Before modern Respiratory Therapy, patients with chronic respiratory ailments were often sent to seaside sanitariums to help with their conditions. It seemed breathing the “salt air” helped.

Inhaled 0.9% saline is a widely used concentration. 0.9% is “isotonic” or often referred as “normal” saline. It is effective as a diluent for drugs or as a moistening agent. 0.9% saline has no osmotic effects to help induce sputum. It is the osmotic effect of hypertonic saline that indicates its use for the induction of sputum where sputum production is indicated help patients with conditions of over-abundant or increased pulmonary mucus by increasing sputum clearance.

In the January 2006 edition of the New England Journal of Medicine published the results the study “A Controlled Trial of Long-Term Inhaled Hypertonic Saline in Patients with Cystic Fibrosis” a collaborative study sponsored by the U.S. Cystic Fibrosis Foundation (http://www.ncbi.nlm.nih.gov/pubmed/16421364)

The study showed that inhaled 7% sterile sodium chloride in 4mls, twice a day was safe and effective in aiding with mucociliary clearance (sputum induction). Further studies showed that effect of mucociliary clearance increases with the concentration of saline (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1758438/pdf/v052p00900.pdf)

Before PharmaCaribe entered the market all hypertonic saline solutions for inhalation were limited to diagnostic use by the indication they were cleared for by FDA. PharmaCaribe filed a new application to broaden the indication for general use wherever induction of sputum production was indicated. This new indication was cleared by PharmaCaribe for commerce in 2010 and in the same year the Cystic Fibrosis Services Pharmacy licensed our 7% concentration exclusively.

Today there are different concentrations available for hypertonic saline starting with 3% and up. The tolerability of hypertonic saline seems to be more of an issue with higher concentrations however the osmotic effect of hypertonic saline seems to increase with the saline concentration (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1758438/pdf/v052p00900.pdf)

In recent years the discussion about the importance of maintaining the physiological pH in the airways emerged (http://link.springer.com/article/10.1007/s00408-004-2511-6).

In Mid 2012 research showed that an acidic modified Airway Surface liquid (ASL) fluid lining of the lung, reduced the subjects own immune response to kill bacteria. (http://www.nature.com/nature/journal/v487/n7405/abs/nature11130.html)

It was found that the average physiologic pH of the lung is 7.4. The National Institute of Health defines the typical physiological pH of the human lung 7.38- 7.42 (average 7.4). However the United States Pharmacopeia (USP) for inhaled saline allows a pH ranging from 4.5 to 7. The average saline pH in products in commerce is 6.2.

PharmaCaribe filed a new 510(k) and made the rational case for approval outside of the USP monograph guidelines for a pH of 7.4, which was cleared for commerce March 2013, PulmoSal (pH+).

At the NACFC 2014 Dr. Jane Burns from the Seattle Children’s Hospital and University of Washington in Seattle, WA USA published a poster called “pH-dependent differential Pseudomonas Aeruginosa Killing in CF Sputum incubated in hypertonic saline solutions” which clearly showed that a hypertonic saline solution with a pH of 7.4 provides a more unfriendly environment for Pseudomonas Aeruginosa colonization compared to other hypertonic saline solutions which are made to USP.