51 mg trehalose and 16.01 mg HPβCD was prepared. The calculated responses of the optimized formulation were as follows: Y₁ = 0.19%, Y₂ = 0.78%, Y₃ = 1.88% and Y₄ = 68.60%, respectively. The thermal analysis confirmed the amorphous nature of optimum formulation and the integrity of IgG was shown to be favorably preserved. Validation of the optimization study demonstrated high degree of prognostic ability. The DOE study successfully predicted the optimum values of antibody as well as stabilizers for desirable process and storage stabilization of freeze-dried IgG.

Formulation of extended release cefpodoxime proxetil chitosan-alginate beads using quality by design approach

The purpose of this work was to develop and characterize chitosan-alginate beads for the extended delivery of cefpodoxime proxetil (CFP), to understand the impact of formulation and process parameters on the critical quality attributes (CQAs) using a quality-by-design approach. For this, a study was performed with various formulation and process parameters to determine their impact on CQAs of beads, which were determined to be time for 80% of the drug released (T80%), particle size, and encapsulation efficiency. The beads of CFP were optimized using a three-factor, three-level Box-Behnken design. A formulation comprising of 4.38% (w/v) alginate, 1.39% (w/v) chitosan and 6.82% (w/v) calcium chloride was found to fulfill requisites of an optimum formulation. In vitro release studies showed that the drug is released from the optimized formulation over a period of 24h in a sustained release manner, primarily by non-Fickian diffusion. The optimized formulation was characterized by DSC, FTIR, XRD and SEM analysis. Antimicrobial studies revealed that the release of the drug over 24h periods was above the minimum concentration required for inhibition of microbial growth. This research highlights the level of understanding that can be accomplished through a well designed study based on the approach of QbD.

Application of active layering and coating techniques in the development of a multiparticulate, controlled release dosage form of a high-dose, highly soluble drug

CONTEXT

The success of the development of controlled release, multilayered, multiparticulate dosage form of a high-dose, highly-soluble drug is dependent upon proper material and processing choices.

OBJECTIVE

To develop a controlled release dosage form of diltiazem hydrochloride using active layering and coating.

METHODS

Active layering was achieved by spraying a drug solution onto sugar cores using polyvinyl alcohol - polyethylene glycol as a binder. Layered pellets with highest loading and lowest binder content were coated using aqueous dispersions of polyvinyl acetate (PVAc). The effects of the plasticizer and curing on drug release were evaluated.

RESULTS AND DISCUSSION

The binder level had no effect on the process efficiency. Drug release from PVAc-coated pellets was slowed by increasing PVAc level. Plasticization slowed drug release in comparison to nonplasticized formulations. Curing affected drug release of nonplasticized formulations only. Protection against humidity was essential in stabilizing drug release under stability study conditions.

CONCLUSION

Materials and process used were suitable to face the challenge posed by the high dose of the water-soluble drug on the success of the formulation. The effects of the plasticizer, curing and ability of packaging to protect against elevated humidity on the performance of the studied system should be considered in development.

Feasibility of optimizing trimetazidine dihydrochloride release from controlled porosity osmotic pump tablets of directly compressed cores

The aim of this study was to develop and optimize Trimetazidine dihydrochloride (TM) controlled porosity osmotic pump (CPOP) tablets of directly compressed cores. A 2³ full factorial design was used to study the influence of three factors namely: PEG400 (10% and 25% based on coating polymer weight), coating level (10% and 20% of tablet core weight) and hole diameter (0 “no hole” and 1 mm). Other variables such as tablet cores, coating mixture of ethylcellulose (4%) and dibutylphthalate (2%) in 95% ethanol and pan coating conditions were kept constant. The responses studied (Y_i) were cumulative percentage released after 2 h (Q%_2h), 6 h (Q%_6h), 12 h (Q%_12h) and regression coefficient of release data fitted to zero order equation (RSQ_zero), for Y₁, Y₂, Y₃, and Y₄, respectively. Polynomial equations were used to study the influence of different factors on each response individually. Response surface methodology and multiple response optimization were used to search for an optimized formula. Response variables for the optimized formula were restricted to 10% ⩽ Y₁ ⩽ 20%, 40% ⩽ Y₂ ⩽ 60%, 80% ⩽ Y₃ ⩽ 100%, and Y₄ > 0.9. The statistical analysis of the results revealed that PEG400 had positive effects on Q%2h, Q%6h and Q%12h, hole diameter had positive effects on all responses and coating level had positive effect on Q%_6h, Q%_12h and negative effect on RSQ_zero. Full three factor interaction (3FI) equations were used for representation of all responses except Q%_2h which was represented by reduced (3FI) equation. Upon exploring the experimental space, no formula in the tested range could satisfy the required constraints. Thus, direct compression of TM cores was not suitable for formation of CPOP tablets. Preliminary trials of CPOP tablets with wet granulated cores were promising with an intact membrane for 12 h and high RSQ_zero. Further improvement of these formulations to optimize TM release will be done in further studies.

Optimization and characterization of gastroretentive floating drug delivery system using Box-Behnken design

CONTEXT

One among many strategies to prolong gastric residence time and improve local effect of the metronidazole in stomach to eradicate Helicobacter pylori in the treatment of peptic ulcer was floating drug delivery system particularly effervescent gastroretentive tablets.

OBJECTIVE

The objective of this study was to prepare and evaluate, effervescent floating drug delivery system of a model drug, metronidazole.

METHODS

Effervescent floating drug delivery tablets were prepared by wet granulation method. A three-factor, three levels Box-Behnken design was adopted for the optimization. The selected independent variables were amount of hydroxypropyl methylcellulose K 15M (X1), sodium carboxy methylcellulose (X2) and NaHCO3 (X3). The dependent variables were floating lag time (YFLT), cumulative percentage of metronidazole released at 6th h (Y6) and cumulative percentage of metronidazole released at 12th h (Y12). Physical properties, drug content, in vitro floating lag time, total floating time and drug release behavior were assessed.

RESULTS

YFLT range was found to be from 1.02 to 12.07 min. The ranges of other responses, Y6 and Y12 were 25.72 ± 2.85 to 77.14 ± 3.42 % and 65.47 ± 1.25 to 99.65 ± 2.28 %, respectively. Stability studies revealed that no significant change in in vitro floating lag time, total floating time and drug release behavior before and after storage.

CONCLUSION

It can be concluded that a combination of hydroxypropyl methylcellulose K 15M, sodium carboxy methylcellulose and NaHCO3 can be used to increase the gastric residence time of the dosage form to improve local effect of metronidazole.

Formulation, optimization and evaluation of transferosomal gel for transdermal insulin delivery

The present study deals with the development of transferosomal gel containing insulin by reverse phase evaporation method for painless insulin delivery for use in the treatment of insulin dependent diabetes mellitus. The effect of independent process variables like ratio of lipids (soya lecithin:cholesterol), ratio of lipids and surfactants, and ratio of surfactants (Tween 80:sodium deoxycholate) on the in vitro permeation flux (μg/cm(2)/h) of formulated transferosomal gels containing insulin through porcine ear skin was optimized using 2(3) factorial design. The optimal permeation flux was achieved as 13.50 ± 0.22 μg/cm(2)/h with drug entrapment efficiency of 56.55 ± 0.37% and average vesicle diameter range, 625-815 nm. The in vitro insulin permeation through porcine ear skin from these transferosomal gel followed zero-order kinetics (R (2) = 0.9232-0.9989) over a period of 24 h with case-II transport mechanism. The in vitro skin permeation of insulin from optimized transferosomal gel by iontophoretic influence (with 0.5 mA/cm(2) current supply) also provided further enhancement of permeation flux to 17.60 ± 0.03 μg/cm(2)/h. The in vivo study of optimized transferosomal gel in alloxan-induced diabetic rat has demonstrated prolonged hypoglycemic effect in diabetic rats over 24 h after transdermal administration.

Development, optimization, and anti-diabetic activity of gliclazide-loaded alginate-methyl cellulose mucoadhesive microcapsules

The purpose of this work was to develop and optimize gliclazide-loaded alginate-methyl cellulose mucoadhesive microcapsules by ionotropic gelation using central composite design. The effect of formulation parameters like polymer blend ratio and cross-linker (CaCl(2)) concentration on properties of gliclazide-loaded alginate-methyl cellulose microcapsules like drug encapsulation efficiency and drug release were optimized. The optimized microcapsules were subjected to swelling, mucoadhesive, and in vivo studies. The observed responses coincided well with the predicted values from the optimization technique. The optimized microcapsules showed high drug encapsulation efficiency (83.57 ± 2.59% to 85.52 ± 3.07%) with low T(50%) (time for 50% drug release, 5.68 ± 0.09 to 5.83 ± 0.11 h). The in vitro drug release pattern from optimized microcapsules was found to be controlled-release pattern (zero order) with case II transport release mechanism. Particle sizes of these optimized microcapsules were 0.767 ± 0.085 to 0.937 ± 0.086 mm. These microcapsules also exhibited good mucoadhesive properties. The in vivo studies on alloxan-induced diabetic rats indicated the significant hypoglycemic effect that was observed 12 h after oral administration of optimized mucoadhesive microcapsules. The developed and optimized alginate-methyl cellulose microcapsules are suitable for prolonged systemic absorption of gliclazide to maintain lower blood glucose level and improved patient compliance.

Once daily, high-dose mesalazine controlled-release tablet for colonic delivery: optimization of formulation variables using Box-Behnken design

The aim of this work was to statistically optimize a novel high-dose, mesalazine colonic delivery matrix system, potentially suitable for once daily administration, using simple wet granulation method. A hydrophobic-hydrophilic polymeric blend was used to manipulate drug release. A three-factor, three-level Box-Behnken design was used to construct polynomial models correlating the dependent and independent variables. Independent formulation variables were the percentages of the hydrophilic polymer Carbopol® 940, hydrophobic polymer Eudragit® RS, and the superdisintegrant croscarmellose sodium. The cumulative percentages of drug released at 6, 10, and 14 h were selected as dependent variables and restricted to 7.5-22.5% (Y(1)), 42.5-57.5 % (Y(2)), and 72.5-87.5% (Y(3)), respectively. A second-order polynomial equation fitted to the data was used to optimize the independent formulation variables. Based on Box-Behnken experimental design, different mesalazine release profiles were obtained. The optimized formulation containing 5.72% Carbopol®, 9.77% Eudragit® RS, and 1.45% croscarmellose sodium was prepared according to the software determined levels. It provided a release profile which was very close to the targeted release profile, where the calculated values of f(1) and f(2) were 8.47 and 67.70, respectively, and followed zero-order release kinetics.

Development of cloxacillin loaded multiple-unit alginate-based floating system by emulsion-gelation method

This work investigates the development, optimization and in vitro evaluation of liquid paraffin-entrapped multiple-unit alginate-based floating system containing cloxacillin by emulsion-gelation method for gastro retentive delivery. The effect of process variables like drug to polymer ratio by weight, and liquid paraffin to water ratio by volume on various physicochemical properties in case of liquid paraffin-entrapped calcium alginate beads containing cloxacillin applicable to drug entrapment efficiency, density and drug release was optimized using 3(2) factorial design and analyzed using response surface methodology. The observed (actual values) responses were coincided well with the predicted values, given by the optimization technique. The optimized beads showed drug entrapment efficiency of 64.63±0.78%, density of 0.90±0.05 g/cm(3), and drug release of 56.72±0.85% in simulated gastric fluid (pH 1.2) after 8h with floating lag time of 8.45 min and floated well over 12h in simulated gastric fluid (pH 1.2). The average size of all dried beads ranged from 1.73±0.04 to 1.97±0.08 mm. The beads were characterized by SEM and FTIR for surface morphology and excipients-drug interaction analysis, respectively. All these beads showed prolonged sustained release of cloxacillin over 8h in simulated gastric fluid (pH 1.2). The cloxacillin release profile from liquid paraffin beads followed Korsmeyer-Peppas model over a period of 8h with anomalous (non-Fickian) diffusion mechanism for drug release.

WITHDRAWN: Biosynthesis of silver nanoparticles: Parameter optimization using response surface method

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Preparation and optimization of doxorubicin-loaded albumin nanoparticles using response surface methodology

BACKGROUND

The objective of this work was to optimize the preparation of doxorubicin-loaded albumin nanoparticles (Dox-A-Nps) through desolvation procedures using response surface methodology (RSM). A central composite design (CCD) for four factors at five levels was used in this study.

METHOD

Albumin nanoparticles were prepared through a desolvation method and were optimized in the aid of CCD. Albumin concentration, amount of doxorubicin, pH values, and percentage of glutaraldehyde were selected as independent variables, particle size, zeta potential, drug loading, encapsulation efficiency, and nanoparticles yield were chosen as response variables. RSM and multiple response optimizations utilizing a quadratic polynomial equation were used to obtain an optimal formulation.

RESULTS

The optimal formulation for Dox-A-Nps was composed of albumin concentration of 17 mg/ml, amount of doxorubicin of 2 mg/ml, pH value is 9 and percentage of glutaraldehyde of 125% of the theoretic amount, under which the optimized conditions gave rise to the actual average value of mean particle size (151 ± 0.43 nm), zeta potential (-18.8 ± 0.21 mV), drug loading efficiency (21.4 ± 0.70%), drug entrapment efficiency (76.9 ± 0.21%) and nanoparticles yield (82.0 ± 0.34%). The storage stability experiments proved that Dox-A-Nps stable in 4°C over the period of 4 months. The in vitro experiments showed a burst release at the initial stage and followed by a prolonged release of Dox from albumin nanoparticles up to 60 h.

CONCLUSIONS

This study showed that the RSM-CCD method could efficiently be applied for the modeling of nanoparticles, which laid the foundation of the further research of immuno nanoparticles.

Optimization of the preparation process of vinblastine sulfate (VBLS)-loaded folate-conjugated bovine serum albumin (BSA) nanoparticles for tumor-targeted drug delivery using response surface methodology (RSM)

Response surface methodology (RSM) was used to optimize the process of preparing bovine serum albumin (BSA) nanoparticles by desolvation, then the resulting BSA nanoparticles (BSANPs) were conjugated with folate to produce a drug carrier system that can specifically target tumors. The anticancer drug, vinblastine sulfate (VBLS), was loaded to this tumor-specific drug carrier system for the purpose of overcoming the nonspecific targeting characteristics and side effects of the drug. A central composite design was applied for modeling the process, which was composed of four independent variables, namely BSA concentration, the rate of adding ethanol (ethanol rate), ethanol amount, and the degree of crosslinking. The mean particle size and residual amino groups of the BSANPs were chosen as response variables. The interactive effects of the four independent variables on the response variables were studied. The characteristics of the nanoparticles; such as amount of folate conjugation, drug entrapment efficiency, drug-loading efficiency, surface morphology and release kinetics in vitro were investigated. Optimum conditions for preparing desired BSANPs, with a mean particle size of 156.6 nm and residual amino groups of 668.973 nM/mg, were obtained. The resulting folate-conjugated BSANPs (FA-BSANPs) showed a drug entrapment efficiency of 84.83% and drug-loading efficiency of 42.37%, respectively, and the amount of folate conjugation was 383.996 μM/g BSANPs. The results of this study indicate that using FA-BSANPs as a drug carrier system could be effective in targeting VBLS-sensitive tumors in the future.

Medium optimization for antifungal active substances production from a newly isolated Paenibacillus sp. using response surface methodology

Statistics based experimental designs were used to optimize the medium for antifungal active substances production from a newly isolated Paenibacillus polymyxa Cp-S316 in shaker flask cultivation. The medium components having significant effect on the production were first identified using a fractional factorial design. Then steepest ascent method was employed to approach the experimental design space, followed by an application of response surface methodology for further optimization. A quadratic model was found to fit the antifungal active substances production. Response surface analysis revealed that the optimum values of the tested variables for the production of active substances were 12.3 (g/l) lactose, 17.5 (g/l) peptone, 0.4 (g/l) sodium nitrate, 4.5 (g/l) magnesium sulfate and 100 (g/l) potato. A production of 4687.71microg/ml, which was in agreement with the prediction, was observed in verification experiment. In comparison to the production of basal medium, 3.05-fold increase had been obtained.