• The subject's assessment of discomfort at the infusion site on a visual analog scale (VAS). [ Time Frame: Before the start of infusion, middle of infusion, end of infusion, and discharge from the clinic ] [ Designated as safety issue: No ]
  

• Safety assessment including adverse events, physical examinations, and vital signs [ Time Frame: Before infusion, during infusion, post infusion, and discharge ] [ Designated as safety issue: Yes ]
  
• Average infusion flow rate (mL/hr) derived from teh time to infuse up to 500mL of solution [ Time Frame: During infusion ] [ Designated as safety issue: No ]
  
• Change in circumference of the thigh at the infusion site [ Time Frame: Before the infusion, during the infusion, after the infusion, and discharge ] [ Designated as safety issue: No ]
  
• Time from the beginning of infusion until the thigh circumference returns to within 5% of baseline circumference. [ Time Frame: Before the infusion until discharge ] [ Designated as safety issue: No ]
  
• Subject's global preference for infusion (left vs. right thigh) [ Time Frame: End of infusion ] [ Designated as safety issue: No ]
  

This Phase IV, randomized, double-blinded study in volunteer subjects to evaluate the tolerability, safety, and flow rates of different solutions subcutaneously (SC) infused and preceded by human recombinant hyaluronidase (hylenex) 150 units. The study will be conducted in two sequential stages.

In Stage 1, the comparison will be NS solution to LR solution. Each subject will receive simultaneous SC infusions of 500 mL (from a 500 mL bag) of solution in each anterior thigh, consisting of NS in one thigh and LR in the other thigh. The thighs (left vs. right) to receive NS and LR will be randomized and double blinded. Immediately prior to the infusions, each thigh will have 150 units of hylenex simultaneously injected.

Tolerability will be assessed based on the subject's self-assessment of discomfort on a visual analog scale (VAS). Safety will be assessed by physical examination targeted at infusion sites, vital signs, and adverse events. The amount of fluid infused will be assessed by weighing the infusion bag, fluid and tubing at designated time points, and allowing the determination of flow rate.

Stage 2 will be conducted only if the observed Stage 1 VAS mean maximum pain score is at least 25 mm higher for one solution compared to the other. Stage 2 will evaluate the tolerability, safety, and flow rates of subcutaneously infused NS solution and buffered NS solution.