Calcitonin vaginal absorption

Nakada, Y., M. Miyake, and N. Awata. 1993. Some factors affecting the vaginal absorption of human calcitonin in rats. Int J Pharm 89 169. 

Deoxycholate and quillajasaponins were reported to have a positive effect on the vaginal absorption of calcitonin. 

The absorption of drugs from the rectal [32] cavity has been studied in some detail. Muranishi et al. [34] have shown that a significant increase in the absorption and lymphatic uptake of soluble and colloidal macromolecules can be achieved by pretreating the rectal mucosal membrane with lipid-nonionic surfactant mixed micelles. They found no evidence of serious damage of the mucosal membrane. Davis [30] suggested that the vaginal cavity could be an effective delivery site for certain pharmaceuticals, such as calcitonin, used for the treatment of postmenopausal osteoporosis. 

To improve the absorption of peptides and proteins, the employment of different enzymatic inhibitors has been suggested. For example, some authors have demonstrated the usefulness of inhibitors of both exo- and endopeptidases to promote calcitonin absorption across rat vaginal mucosa [93]. A direct relationship was found between the effect of peptidase inhibitors of in vitro degradation constant of calcitonin in vaginal mucosa homogenates and in vivo promotion of drug absorption, indicated by the decrease in plasma calcium levels after calcitonin administration in rats. The peptidase inhibitors tested were pepstatin, bestatin, and leupeptin. 

The vaginal route is considered to be suitable for the local application and absorption of therapeutics like estrogens for hormone replacement therapy or contraception. Systemic absorption of peptide drugs such as LHRH agonists and calcitonin can also be achieved. ... 

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