Abstract: Methods and compositions are provided for preparing storage stable partially neutralized acid compositions. The partially neutralized acid compositions are amenable to prolonged periods of storage. Following storage, the acids can be neutralized with a calcium neutralizing source and combined with a lubricant to form a rapidly setting calcium phosphate mineral suitable for a variety of purposes, e.g. bone replacement.

Abstract: Methods, compositions and apparatus are provided for coating a substrate with a strongly adherent hydroxyapatite coating, which allows for ingrowth of natural bone and strong bonding between the coating and the substrate. The procedure provides for coating under conditions which form sticky particles which bind to the substrate to form a crystalline hydroxyapatite coating. The coating has particular application for prostheses, where porous areas of the prostheses are completely coated with a thin sturdy coating of hydroxyapatite.The apparatus includes a coating trough in which the substrates are present and the reactive components added. The medium is recirculated in an outer circuit through a distribution tank solution preparation tank and coating trough. Means are provided for maintaining temperature and pH. The substrates are maintained in a line normal to the flow in the trough and can be rotated to ensure even coating.