MANUFACTURING PARAMETERS AND QUALITY CHARACTERISTICS OF SPRAY DRIED JAMEED

Spray drying of jameed - a dried fermented dairy product, is investigated. The study covers the effects of the operating variables upon the physical and chemical characteristics of the dried product. The investigated variables were: feed total solids, feed flow rate, inlet air temperature, air flow rate and atomizer pressure. The product characteristics measured were: total solids, bulk density, average particle size, wettability, dipersibility, color, ash content, salt content, fat content and pH. Best overall results were obtained for a feed total solids of 17%, feed flow rate of 36.5 ml/min, inlet air temperature of 100 /C, air flow rate of 632 cm₃/s, and atomizer pressure of 1.5 bar.     

Thermodynamic behaviour of an air-conditioning system employing combined evaporative-water and air coolers

The performance of an open absorption-system, energized by low-grade heat such as insolation and/or waste heat, has been investigated. This combined evaporative cooler (CEC) [i.e. an indirect evaporative cooler (IEC) together with a direct evaporative-cooler (DEC)] was used to cool the air. A computer simulation of the cooling cycle was devised, so that the performance characteristics of the system could be predicted for a range of operating conditions: the influences of various design-parameters on the coefficient of performance (COP) were also evaluated. The COP of the CEC system was at least 20% greater than those achieved when employing either the IEC or DEC systems alone.     

Transient mixed convection with internal heat generation and oscillating plate temperature

Summary. Oscillating plate temperature effects on transient mixed convection heat transfer from a porous vertical surface with internal heat generation or depletion are considered. The governing equations are transformed into dimensionless form by a set of variables and then solved using the finite element method. It is found that the velocity inside the boundary layer increases and the temperature decreases as time passes. In addition, it is found that when the energy generation is increased, the temperature near the wall will be higher than the wall temperature, and the velocity inside the boundary layer will increase due to an increase of buoyancy forces. Increasing the energy depletion term decreases the velocity inside the boundary layer and increases the heat transfer rate. Different temperature and velocity profiles are drawn for different dimensionless groups. Numerical values of Nusselt number as well as local skin friction coefficient are tabulated. Comparison with previous works shows complete agreement.     

Validation of a simple and rapid HPLC method for determination of metronidazole in dermatological formulations

A rapid and simple method using an isocratic high-pressure liquid chromatography (HPLC) and UV detection for the determination of metronidazole in dermatological formulations is presented. Metronidazole samples were extracted with a solution composed of 60% methanol and 40% mobile phase by a procedure that can be completed in less than 10 min. Subsequent separation and quantification was accomplished in less than 20 min using reversed-phase HPLC with isocratic elution with 0.01% trifluoroacetic acid/acetonitrile (85:15%, vol/vol). Validation experiments confirmed the precision and accuracy of the method. When applied to a commercial metronidazole cream and gel formulation, recoveries of 100.4% for cream formulations and 102.3% for gel formulations were obtained. The method should facilitate studies of the formulation compatibility of metronidazole topical formulations with agents that may improve its clinical tolerability for treatment of rosacea.     

Formulation Compatibility of Myristyl Nicotinate with Drugs Used to Treat Dermatological Conditions Involving an Impaired Skin Barrier

A number of dermatology conditions including skin photodamage, atopic dermatitis, and rosacea involve skin barrier impairment and first line therapies for these conditions including retinoids and steroids further impair skin barrier function. We have evaluated the compatibility of myristyl nicotinate, an agent that enhances skin barrier function, with drugs used to treat conditions where skin barrier impairment is present including photodamage (retinoic acid), atopic dermatitis (hydrocortisone, triamcinolone acetonide), rosacea (metronidazole), and seborrheic dermatitis (ketoconazole). Myristyl nicotinate was found to be compatible with each of the drugs examined when formulated together and also was shown to be photocompatible with retinoic acid. Our results suggest that the combination of myristyl nicotinate with these drugs is a feasible therapeutic development strategy.     

Solar adsorption refrigeration (SAR) system modeling

The solar adsorption refrigeration (SAR) system has economical and environmental aspects that motivate many researches to investigate its capability in cooling system design. In this study, multi-dimensional mathematical models have been generated to predict the coefficient of performance (COP) value of the SAR system as function of the evaporator, condenser, and generator temperatures. Fuzzy logic and regression analysis approaches were implemented to construct a mathematical model for this purpose from one-dimensional collected data that relates COP value separately to condensation, evaporation, and generation temperatures, respectively. The results of COP calculation from the two models were agreed quite well with the measured values. However, the fuzzy logic technique showed excellent accuracy than the regression model when compared to the calculated COP value, as its steps have the optimum nature in constructing the required model.     

Formulation compatibility of myristyl nicotinate with drugs used to treat dermatological conditions involving an impaired skin barrier

A number of dermatology conditions including skin photodamage, atopic dermatitis, and rosacea involve skin barrier impairment and first line therapies for these conditions including retinoids and steroids further impair skin barrier function. We have evaluated the compatibility of myristyl nicotinate, an agent that enhances skin barrier function, with drugs used to treat conditions where skin barrier impairment is present including photodamage (retinoic acid), atopic dermatitis (hydrocortisone, triamcinolone acetonide), rosacea (metronidazole), and seborrheic dermatitis (ketoconazole). Myristyl nicotinate was found to be compatible with each of the drugs examined when formulated together and also was shown to be photocompatible with retinoic acid. Our results suggest that the combination of myristyl nicotinate with these drugs is a feasible therapeutic development strategy.     

Synthesis of Piperazinylalkyl Ester Prodrugs of Ketorolac and their In Vitro Evaluation for Transdermal Delivery

Ketorolac, an NSAID, has low intrinsic permeation capacity through the skin. In this work, seven piperazinylalkyl ester prodrugs of ketorolac were synthesized to enhance its skin permeation. The chemical hydrolysis and the stability in human serum at 37°C were investigated in buffer solutions (pH 5.0 and 7.4) and in 80% human serum (pH 7.4), respectively. The prodrugs were chemically more stable at pH 5.0 than at pH 7.4 with prodrug 8 being the most stable (t_1/2 = 119.75 h and 11.97 h at pH 5 and 7.4, respectively). The prodrugs' t_1/2 in human serum ranged from 0.79 to 3.92 min. The prodrugs' aqueous solubility was measured in buffer solution at pH 5.0 and 7.4 and Log P_app was measured by partitioning between buffer solution (pH 5.0 and 7.4) and n-octanol. The prodrugs were more lipophilic than ketorolac at pH 7.4. Skin permeation of ketorolac and prodrug 8, the most stable chemically, through rat skin was studied at pH 5.0 and 7.4. Prodrug 8 enhanced permeation by 1.56- and 11.39-fold at pH 5 and 7.4, respectively. This is attributed to higher lipophilicity at pH 7.4 and higher aqueous solubility at pH 5 compared to ketorolac.     

MANUFACTURING PARAMETERS AND QUALITY CHARACTERISTICS OF SPRAY DRIED JAMEED

ABSTRACT

Spray drying of jameed - a dried fermented dairy product, is investigated. The study covers the effects of the operating variables upon the physical and chemical characteristics of the dried product. The investigated variables were: feed total solids, feed flow rate, inlet air temperature, air flow rate and atomizer pressure. The product characteristics measured were: total solids, bulk density, average particle size, wettability, dipersibility, color, ash content, salt content, fat content and pH. Best overall results were obtained for a feed total solids of 17%, feed flow rate of 36.5 ml/min, inlet air temperature of 100 /C, air flow rate of 632 cm₃/s, and atomizer pressure of 1.5 bar.