Estimation of paracetamol present in a physical mixture containing ketorolac tromethamine solid dispersion with different polymers

Co-administration of combination of paracetamol with non-steroidal anti-inflammatory drugs showed synergistic effects leading to validation of clinical use of this combination in the treatment of majority of pain conditions. Controlled release drug delivery systems based on ketorolac tromethamine solid dispersion with Eudragit RS100, Eudragit RL100, and ethyl cellulose as polymers in a ratio of [1:3] drug:polymer with paracetamol in a physical mixture form were prepared in order to make use of the synergistic effect of this combination. An accurate simple and precise method was developed for simultaneous determination of ketorolac and paracetamol in the proposed solid dispersion preparation; a derivative spectrophotometric method was utilized. The method is based on measuring the first derivative amplitudes [1]D at 338 and 249 for ketorolac and paracetamol in 0.1 N HCl using 0.1 N HCl as a blank with linearity ranges of 2-10 micro g.ml[-1] and mean percent recovery not less than 99% and S.D not more than 0.03. Similarly, the first derivative values of absorbance [1]D at 304nm and 233 nm were measured for ketorolac and paracetamol respectively in phosphate buffer pH 7.4 using phosphate buffer pH 7.4 as a blank with concentration ranges of 2-10 and 3-10 micro g.ml[-1] for ketorolac and paracetamol respectively. The in-vitro drug release studies were performed for both drugs at different pH values. About 25% of ketorolac tromethamine combined with over 90% paracetamol were released at pH 1.2 whereas over 85% of ketorolac and 99% paracetamol were released at pH 7.4 all over the experimental time period. The obtained results can explain the synergistic effect of the proposed combination as well as the decreased gastrotoxic effects of ketorolac

Selection of microencapsulation method to improve antimicrobial agents production by some lactobacillus species and propionibacterium thoenii in dairy products

The aim of this research is to select the agreeable encapsulation method to improve antimicrobial production from Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus rhamnosus and Propionibacterium thoenii. The effect of different organic acid concentrations [1 and 2 w/v], different pH values [3, 4, 5, 6. 7 and 8], different temperature degrees [0, 7, 25, 37 and 45°C] and storage temperature on viability of encapsulated bacteria were investigated. Also, the efficiency of microencapsulated methods [alginate + NaCI, alginate + oil and K-carrageenan] on enhancement of antimicrobial production were studied. Microencapsulation with alginate + NaCI offered greater production in extreme conditions [low pH, low temperature and in the presence of organic acids]. In addition, this method was more effective against pathogenic bacteria by enhancement of antimicrobial production, thus it may be effectively used to increase the safety and the shelf- life of dairy products

Effect of lyophilization on the characteristics and stability of melanin loaded liposomes

The present study was directed to optimize the stability of melanin liposomes utilizing the technique of lyophilization. Two types of cryoprotectants; sucrose and lactose, each in two concentrations of 5% and 10% were used. Lyophilized liposomes [10% lactose] either fresh or stored for one year at 5°C showed no significant changes [P>0.05] in the phase transition temperatures [Tc], structure and shape, and size distribution of the fresh unlyophilized liposomes. The fresh unlyophilized liposomes were unilamellar with Tc of 41.6°C and an average size of 5.21 micro m. The stored unlyophilized liposomes showed a significant [P<0.05] decrease in Tc [32.8°C] and increase in the average size [15.6 micro m] with the formation of onion- like multilamellar vesicles compared with the fresh unlyophilized ones. Lyophilization of melanin liposomes with different cryoprotectants significantly [P<0.001] decreased the rate of leakage of entrapped melanin from the liposomal structure compared with the unlyophilized ones. This cryoprotection effect was significantly [P<0.05] increased by the use of lactose and by increasing the cryoprotectant concentration. The entrapped melanin in lyophilized liposomes with 10% lactose was chemically stable for six months at 5°C as evaluated by mass spectroscopic analysis. As a conclusion, lyophilization with 10% lactose maintained the chemical stability of melanin and significantly improved the physical stability of melanin liposomes