The whole problem is that in order for a substitution reaction to occur (whether it be S N 2 or acyl substitution) you need a decent leaving group
Slouka C, Kopp J, Spadiut O, Herwig C
Supporting strategies: Myofascial release techniques
Indications and Usage for B!2 Inject Kit Cyanocobalamin is indicated for vitamin B 12 deficiencies due to malabsorption which may be associated with the following conditions: Addisonian (pernicious) anemia Gastrointestinal pathology, dysfunction, or surgery, including gluten enteropathy or sprue, small bowel bacteria overgrowth, total or partial gastrectomy Fish tapeworm infestation Malignancy of pancreas or bowel Folic acid deficiency It may be possible to treat the underlying disease by surgical correction of anatomic lesions leading to small bowel bacterial overgrowth, expulsion of fish tapeworm, discontinuation of drugs leading to vitamin malabsorption (see Drug Interactions), use of a gluten-free diet in nontropical sprue, or administration of antibiotics in tropical sprue
Freezing is excellent for long-term storage (months), but it's terrible if you need to access the peptide frequently