Controlled-Release Vitamin D Therapy for Secondary Hyperparathyroidism
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Solution Overview
Problem
Current Vitamin D supplements for treating secondary hyperparathyroidism in CKD patients are ineffective due to rapid surges in blood Vitamin D levels, leading to decreased systemic bioavailability, aberrations in calcium and phosphorus homeostasis, and over suppression of PTH secretion, which are not adequately addressed by existing therapies.
Innovation Solution
Administering both Vitamin D repletion and Vitamin D hormone replacement therapies in controlled release formulations to maintain blood concentrations of 25-hydroxyvitamin D above 30 ng/mL and 1,25-dihydroxyvitamin D within normal physiological ranges, using predominantly 25-hydroxyvitamin D3 to prevent hypercalcemia and hyperphosphatemia, and manage plasma iPTH levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If Vitamin D supplements are administered to treat secondary hyperparathyroidism, then blood Vitamin D levels increase, but rapid surges occur leading to decreased systemic bioavailability and aberrations in calcium and phosphorus homeostasis
Solution Approach 1:
The patent employs periodic, controlled-release administration of Vitamin D compounds to deliver sustained low-dose therapy rather than single high-dose bolus administration. This periodic action maintains stable blood concentrations over time, preventing the rapid surges that cause decreased bioavailability and metabolic aberrations.
Solution Approach 2:
The invention uses dynamic controlled-release formulations that adjust the release rate of Vitamin D to maintain optimal blood concentrations. This dynamic approach allows the therapy to adapt to the patient's metabolic needs, ensuring reliable systemic bioavailability while avoiding toxic accumulation.
2Quantity of substance
If high doses of Vitamin D are administered to raise blood levels, then 25-hydroxyvitamin D concentrations increase, but this causes over suppression of PTH secretion and hypercalcemia
Solution Approach 1:
The patent changes the dosing parameters from high single doses to lower frequent doses, and modifies the release kinetics parameter of Vitamin D administration. This parameter optimization achieves the desired 25-hydroxyvitamin D concentration threshold (>30 ng/mL) while maintaining PTH suppression within therapeutic ranges and preventing hypercalcemia.
Solution Approach 2:
The controlled-release formulations incorporate feedback mechanisms where the release rate of Vitamin D is regulated based on maintaining target blood concentration ranges. This feedback control prevents both under-dosing (ineffective PTH suppression) and over-dosing (hypercalcemia and excessive PTH suppression).
3Quantity of substance
If conventional Vitamin D therapy is used, then PTH levels may be suppressed, but calcium and phosphorus homeostasis becomes aberrant
Solution Approach 1:
The sustained periodic administration of controlled-release Vitamin D formulations maintains stable blood concentrations that reliably suppress PTH while simultaneously maintaining normal calcium and phosphorus homeostasis. The periodic low-dose delivery prevents the metabolic disruptions caused by intermittent high-dose therapy.
Data Source
AI summary
The method of treating elevated blood levels of iPTH by increasing or maintaining blood concentrations of both 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D in a patient by administering, as necessary, both Vitamin D repletion and Vitamin D hormone replacement therapies, is disclosed. The blood concentrations of 25-hydroxyvitamin D are increased to and maintained at or above 30 ng/mL, and blood concentrations of 1,25-dihydroxyvitamin D are increased to or maintained within a patient's normal historical physiological range for 1,25-dihydroxyvitamin D without causing substantially increased risk of hypercalcemia, hyperphosphatemia or over suppression of plasma iPTH in the patient. The blood levels of 25-hydroxyvitamin D are maintained at or above 30 ng/mL between doses of Vitamin D repletion therapies, and the blood levels of 1,25-dihydroxyvitamin D are maintained in the patient's normal historical physiological range between doses of Vitamin D hormone replacement therapies. In one aspect, the disclosure includes methods wherein the blood concentration of 25-hydroxyvitamin D during treatment comprises predominantly 25-hydroxyvitamin D3, and/or wherein the method includes administering predominantly or solely 25-hydroxyvitamin D3 for 25-hydroxyvitamin D repletion and/or maintenance.