Structure
Calcitonin is a polypeptide hormone of 32 amino acids, with a molecular weight of 3454.93 daltons. Its structure comprises a single alpha helix. Alternative splicing of the gene coding for calcitonin produces a distantly related peptide of 37 amino acids, called calcitonin gene-related peptide (CGRP), beta type.The following are the amino acid sequences of salmon  and human calcitonin:
salmon:Cys-Ser-Asn-Leu-Ser-Thr-Cys-Val-Leu-Gly-Lys-Leu-Ser-Gln-Glu-Leu-His-Lys-Leu-Gln-Thr-Tyr-Pro-Arg-Thr-Asn-Thr-Gly-Ser-Gly-Thr-Pro

human:Cys-Gly-Asn-Leu-Ser-Thr-Cys-Met-Leu-Gly-Thr-Tyr-Thr-Gln-Asp-Phe-Asn-Lys-Phe-His-Thr-Phe-Pro-Gln-Thr-Ala-Ile-Gly-Val-Gly-Ala-Pro
Compared to salmon calcitonin, human calcitonin differs at 16 residues. Research
In addition to the injectable and nasal spray dosage forms of the salmon calcitonin, noninvasive oral formulations of the peptide are currently under clinical development. The short-half-life of this peptide in serum triggered several attempts to enhance plasma concentrations. The peptide is complexed with a macromolecule that acts as an absorption enhancer through the transcellular pathway and, additionally, protects the peptide from the harsh pH and enzymatic conditions of the GI tract. This complexation is weak, noncovalent and reversible and the drug remains chemically unmodified. After passage through the intestine, the delivery agent dissociates from the peptide. One of the extensively studied oral formulations is the disodium salts of 5-CNAC oral calcitonin. This novel oral platform in a number of clinical trials at different phases has demonstrated promising enhanced pharmacokinetic profile, high bioavailability, well-established safety and comparable efficacy to that of nasal calcitonin especially for treatment of postmenopausal bone loss. See also
Procalcitonin

References
Further reading
External links

The Calcitonin Protein
Calcitonin at the US National Library of Medicine Medical Subject Headings (MeSH)
Naphazoline/pheniramine, sold under the brand name Naphcon-A among others, is a combination eye drop used to help the symptoms of allergic conjunctivitis such as from hay fever. It contains naphazoline and pheniramine. It is used as an eye drop. Use is not recommended for more than three days.Side effects may include allergic reactions, eye pain, and dilated pupils. It is unclear if use in pregnancy is safe. Nephazoline works by resulting in constriction of blood vessels thus decreasing redness while pheniramine works by blocking the effects of histamine to stop itching.The combination was approved for medical use in the United States in 1994. It is available over the counter. In 2017, it was the 203rd most commonly prescribed medication in the United States, with more than two million prescriptions. Medical use
It is administered topically with one to two drops applied to the affected eye(s) up to four times daily. Adverse effects
Pupils may become enlarged temporarily
Overuse may cause more redness
Those with heart disease, high blood pressure, narrow angle glaucoma or who have urination trouble are discouraged from using the product
It is recommended to remove contact lenses before use. Use with contact lenses can lead to reduced oxygenation of the underlying cornea
If infants or children accidentally ingest the drops, it may lead to coma and significant reduction in body temperature. If such ingestion occurs, immediately calling a poison control center is recommended

References
External links
"Naphazoline hydrochloride mixture with pheniramine maleate". Drug Information Portal. U.S. National Library of Medicine.