Formulation and in vitro evaluation of sustained release matrix tablets using cross-linked natural gum

Polysaccharide gums because of their biocompatibility, biodegradability and non-immunogenic properties are considered as the best choice for preparing sustained release tablets as compared to their synthetic counterpart. The cross linking of natural gums in matrix tablets increase the sustained release property of matrix tablets. Isoniazid is a first line therapy of tuberculosis, belongs to BCS I with half-life of 3-4 hours. These characteristics make isoniazid a good candidate for sustained release dosage form. Karaya gum crossed linked with trisodium tri metaphosphate was used as release rate retardant for preparing isoniazid cross-linked matrix tablet. Total 8 sustained release formulations were prepared. Both granules and tablets were evaluated under in vitro condition against different parameters. Dissolution studies were performed with all eight formulations for 12 hours using USP apparatus I. Four formulations designated as F1, F2, F3, F4 have drug and karaya gum while other four formulations F5, F6, F7, F8 have drug and crossed linked polymer in ratios of 1:1, 1:2, 1:3 and 1:4 respectively. Dissolution data was analyzed by using different kinetic models. Best fit model for most efficient formulation was zero order while release mechanism was super case I. Formulation 8 showed sufficiently slow release kinetics and about 83% of drug was released in 10 hours, indicating that cross-linked karaya gum proved efficient in preparing sustained release tablets

Preparation and in vitro evaluation of Nystatin micro emulsion based gel

Nystatin is a polyene antimycotic obtained from Streptomyces noursei used in the treatment of topical and transdermal fungal infection. Nystatin is nearly insoluble in water [<0.1] and it is amphoteric in nature. The aim of the present study was to design and develop Nystatin micro emulsion based gel for efficient delivery of drug to the skin by water titration method. The Pseudoternary phase diagrams 1:2, 1:1 and 2:1 were constructed by water titration method. Micro emulsion based gel was prepared by using oleic acid, Tween 20, propylene glycol as an oil phase, surfactant and cosurfactant respectively. Cabopol 940 was used as a gelling agent. In vitro evaluation of micro emulsion based gel was done for pH, Viscosity, spreadability and droplet size. Micro emulsion based gel showed greater antifungal activity against Candida albicansas compared to control formulations. In vitro drug release studies were conducted for micro emulsion based gel and control formulation using Franz diffusion cell. Drug penetration through synthetic skin followed Zero order model as the values for R[2] higher in case of zero order equation. The optimized micro emulsion based gel was found to be stable and showed no physical changes when exposed to different temperatures for a period of 4 week. The results indicated that the micro emulsion based gel system studied would be a promising tool for enhancing the percutaneous delivery of Nystatin

Herpes Simplex Virus-2 infection amongst urban male population in Pakistan

To describe the prevalence of Herpes Simplex Virus-2 [HSV-2] infection among males in six major cities of Pakistan. A cross sectional behavioural and biological survey of urban male population aged 16-45 years was conducted in Rawalpindi, Lahore, Karachi, Faisalabad, Peshawar and Quetta to measure the prevalence of five sexually transmitted infections and assess sexual behaviours. Respondents were selected through a multistage sampling technique. In each city 10 blocks demarcated by the Population Census Organization were selected based on probability proportional to socio-economic status. In each block 40 men were selected through systematic sampling with a random start. In total 2400 men were administered a behavioural questionnaire and 2396 provided biological specimens for laboratory testing. This paper discusses the overall and city wise prevalence of HSV-2 infection. The overall prevalence of HSV-2 infection in the six cities was 3.4 percent [95% Cl 2.8-4.3]. City wise the highest prevalence was reported in Karachi 6 percent [95% Cl 4.1-8.8], followed by Lahore and Quetta at 4.3 percent [95% Cl 2.7-6.7], and Faisalabad at 2.5 percent [95% Cl 1.4-4.5]. The lowest prevalence was in Rawalpindi at 1.8 percent [95% Cl 0.9-3.6]. Empirical evidence from this study suggests that there is city wise variation in the prevalence of HSV-2 infection across the major cities in Pakistan. Based on possible link between HSV-2 and HIV, future HIV control strategies must also focus on the better management of HSV-2 infections in Pakistan

Formulation and in vitro evaluation of a cosmetic emulsion from almond oil

Several processes are used for the manufacture of multiple emulsions. The most widely used procedure is two step method. 1st step consists of preparing a primary emulsion. In the 2nd step, a definite amount of this primary emulsion is dispersed in an external phase containing the secondary emulsifier. Although it is a simple method, the 2nd step of the procedure includes many critical factors. In this work water-in-oil-in-water w/o/w multiple emulsion was prepared by using almond oil, Abil-EM 90, magnesium sulfate, Tween 80. The multiple emulsion was prepared by using two-step process. Stability studies of this multiple emulsion were carried out at different storage conditions i.e. 8°C, 25°C, 40°C and 40°C+ 75% relative humidity [RH] for 28 days. It was found that samples of multiple emulsion stored at 8°C, 25°C were stable through out the study period but samples stored at 40°C and 40°C+ 75% RH were found to show some changes in color, liquefaction and phase separation from third week. The changes in pH values and electrical conductivity of multiple emulsions stored at these storage conditions were also measured. Globules sizes of multiple emulsion were also measured at these storage conditions. Results indicate that there were significant changes in pH values and electrical conductivity of multiple emulsion stored at different conditions and non significant changes in globule sizes of multiple emulsion stored at these conditions were observed