The analgesic efficacy and maternal satisfaction is better with epidural analgesia than with opioids. Analgesia provided by meperidine and tramadol is comparable and approximately 50% of women rated the analgesia as good. Meperidine is better in the second stage than tramadol. Hence in developing nations where availability of facilities is the main limiting factor, intramuscular opioids can be considered suitable alternatives.

Process temperature (30, 40 and 50°C), syrup concentration (50, 60 and 70 o Brix) and process time (4, 5 and 6 h) for osmotic dehydration of papaya (Carica papaya) cubes were optimized for the maximum water loss and optimum sugar gain by using response surface methodology. The peeled and pre-processed papaya cubes of 1 cm size were immersed in sugar syrup at constant temperature water bath having syrup to papaya cubes ratio of 4:1 (w/w). The cubes were removed from bath at predecided time, rinsed with water and weighed. Initial moisture content of papaya samples were 87.5-88.5% (wb), which was reduced to 67.6-81.1% after osmotic dehydration in various experiments showing mass reduction, water loss and sugar gain in the range of 20.6-36.4, 23.2-44.5 and 2.5-8.1%, respectively. The weight reduction, water loss and sugar gain data were statistically analyzed and regression equation of second order were found the best fit for all the experimental data. Maximum water loss of 28% with optimum sugar gain of 4% was predicted for the 60 o Brix syrup concentration at 37°C for syrup to fruit ratio as 4:1 in 4.25 h of osmotic dehydration.

Chitosan is a naturally occurring biopolymer having diversified applications not only in the pharmaceutical field, but also in the biomedical profession. The presence of functional groups, i.e., hydroxyl, acetamido, and amine in the chitosan parent backbone, makes it a suitable candidate for chemical modification, and introduces desired physicochemical and biochemical properties, without any changes in its fundamental skeleton. The various modifications, i.e., alkylation, acylation, quaternization, hydroxyalkylation, carboxyalkylation, thiolation, sulfation, phosphorylation, enzymatic modifications, oligomerization, and graft copolymerization with assorted modifications, and their pharmaceutical and biomedical applications, are discussed in this article. Additionally, it is also limelighted how the chemically engineered chitosan has established a better place with regard to the vista of applications in the arena of sciences such as pharmaceutical, biomedical, biotechnological, tissue engineering, the textile industry, chemistry, the food industry, and many more. This review, hopefully, could enrich knowledge and bring forth new thoughts in line with progress in chitosan polymer science.

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Response surface methodology was used to investigate the effect of brine concentration (10% -20%) solution temperature (35˚C -55˚C), and duration of osmosis (30 -60 min) with respect to water loss (WL) and salt gain (SG). The solution to sample ratio of 5/1 (w/w) was used. The Box-Behnken design of three variables and three levels including seventeen experiments formed by five central points were used for optimizing input parameters. Linear, quadratic and interaction effects of three variables were analyzed with respect to water loss and solid gain. For each response, second order polynomial models were developed using multiple regression analysis. Analysis of variance (ANOVA) was performed to check the adequacy and accuracy of the fitted models. The response surfaces and contour maps showing the interaction of process variables were constructed. The optimum operating conditions were: solution temperature 44.89˚C, brine concentration of 16.53 per cent and duration of osmosis of 47.59 min. At this optimum point, water loss and salt gain were predicted to be 44.55 per cent and 2.98 per cent respectively.

The water desorption properties of osmotically dehydrated papaya cubes at various temperatures were studied by fitting experimental isotherms in Henderson, Oswin, Chen and Clayton and Kuhn equations having 2 parameters and Henderson and Oswin equations were modified to describe the temperature dependence of isotherm data. Oswin equation was useful to predict the equilibrium moisture content values for use in determining the effective moisture diffusion coefficient during subsequent air drying process.