Lipase-catalyzed Production and Purification of Palm Esters Using Stirred Tank Reactors (STR).

Lipase-catalyzed production of palm esters was performed via alcoholysis of palm oil and oleyl alcohol in solvent and solvent-free systems using a 2 L stirred tank reactor (STR). Two immobilized lipases were tested and Lipozyme RM IM exhibited superior performance in both reaction systems. Reusability studies of the enzymes in a solvent-free system also demonstrated the high stability of Lipozyme RM IM as shown by its ability to yield more than 70% palm esters with up to 19 cycles of reusing the same enzymes. Modification of the enzyme washing process improved the stability of Lipozyme TL IM in a solvent system as demonstrated by maintaining 65% yield after 5 times of repeated enzyme use. The scale up process for both lipases was conducted in the presence of solvents by using the impeller tip speed approach. Lipozyme RM IM-catalyzed reaction in a 15 L STR produced 85.7% yield and there was a significant drop to 60.7% in the 300 L STR, whereas Lipozyme TL IM had a lower yield (65%) when the reaction volume was increased to 15 L. The low yields could be due to the accumulation of enzymes at the bottom of the vessel. Purification of palm esters via solvent-solvent extraction revealed that more than 90% of oleyl alcohol was extracted after the third extraction cycle at 150 rpm impeller speed with reduced palm esters: ethanol ratio (v/v) from 1:4 to 1:3.

Improvement of physicochemical properties of nanocolloidal carrier loaded with low water solubility drug for parenteral cancer treatment by Response Surface Methodology.

Nanoemulsions have been used as a drug carrier system, particularly for poorly water-soluble drugs. Sorafenib is a poorly soluble drug and also there is no parenteral treatment. The aim of this study is the development of nanoemulsions for intravenous administration of Sorafenib. The formulations were prepared by high energy emulsification method and optimized by using Response Surface Methodology (RSM). Here, the effect of independent composition variables of lecithin (1.16-2.84%, w/w), Medium-Chain Triglycerides (2.32-5.68%, w/w) and polysorbate 80 (0.58-1.42%, w/w) amounts on the properties of Sorafenib-loaded nanoemulsion was investigated. The three responses variables were particle size, zeta potential, and polydispersity index. Optimization of the conditions according to the three dependent variables was performed for the preparation of the Sorafenib-loaded nanoemulsions with the minimum value of particle size, suitable rage of zeta potential, and polydispersity index. A formulation containing 0.05% of Sorafenib kept its properties in a satisfactory range over the evaluated period. The composition with 3% Medium-Chain Triglycerides, 2.5% lecithin and 1.22% polysorbate 80 exhibited the smallest particle size and polydispersity index (43.17 nm and 0.22, respectively) with the zeta potential of -38.8 mV was the optimized composition. The fabricated nanoemulsion was characterized by the transmission electron microscope (TEM), viscosity, and stability assessment study. Also, the cytotoxicity result showed that the optimum formulations had no significant effect on a normal cell in a low concentration of the drug but could eliminate the cancer cells. The dose-dependent toxicity made it a suitable candidate for parenteral applications in the treatment of breast cancer. Furthermore, the optimized formulation indicated good storage stability for 3 months at different temperatures (4 ±â€¯2 °C, 25 ±â€¯2 °C and 45 ±â€¯2 °C).

Enhanced physicochemical stability and efficacy of angiotensin I-converting enzyme (ACE) - inhibitory biopeptides by chitosan nanoparticles optimized using Box-Behnken design.

Bromelain-generated biopeptides from stone fish protein exhibit strong inhibitory effect against ACE and can potentially serve as designer food (DF) with blood pressure lowering effect. Contextually, the DF refer to the biopeptides specifically produced to act as ACE-inhibitors other than their primary role in nutrition and can be used in the management of hypertension. However, the biopeptides are unstable under gastrointestinal tract (GIT) digestion and need to be stabilized for effective oral administration. In the present study, the stone fish biopeptides (SBs) were stabilized by their encapsulation in sodium tripolyphosphate (TPP) cross-linked chitosan nanoparticles produced by ionotropic gelation method. The nanoparticles formulation was then optimized via Box-Behnken experimental design to achieve smaller particle size (162.70 nm) and high encapsulation efficiency (75.36%) under the optimum condition of SBs:Chitosan mass ratio (0.35), homogenization speed (8000 rpm) and homogenization time (30 min). The SBs-loaded nanoparticles were characterized for morphology by transmission electron microscopy (TEM), physicochemical stability and efficacy. The nanoparticles were then lyophilized and analyzed using Fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction (XRD). The results obtained indicated a sustained in vitro release and enhanced physicochemical stability of the SBs-loaded nanoparticles with smaller particle size and high encapsulation efficiency following long period of storage. Moreover, the efficacy study revealed improved inhibitory effect of the encapsulated SBs against ACE following simulated GIT digestion.

Optimization of Quercetin loaded Palm Oil Ester Based Nanoemulsion Formulation for Pulmonary Delivery.

In this research, the palm oil ester (POE)- based nanoemulsion formulation containing quercetin for pulmonary delivery was developed. The nanoemulsion formulation was prepared by high energy emulsification method and then further optimized using D-optimal mixture design. The concentration effects of the mixture of POE:ricinoleic acid (RC), ratio 1:1 (1.50-4.50 wt.%), lecithin (1.50-2.50 wt.%), Tween 80 (0.50-1.00 wt.%), glycerol (1.50-3.00 wt.%), and water (88.0-94.9 wt.%) towards the droplet size were investigated. The results showed that the optimum formulation with 1.50 wt.% POE:RC, 1.50 wt.% lecithin, 1.50 wt.% Tween 80, 1.50 wt.% glycerol and 93.90 % water was obtained. The droplet size, polydispersity index (PDI) and zeta potential of the optimized formulation were 110.3 nm, 0.290 and －37.7 mV, respectively. The formulation also exhibited good stability against storage at 4℃ for 90 days. In vitro aerosols delivery evaluation showed that the aerosols output, aerosols rate and median mass aerodynamic diameter of the optimized nanoemulsion were 99.31%, 0.19 g/min and 4.25 µm, respectively. The characterization of physical properties and efficiency for aerosols delivery results suggest that POE- based nanoemulsion containing quercetin has the potential to be used for pulmonary delivery specifically for lung cancer treatment.

Improved collagen extraction from jellyfish (Acromitus hardenbergi) with increased physical-induced solubilization processes.

Efficiency and effectiveness of collagen extraction process contribute to huge impacts to the quality, supply and cost of the collagen produced. Jellyfish is a potential sustainable source of collagen where their applications are not limited by religious constraints and threats of transmittable diseases. The present study compared the extraction yield, physico-chemical properties and toxicology in vitro of collagens obtained by the conventional acid-assisted and pepsin-assisted extraction to an improved physical-aided extraction process. By increasing physical intervention, the production yield increased significantly compared to the conventional extraction processes (p < .05). Collagen extracted using the improved process was found to possess similar proximate and amino acids composition to those extracted using pepsin (p > .05) while retaining high molecular weight distributions and polypeptide profiles similar to those extracted using only acid. Moreover, they exhibited better appearance, instrumental colour and were found to be non-toxic in vitro and free of heavy metal contamination.

Improved In Vivo Efficacy of Anti-Hypertensive Biopeptides Encapsulated in Chitosan Nanoparticles Fabricated by Ionotropic Gelation on Spontaneously Hypertensive Rats.

Recent biotechnological advances in the food industry have led to the enzymatic production of angiotensin I-converting enzyme (ACE)-inhibitory biopeptides with a strong blood pressure lowering effect from different food proteins. However, the safe oral administration of biopeptides is impeded by their enzymatic degradation due to gastrointestinal digestion. Consequently, nanoparticle (NP)-based delivery systems are used to overcome these gastrointestinal barriers to maintain the improved bioavailability and efficacy of the encapsulated biopeptides. In the present study, the ACE-inhibitory biopeptides were generated from stone fish (Actinopyga lecanora) protein using bromelain and stabilized by their encapsulation in chitosan (chit) nanoparticles (NPs). The nanoparticles were characterized for in vitro physicochemical properties and their antihypertensive effect was then evaluated on spontaneously hypertensive rats (SHRs). The results of a physicochemical characterization showed a small particle size of 162.70 nm, a polydispersity index (pdi) value of 0.28, a zeta potential of 48.78 mV, a high encapsulation efficiency of 75.36%, a high melting temperature of 146.78 °C and an in vitro sustained release of the biopeptides. The results of the in vivo efficacy indicated a dose-dependent blood pressure lowering effect of the biopeptide-loaded nanoparticles that was significantly higher (p < 0.05) compared with the un-encapsulated biopeptides. Moreover, the results of a morphological examination using transmission electron microscopy (TEM) demonstrated the nanoparticles as homogenous and spherical. Thus, the ACE-inhibitory biopeptides stabilized by chitosan nanoparticles can effectively reduce blood pressure for an extended period of time in hypertensive individuals.

Enhancement of physicochemical properties of nanocolloidal carrier loaded with cyclosporine for topical treatment of psoriasis: in vitro diffusion and in vivo hydrating action.

Psoriasis is a chronic autoimmune disease that cannot be cured. It can however be controlled by various forms of treatment, including topical, systemic agents, and phototherapy. Topical treatment is the first-line treatment and favored by most physicians, as this form of therapy has more patient compliance. Introducing a nanoemulsion for transporting cyclosporine as an anti-inflammatory drug to an itchy site of skin disease would enhance the effectiveness of topical treatment for psoriasis. The addition of nutmeg and virgin coconut-oil mixture, with their unique properties, could improve cyclosporine loading and solubility. A high-shear homogenizer was used in formulating a cyclosporine-loaded nanoemulsion. A D-optimal mixture experimental design was used in the optimization of nanoemulsion compositions, in order to understand the relationships behind the effect of independent variables (oil, surfactant, xanthan gum, and water content) on physicochemical response (particle size and polydispersity index) and rheological response (viscosity and k-value). Investigation of these variables suggests two optimized formulations with specific oil (15% and 20%), surfactant (15%), xanthan gum (0.75%), and water content (67.55% and 62.55%), which possessed intended responses and good stability against separation over 3 months' storage at different temperatures. Optimized nanoemulsions of pH 4.5 were further studied with all types of stability analysis: physical stability, coalescence-rate analysis, Ostwald ripening, and freeze-thaw cycles. In vitro release proved the efficacy of nanosize emulsions in carrying cyclosporine across rat skin and a synthetic membrane that best fit the Korsmeyer-Peppas kinetic model. In vivo skin analysis towards healthy volunteers showed a significant improvement in the stratum corneum in skin hydration.

Physicochemical Properties of Jatropha Oil-Based Polyol Produced by a Two Steps Method.

A low cost, abundant, and renewable vegetable oil source has been gaining increasing attention due to its potential to be chemically modified to polyol and thence to become an alternative replacement for the petroleum-based polyol in polyurethane production. In this study, jatropha oil-based polyol (JOL) was synthesised from non-edible jatropha oil by a two steps process, namely epoxidation and oxirane ring opening. In the first step, the effect of the reaction temperature, the molar ratio of the oil double bond to formic acid, and the reaction time on the oxirane oxygen content (OOC) of the epoxidised jatropha oil (EJO) were investigated. It was found that 4.3% OOC could be achieved with a molar ratio of 1:0.6, a reaction temperature of 60 °C, and 4 h of reaction. Consequently, a series of polyols with hydroxyl numbers in the range of 138-217 mgKOH/g were produced by oxirane ring opening of EJOs, and the physicochemical and rheological properties were studied. Both the EJOs and the JOLs are liquid and have a number average molecular weight (Mn) in the range of 834 to 1457 g/mol and 1349 to 2129 g/mol, respectively. The JOLs exhibited Newtonian behaviour, with a low viscosity of 430-970 mPas. Finally, the JOL with a hydroxyl number of 161 mgKOH/g was further used to synthesise aqueous polyurethane dispersion, and the urethane formation was successfully monitored by Fourier Transform Infrared (FTIR).

An Artificial Neural Network Based Analysis of Factors Controlling Particle Size in a Virgin Coconut Oil-Based Nanoemulsion System Containing Copper Peptide.

A predictive model of a virgin coconut oil (VCO) nanoemulsion system for the topical delivery of copper peptide (an anti-aging compound) was developed using an artificial neural network (ANN) to investigate the factors that influence particle size. Four independent variables including the amount of VCO, Tween 80: Pluronic F68 (T80:PF68), xanthan gum and water were the inputs whereas particle size was taken as the response for the trained network. Genetic algorithms (GA) were used to model the data which were divided into training sets, testing sets and validation sets. The model obtained indicated the high quality performance of the neural network and its capability to identify the critical composition factors for the VCO nanoemulsion. The main factor controlling the particle size was found out to be xanthan gum (28.56%) followed by T80:PF68 (26.9%), VCO (22.8%) and water (21.74%). The formulation containing copper peptide was then successfully prepared using optimum conditions and particle sizes of 120.7 nm were obtained. The final formulation exhibited a zeta potential lower than -25 mV and showed good physical stability towards centrifugation test, freeze-thaw cycle test and storage at temperature 25°C and 45°C.

Nutritional composition and total collagen content of three commercially important edible jellyfish.

The study aimed to evaluate nutraceutical potential of three commercially significant edible jellyfish species (Acromitus hardenbergi, Rhopilema hispidum and Rhopilema esculentum). The bell and oral arms of these jellyfishes were analyzed for their proximate composition, calorific value, collagen content, amino acid profile, chemical score and elemental constituent. In general, all jellyfish possessed low calorific values (1.0-4.9 kcal/g D.W.) and negligible fat contents (0.4-1.8 g/100 g D.W.), while protein (20.0-53.9 g/100 g D.W.) and minerals (15.9-57.2g/100g D.W.) were found to be the richest components. Total collagen content of edible jellyfish varied from 122.64 to 693.92 mg/g D.W., accounting for approximately half its total protein content. The dominant amino acids in both bell and oral arms of all jellyfish studied includes glycine, glutamate, threonine, proline, aspartate and arginine, while the major elements were sodium, potassium, chlorine, magnesium, sulfur, zinc and silicon. Among the jellyfish, A. hardenbergi exhibited significantly higher total amino acids, chemical scores and collagen content (p<0.05) compared to R. hispidum and R. esculentum. Having good protein quality and low calories, edible jellyfish is an appealing source of nutritive ingredients for the development of oral formulations, nutricosmetics and functional food.

Ultrasonic emulsification of parenteral valproic acid-loaded nanoemulsion with response surface methodology and evaluation of its stability.

Response surface methodology (RSM) was used to optimize the formulation of a nanoemulsion for central delivery following parenteral administration. A mixture of medium-chain triglyceride (MCT) and safflower seed oil (SSO) was determined as a sole phase from the emulsification properties. Similarly, a natural surfactant (lecithin) and non-ionic surfactant (Tween 80) (ratio 1:2) were used in the formulation. A central composite design (CCD) with three-factor at five-levels was used to optimize the processing method of high energy ultrasonicator. Effects of pre-sonication ultrasonic intensity (A), sonication time (B), and temperature (C) were studied on the preparation of nanoemulsion loaded with valproic acid. Influence of the aforementioned specifically the effects of the ultrasonic processing parameters on droplet size and polydispersity index were investigated. From the analysis, it was found that the interaction between ultrasonic intensity and sonication time was the most influential factor on the droplet size of nanoemulsion formulated. Ultrasonic intensity (A) significantly affects the polydispersity index value. With this optimization method, a favorable droplet size of a nanoemulsion with reasonable polydispersity index was able to be formulated within a short sonication time. A valproic acid loaded nanoemulsion can be obtained with 60% power intensity for 15 min at 60 °C. Droplet size of 43.21±0.11 nm with polydispersity index of 0.211 were produced. The drug content was then increased to 1.5%. Stability study of nanoemulsion containing 1.5% of valproic acid had a good stability as there are no significant changes in physicochemical aspects such as droplet size and polydispersity index. With the characteristisation study of pH, viscosity, transmission electron microscope (TEM) and stability assessment study the formulated nanoemulsion has the potential to penetrate blood-brain barrier in the treatment of epilepsy.

Physicochemical characterization and thermodynamic studies of nanoemulsion-based transdermal delivery system for fullerene.

Fullerene nanoemulsions were formulated in palm kernel oil esters stabilized by low amount of mixed nonionic surfactants. Pseudoternary phase diagrams were established in the colloidal system of PKOEs/Tween 80 : Span 80/water incorporated with fullerene as antioxidant. Preformulation was subjected to combination of high and low energy emulsification methods and the physicochemical characteristics of fullerene nanoemulsions were analyzed using electroacoustic spectrometer. Oil-in-water (O/W) nanoemulsions with particle sizes in the range of 70-160 nm were formed. The rheological characteristics of colloidal systems exhibited shear thinning behavior which fitted well into the power law model. The effect of xanthan gum (0.2-1.0%, w/w) and beeswax (1-3%, w/w) in the estimation of thermodynamics was further studied. From the energetic parameters calculated for the viscous flow, a moderate energy barrier for transport process was observed. Thermodynamic study showed that the enthalpy was positive in all xanthan gum and beeswax concentrations indicating that the formation of nanoemulsions could be endothermic in nature. Fullerene nanoemulsions with 0.6% or higher xanthan gum content were found to be stable against creaming and flocculation when exposed to extreme environmental conditions.

Formulation development and optimization of palm kernel oil esters-based nanoemulsions containing sodium diclofenac.

Response surface methodology was employed to study the effect of formulation composition variables, water content (60%-80%, w/w) and oil and surfactant (O/S) ratio (0.17-1.33), as well as high-shear emulsification conditions, mixing rate (300-3,000 rpm) and mixing time (5-30 minutes) on the properties of sodium diclofenac-loaded palm kernel oil esters-nanoemulsions. The two response variables were droplet size and viscosity. Optimization of the conditions according to the four variables was performed for preparation of the nanoemulsions with the minimum values of particle size and viscosity. The results showed that the experimental data could be sufficiently fitted into a third-order polynomial model with multiple regression coefficients (R(2) ) of 0.938 and 0.994 for the particle size and viscosity, respectively. Water content, O/S ratio and mixing time, quadrics of all independent variables, interaction between O/S ratio and mixing rate and between mixing time and rate, as well as cubic term of water content had a significant effect (P<0.05) on the particle size of nanoemulsions. The linear effect of all independent variables, quadrics of water content and O/S ratio, interaction of water content and O/S ratio, as well as cubic term of water content and O/S ratio had significant effects (P<0.05) on the viscosity of all nanoemulsions. The optimum conditions for preparation of sodium diclofenac nanoemulsions were predicted to be: 71.36% water content; 0.69 O/S ratio; 950 rpm mixing rate, and 5 minute mixing time. The optimized formulation showed good storage stability in different temperatures.

Characterization of structural stability of palm oil esters-based nanocosmeceuticals loaded with tocotrienol.

BACKGROUND: Palm oil esters (POEs) are esters derived from palm oil and oleyl alcohol have great potential in the cosmetic and pharmaceutical industries due to the excellent wetting behavior of the esters without the oily feel. The role of oil-in-water nanoemulsions loaded with tocotrienol sedimentation behavior was studied. LUMiFuge® 116 particle separation analyzer was used to investigate the sedimentation behavior of POEs/tocotrienol/xanthan gum nanoemulsion system during centrifugation. Analyzing the sedimentation kinetics of dispersions in a centrifugal field also yields information about the rheological behavior and structural stability. METHODS: Experiments were performed in an analytical centrifuge at 11 × g to 1140 × g (LUMiFuge® 116 particle separation analyzer). The samples in the LUMiFuge® 116 particle separation analyzer were centrifuged at 3000 rpm for 15 h at 32°C. Sample volume of 2 cm3 was used. The rheological property of nanoemulsions was investigated using oscillatory measurements test. A rotational/oscillatory viscometer, Kinexus Rheometer (Malvern Instrument, UK) was used. All measurements were performed with a stainless steel cone-plate sensor at 25.0 ± 0.1°C with 4°/40 mm. RESULTS: The stable nanoemulsions showed sedimentation rates at earth gravity of 5.2, 3.0 and 2.6 mm/month for 10%, 20% and 30% (w/w) oil phase, respectively. Rheological behavior is an important target during the design of palm oil esters-based nanocosmeceuticals. The presence of a network structure was indicated by measurements which showed G' to be greater than G". This result implied the predominant elastic response and high storage stability of the nanoemulsion. It was also observed that the increase in oil phase concentration led to the profile which strongly indicated that the solid like elastic property; where the values of phase angle, δ of these nanoemulsions was lower than 45°. CONCLUSIONS: The nanoemulsions with higher oil phase concentration (30% (w/w)) showed greater elasticity which implied strong dynamic rigidity of the nanoemulsion. It was the most stable with longest shelf-life.

Formulation optimization of palm kernel oil esters nanoemulsion-loaded with chloramphenicol suitable for meningitis treatment.

Palm kernel oil esters nanoemulsion-loaded with chloramphenicol was optimized using response surface methodology (RSM), a multivariate statistical technique. Effect of independent variables (oil amount, lecithin amount and glycerol amount) toward response variables (particle size, polydispersity index, zeta potential and osmolality) were studied using central composite design (CCD). RSM analysis showed that the experimental data could be fitted into a second-order polynomial model. Chloramphenicol-loaded nanoemulsion was formulated by using high pressure homogenizer. The optimized chloramphenicol-loaded nanoemulsion response values for particle size, PDI, zeta potential and osmolality were 95.33nm, 0.238, -36.91mV, and 200mOsm/kg, respectively. The actual values of the formulated nanoemulsion were in good agreement with the predicted values obtained from RSM. The results showed that the optimized compositions have the potential to be used as a parenteral emulsion to cross blood-brain barrier (BBB) for meningitis treatment.

Carbopol 934, 940 and Ultrez 10 as viscosity modifiers of palm olein esters based nano-scaled emulsion containing ibuprofen.

Micro-emulsions and sometimes nano-emulsions are well known candidates to deliver drugs locally. However, the poor rheological properties are marginally affecting their acceptance pharmaceutically. This work aimed to modify the poor flow properties of a nano-scaled emulsion comprising palm olein esters as the oil phase and ibuprofen as the active ingredient for topical delivery. Three Carbopol ® resins: 934, 940 and Ultrez 10, were utilized in various concentrations to achieve these goals. Moreover, phosphate buffer and triethanolamine solutions pH 7.4 were used as neutralizing agents to assess their effects on the gel-forming and swelling properties of Carbopol ® 940. The addition of these polymers caused the produced nano-scaled emulsion to show a dramatic droplets enlargement of the dispersed globules, increased intrinsic viscosity, consistent zeta potential and transparent-to-opaque change in appearance. These changes were relatively influenced by the type and the concentration of the resin used. Carbopol ® 940 and triethanolamine appeared to be superior in achieving the proposed tasks compared to other materials. The higher the pH of triethanolamine solution, the stronger the flow-modifying properties of Carbopol ® 940. Transmission electron microscopy confirmed the formation of a well-arranged gel network of Carbopol ® 940, which was the major cause for all realized changes. Later in vitro permeation studies showed a significant decrease in the drug penetration, thus further modification using 10% w/w menthol or limonene as permeation promoters was performed. This resulted in in vitro and in vivo pharmacodynamics properties that are comparably higher than the reference chosen for this study.

Formulation optimization of a palm-based nanoemulsion system containing levodopa.

Response surface methodology (RSM) was utilized to investigate the influence of the main emulsion composition; mixture of palm and medium-chain triglyceride (MCT) oil (6%-12% w/w), lecithin (1%-3% w/w), and Cremophor EL (0.5%-1.5% w/w) as well as the preparation method; addition rate (2-20 mL/min), on the physicochemical properties of palm-based nanoemulsions. The response variables were the three main emulsion properties; particle size, zeta potential and polydispersity index. Optimization of the four independent variables was carried out to obtain an optimum level palm-based nanoemulsion with desirable characteristics. The response surface analysis showed that the variation in the three responses could be depicted as a quadratic function of the main composition of the emulsion and the preparation method. The experimental data could be fitted sufficiently well into a second-order polynomial model. The optimized formulation was stable for six months at 4 °C.

Modification of palm kernel oil esters nanoemulsions with hydrocolloid gum for enhanced topical delivery of ibuprofen.

INTRODUCTION: During recent years, there has been growing interest in the use of nanoemulsion as a drug-carrier system for topical delivery. A nanoemulsion is a transparent mixture of oil, surfactant and water with a very low viscosity, usually the product of its high water content. The present study investigated the modification of nanoemulsions with different hydrocolloid gums, to enhanced drug delivery of ibuprofen. The in vitro characterization of the initial and modified nanoemulsions was also studied. METHODS: A palm kernel oil esters nanoemulsion was modified with different hydrocolloid gums for the topical delivery of ibuprofen. Three different hydrocolloids (gellan gum, xanthan gum, and carrageenan) were selected for use. Ternary phase diagrams were constructed using palm kernel oil esters as the oil, Tween 80 as the surfactant, and water. Nanoemulsions were prepared by phase inversion composition, and were gradually mixed with the freshly prepared hydrocolloids. The initial nanoemulsion and modified nanoemulsions were characterized. The abilities of the nanoemulsions to deliver ibuprofen were assessed in vitro, using a Franz diffusion cell fitted with rat skin. RESULTS: No significant changes were observed in droplet size (~16-20 nm) but a significant difference in polydispersity indexes were observed before and after the modification of nanoemulsions using gellan gum, carrageenan, and xanthan gum. The zeta potentials of the initial nanoemulsions (-11.0 mV) increased to -19.6 mV, -13.9 mV, and -41.9 mV, respectively. The abilities of both the initial nanoemulsion (T802) and the modified nanoemulsion to deliver ibuprofen through the skin were evaluated in vitro, using Franz diffusion cells fitted with rat skin. The in vitro permeation data showed that the modified nanoemulsion (Kp value of 55.4 × 10(-3) cm · h(-1)) increased the permeability of ibuprofen 4.40 times over T802 (Kp value of 12.6 × 10(-3) cm · h(-1)) (P < 0.05). CONCLUSION: The modified nanoemulsion may be a promising vehicle to enhance the permeation of ibuprofen for topical delivery.

Manipulation of the conformation and enzymatic properties of T1 lipase by site-directed mutagenesis of the protein core.

In silico and experimental investigations were conducted to explore the effects of substituting hydrophobic residues, Val, Met, Leu, Ile, Trp, and Phe into Gln 114 of T1 lipase. The in silico investigations accurately predicted the enzymatic characteristics of the mutants in the experimental studies and provided rationalization for some of the experimental observations. Substitution with Leu successfully improved the conformational stability and enzymatic characteristics of T1 lipase. However, replacement of Gln114 with Trp negatively affected T1 lipase and resulted in the largest disruption of protein stability, diminished lipase activity and inferior enzymatic characteristics. These results suggested that the substitution of a larger residue in a densely packed area of the protein core can have considerable effects on the structure and function of an enzyme. This is especially true when the residue is next to the catalytic serine as demonstrated with the Phe and Trp mutation.

Study of surface activity of piroxicam at the interface of palm oil esters and various aqueous phases.

The surface activity of some non-steroidal anti-inflammatory agents like ibuprofen was investigated extensively. This fact has attracted the researchers to extend this behavior to other agents like piroxicam. Piroxicam molecules are expected to orient at the interface of oil and aqueous phase. The aim of this study was, firstly, to assess the surface and interfacial tension behaviour of newly synthesised palm oil esters and various pH phosphate buffers. Furthermore, the surface and interfacial tension activity of piroxicam was studied. All the measurements of surface and interfacial tension were made using the tensiometer. The study revealed that piroxicam has no effect on surface tension values of all pH phosphate buffers and palm oil esters. Similarly, various concentrations of piroxicam did not affect the interfacial tensions between the oil phase and the buffer phases. Accordingly, the interfacial tension values of all mixtures of oil and phosphate buffers were considerably high which indicates the immiscibility. It could be concluded that piroxicam has no surface activity. Additionally, there is no surface pressure activity of piroxicam at the interface of plam oil esters and phosphate buffers in the presence of Tweens and Spans.