# NOVEL HORMONE DELIVERY SYSTEM FOR TREATING OSTEOPENIA

> **NIH NIH R01** · UNIVERSITY OF FLORIDA · 1993 · $176,003

## Abstract

Calcitonin (CT) and parathyroid hormone (PTH) are promising therapeutic
agents for the prevention and reversal of postmenopausal osteoporosis, but
their clinical utility is compromised by high cost and the need for
frequent parenteral administration.  The proposed research involves
testing a novel hormone delivery system in which CT and PTH are
incorporated in biodegradable microspheres, a form allowing weekly rather
than daily injections of the hormones.  The ovariectomized (OVX) rat will
serve as an animal model of estrogen deficiency for comparative studies of
the bone protective effects of daily or alternate day injections of free
hormones and weekly injections of hormone microspheres.

In the first experiment, CT will be evaluated for the prevention of
osteopenia in the estrogen-deficient state.  OVX rats will be treated for
30, 60, or 90 day periods with free CT on alternate days or weekly with CT
microspheres formulated for sustained or pulsatile release.  In the second
experiment, PTH will be evaluated for restoration of lost bone mass in the
estrogen-deficient state.  OVX rats will be untreated for the first month
after surgery to allow for the development of moderate osteopenia.  These
animals will then be treated daily for 30, 60, or 90 day periods with free
PTH or weekly with PTH micro spheres formulated for sustained or pulsatile
release.  In the third experiment, doses and formulations of CT and PTH
microspheres proven to be effective in the first two experiments will be
used for long-term treatments to determine whether the beneficial skeletal
effects of the hormone microspheres can be maintained in aged OVX rats
over an 18 month period.  The skeletal effects of the various treatments
will be studied in cancellous bone tissue of the proximal tibial
metaphysis and lumbar vertebral body as well as cortical bone of the
tibial diaphysis by standard bone histomorphometric techniques.  Changes
in cancellous and cortical bone mass as well as histologic indices of bone
formation, resorption, and mineralization will be measured.  Serum
biochemistry will be performed to determine the effects of CT and PTH
treatment on systemic bone metabolism and serum mineral and hormone
levels.  It is hypothesized that l) weekly injections of CT and PTH
microspheres will be as effective as daily or alternate day injections of
the free hormones for the prevention and reversal of osteopenia in the
estrogen-deplete state, and 2) CT and PTH microspheres formulated for
pulsatile release will be more effective in this regard than hormone
microspheres formulated for sustained release.  Validation of these
hypotheses would provide a rationale for clinical trials of improved
hormone therapies for the prevention and reversal of postmenopausal
osteoporosis.

## Key facts

- **NIH application ID:** 3123384
- **Project number:** 1R01AG011441-01A1
- **Recipient organization:** UNIVERSITY OF FLORIDA
- **SAM.gov UEI:** NNFQH1JAPEP3
- **Principal Investigator:** THOMAS J WRONSKI
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $176,003
- **Award type:** 1
- **Project period:** 1993-09-30 → 1998-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3123384

## Citation

> US National Institutes of Health, RePORTER application 3123384, NOVEL HORMONE DELIVERY SYSTEM FOR TREATING OSTEOPENIA (1R01AG011441-01A1). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3123384. Licensed CC0.

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