. 2013 Apr 1;3(2):e25103. doi: 10.4161/biom.25103

Table 2. Classification of the methods used to produce spherical CaP particles according to the types of reagents, the dispersion media, the dispersion tools, the consolidation methods, the resulting diameters, and the final compositions.

Reagents	Dispersion media	Dispersion tool	Consolidation	Method name	Diameter	Composition
Solution	No dispersion	-	Precipitation	Precipitation⁴⁷^-⁵⁰^,⁵⁶^,¹⁰²^,¹⁰³^,¹¹⁰^-¹¹⁵^,¹¹⁸^,¹²⁵^,¹²⁷^,¹²⁹^,¹³¹^,¹⁵⁶^-¹⁶¹	0.01–1000 μm	DCPD ⁵⁰
						OCP ¹⁰² ^, ¹²⁹ ^, ¹³¹ ^, ¹⁵⁶ ^, ¹⁵⁹
						ACP ⁴⁷ ^, ⁴⁹ ^, ¹⁰³ ^, ¹¹² ^- ¹¹⁴ ^, ¹²⁵
						β-TCP ⁵⁶
						HA ⁴⁷ ^, ⁴⁸ ^, ¹⁰² ^, ¹¹⁰ ^- ¹¹⁵ ^, ¹²⁵ ^, ¹²⁷ ^, ¹⁵⁶ ^- ¹⁵⁸ ^, ¹⁶⁰ ^, ¹⁶¹
	Gas (Aerosol)	Nozzle (high energy)	Pyrolysing and drying	Flame-synthesis⁵⁷^-⁶⁰^,¹⁶²^-¹⁶⁵ ( = spray pyrolysis)	0.01–6 μm	MCPM ⁵⁹
						DCP ⁵⁹
						ACP ⁵⁹ ^, ¹⁶²
						β-TCP ⁵⁷
						HA ⁵⁷ ^- ⁶⁰ ^, ¹⁶³ ^- ¹⁶⁵
		Nozzle (high energy)	Drying	Spray-drying⁵²	0.1–5 μm	HA ⁵²
				Electrospraying¹⁶⁶	1–7 µm	β-TCP ¹⁶⁶
	Liquid (Emulsion)	Propeller	Precipitation	Precipitation-emulsification⁵⁰^,⁵¹^,⁶¹^,¹⁴⁸	0.02–20 μm	DCPD ⁵⁰
						ACP ⁵¹ ^, ⁶¹
						HA ⁵¹ ^, ⁶¹ ^, ¹⁴⁸
Slurry	Plasma	Nozzle (high energy)	Freezing	Suspension Plasma-spraying ( = atomization)⁸⁶^-⁸⁸	0.01–100 μm	HA ⁸⁶ ^- ⁸⁸
	Gas (Aerosol)	Nozzle (high energy)	Drying	Spray-drying⁷⁵^,⁹⁶^,¹⁰⁵^,¹⁰⁷^,¹¹⁷^,¹²⁶^,¹³²^,¹⁴⁷^,¹⁶⁷^-¹⁷¹	0.4–240 μm	DCP ¹⁶⁷
						β-TCP ¹⁰⁵ ^, ¹⁷¹
						HA ⁷⁵ ^, ⁹⁶ ^, ¹⁰⁷ ^, ¹¹⁷ ^, ¹²⁶ ^, ¹³² ^, ¹⁴⁷ ^, ¹⁶⁸ ^- ¹⁷¹
	Gas + liquid	Nozzle (high energy)	Freezing	Freeze granulation¹⁰⁴	0.4–240 μm	HA ¹⁰⁴
		Nozzle (low energy)	Gelling⁶²^,⁶⁵^-⁶⁹^,¹⁷²	Drip casting⁶²^-⁷¹ ( = Droplet extrusion)	100–4000 μm	BCP ⁷⁰ ^, ⁷¹
			Freezing⁶³^,⁷⁰^,¹⁷³			HA ⁶² ^, ⁶⁴ ^- ⁶⁸ ^, ¹⁷²
			Drying⁶⁴			β-TCP ¹⁷³
	Liquid	Propeller	Precipitation⁷³^,⁷⁵^,⁷⁹^-⁸²^,¹⁰⁶^,¹⁷⁴	Emulsification⁷²^-⁸²^,¹⁰⁶^,¹⁰⁸^,¹⁷⁴^–¹⁷⁶	50–6000 μm	DCPD ⁷³ ^, ¹⁰⁶
			Gelling⁷²^,⁷⁴^,⁷⁶^-⁷⁸^,¹⁷⁵			BCP ⁸²
						HA ⁷² ^, ⁷⁴ ^, ⁷⁵ ^, ⁷⁷ ^- ⁸¹ ^, ¹⁰⁸ ^, ¹⁷⁴ ^– ¹⁷⁶
						Fluoroapatite ¹⁷⁵
	Liquid + liquid	Nozzle (low energy)	Gelling	Hydro-casting⁸³	> 1000 μm	α-TCP ⁸³
	Solid	Template or mold	Drying	Lost wax⁸⁴^,⁸⁵^,¹²¹	300–3000 μm	BCP ¹²¹
						HA ⁸⁴ ^, ⁸⁵
Paste	Gas	Propeller	Drying	Spray-granulation⁸⁹^,⁹⁰ (high-shear mixing)	100–8000 μm	DCPD ⁸⁹
						HA ⁹⁰
		Sieve	Drying	Extrusion-spheronization⁸⁹^,⁹¹	500–2000 μm	DCPD ⁸⁹
						HA ⁹¹
		Sieve	Drying	Sieve-shaking⁹²	> 500 μm	HA ⁹²
Powder	Plasma	Nozzle	Freezing	Plasma melting⁴⁵^,⁴⁶^,⁹⁴^-⁹⁷	5–125 μm	HA ⁹⁴ ^- ⁹⁷
				( = Combustion flame spraying = Flame spherodization)		TetCP ⁴⁵ ^, ⁴⁶

The column entitled “method name” contains one or several names used to call the production method. The production methods are either based on solutions, slurries, pastes, or powders. Here, a difference is made between slurries (low-viscosity, free-flowing) and pastes (high viscosity). Formation of spherical particles occurs either in a plasma, a gas, a liquid or a solid using nozzles, propellers, sieves, or templates. A “high energy” dispersion is used to describe a highly turbulent dispersion regime, in contrast with a “low energy” dispersion regime occurring in laminar flow conditions. The consolidation steps may involve precipitation, drying, pyrolysis, gelling, or freezing. The diameter may range between 0.01μm and a few millimeters. Finally, all types of CaP phases can be produced, but not all methods can be used to produce one particular CaP phase. This table is only considering published methods used to produce CaP particles. Many other methods have been proposed, in particular with pelletizers¹⁵⁴^,¹⁵⁵ and bottom-up approaches⁹⁸ such as 3DP.⁹⁹^,¹⁰⁰