Impact of glass corrosion on drug substance stability.

The delamination of glass contact surfaces because of hydrolytic instability has been well documented. However, the lack of glass surface integrity can also lead to other undesirable outcomes prior to visible glass delamination. This work shows how the early stages of delamination, namely, glass corrosion, can influence the chemical stability of active pharmaceutical ingredient (API) solutions contained within a glass container, even prior to the observation of visible delamination. Multiple containers, all constructed of glass classified as USP Type I, were evaluated for hydrolytic stability and how they influence the chemical stability of the API in question. The glass composition of these analytical consumables, the vendor source, and presumably manufacturing process were examined. The implications of glass container durability on product development decisions, the influence on analytical results, and the practice of like-for-like glass container interchangeability are considered.

Teriparatide [rhPTH (1-34)], but not strontium ranelate, demonstrated bone anabolic efficacy in mature, osteopenic, ovariectomized rats.

We compared teriparatide (TPTD) and strontium ranelate (SR) efficacy on bone formation activity in a mature rat model of estrogen-deficiency bone loss. Rats were ovariectomized (OVX) at age 6 months and permitted to lose bone for 2 months to establish osteopenia before initiation of treatment with TPTD (5 or 15 µg/kg · d sc) or SR (150 or 450 mg/kg · d oral gavage). After 3 wk, RT-PCR analyses of bone formation genes in the distal femur metaphysis showed significant elevation of collagen 1α2, osteocalcin, bone sialoprotein, alkaline phosphatase, and Runx2 gene expression at both TPTD doses, relative to OVX controls. SR had no significant effect on expression of these genes. TPTD treatment for 12 wk dose dependently increased lumbar vertebral (LV) and femoral midshaft bone mineral content (BMC) and bone mineral density over pretreatment and age-matched OVX controls. SR 150 increased BMC, and SR 450 increased BMC and bone mineral density of femoral midshaft and LV over OVX controls. There were significant dose-dependent TPTD increases of LV and femoral neck strength, and TPTD 15 also increased midshaft strength compared with pretreatment and age-matched OVX controls. SR did not enhance bone strength relative to pretreatment or age-matched OVX controls. Histomorphometry of the proximal tibial metaphysis showed dose-dependent effects of TPTD on trabecular area, number, width, and osteoblast surface, bone mineralizing surface, and bone formation rate relative to pretreatment and age-matched OVX controls, whereas SR had no effect on these parameters. These findings confirmed the bone anabolic efficacy of teriparatide, but not SR in mature, osteopenic, OVX rats.