Why Eye Drops Must Sterile
Sterilization is critical. Eye solution that made can carry many organisms, the most dangerous is Pseudomonas aeruginosa. eye infections from this organism can cause blindness. This is especially dangerous to use nonsterile products in the eye when the cornea is opened, particulate materials can irritate the eyes, and make patients very discomfort.
Pseudomonas aeruginas (B. pyocyaneus; P. pyocyanea; Blue pas bacillus) is a dangerous and upportunis microorganisms that grow well in culture media that produce toxins and substances / antibacterial products, tend to kill other contaminants and leave the Pseudomonas aeruginosa to grow in pure culture . Gram-negative bacillus becomes a source of serious infection of the cornea. This can cause loss of vision in 24-48 hours. At concentrations that are tolerated by the eye tissues, suggesting that all antimicrobial agents are discussed in the following section may not be effective against some strains of this organism.
Why Eye Drops Must Isotonic
Tonicity means that the osmotic pressure generated by the existence of a solution of dissolved solids or insoluble. Liquid eyes and other body fluids provide the same osmotic pressure with normal saline or 0.9% NaCl solution. Solution that has a larger amount of dissolved material than the eye is called hypertonic fluid. Instead, the fluid has little solute has a lower osmotic pressure are called hypotonic. Eye can tolerate a solution that has a value equivalent tonicity in the range of 0.5% to 1.6% NaCl without great inconvenience.
Tonicity eyewash have more important things than eye drops because of the volume of solution used. With the help of an eyewash and eye patch, eye washed with a solution and then overwhelming the ability of the eye fluid to set some differences in tonicity. If the tonicity eyewash fluid is not approaching the eye, can produce pain and irritation.
In making eye solution, the solution tonicity can be set equal againts lacrimal fluid with the addition of suitable solutes such as NaCl. If the osmotic pressure of the desired drug concentration exceeds the liquid eyes, nothing can be done. Examples 10 and 30% solution of sodium sulfasetamid is hypertonic, the concentration is less than 10% did not give the desired clinical effect. For the hypotonic solution was prepared a number of methods for calculating the amount of NaCl to adjust the tonicity of the eye solution, one method is a method of freezing point depression.
Isotonicity value. Eye fluid isotonic with the blood and have isotonicity values correspond to a solution of Sodium Chloride 0.9% P. Ideally, eye drug solution must have that isotonic value, but the eyes are resistant to isotonic low value which is equivalent to P 2.0% NaCl solution without real nuisance.
Some eye medicines solution need to be hypertonic to increase the absorptive capacity and provide the active ingredient content is high enough to produce the effect of rapid and effective drugs. If the solution of such drugs are used in small quantities, dilution with tears occur rapidly so that the pain caused by hipertonicity only temporary. But, isotonicity adjustment by dilution with tears does not mean, if the hypertonic solution is used in large quantities as koliria to moisten the eyes. So important is the solution of the eye drug for this purpose should be close to isotonic.