How does pharma-grade spirulina powder behave on a 27-station rotary tablet press?

Direct compression is selected for Unifarma Herbals Spirulina Plus Pharma Grade API only when the tablet target is a whole-cell oral supplement core and when the API lot has been pre-conditioned to a low moisture content. The powder typically exhibits a bulk density of 0.30–0.45 g/cm³ and a Hausner ratio above 1.30 unless a densified or co-spray-dried grade is supplied. On a 27-station rotary press running at 30–60 rpm, the main compression force for a 500 mg core is maintained between 8 kN and 14 kN; precompression is set at 2–4 kN to displace interstitial air. Exceeding 16 kN increases the incidence of chlorophyll oil exudation and punch filming, while forces below 6 kN produce friable cores above 1.0%. The formulation addition ratio is 20–50 wt% API in the core, with 30–40 wt% preferred because higher loadings push sustained-run ejection forces beyond 1,000–1,200 N. A representative direct-compression core of 500 mg contains 150–250 mg API, spray-dried mannitol 35–55 wt%, microcrystalline cellulose 12–15 wt%, crospovidone 2–4 wt%, colloidal silicon dioxide 0.5–1.0 wt%, and magnesium stearate 0.75–1.25 wt%. Magnesium stearate is added in a final external lubrication step of 3–5 min because longer blending increases hydrophobicity and retards disintegration. On production-scale bin blenders of 100–600 L, the blend is mixed at 10–15 rpm for 15–20 min after the API has been pre-dispersed with a portion of mannitol. Compression under uncontrolled humidity above 45% RH leads to picking and weight variation greater than ±3.0% RSD. The downstream sequence is dry mixing, external lubrication, compression, immediate aqueous film coating where specified, and packaging in Aclar/PVC or PVDC blisters with a desiccant canister. Compliance references include USP <905> for uniformity of dosage units, Ph.Eur. 2.9.5 for uniformity of mass, USP <2040> and Ph.Eur. 2.9.1 for disintegration, USP <1217> for tablet breaking force, and ICH Q3D for elemental impurities. End product types in this track are uncoated adult oral supplement tablets, aqueous film-coated oral tablets, and cylindrical or caplet cores for subsequent blister or stick-pack delivery.

Tamping-pin capsule filling and the low-bulk-density boundary

When the API is transferred into a size 0 capsule formulation, the low bulk density of milled spirulina powder, often 0.30–0.45 g/cm³, restricts the achievable fill weight below 500 mg unless the API is pre-densified or blended with high-density fillers. Powder-filled capsules containing Unifarma Herbals Spirulina Plus Pharma Grade API are manufactured on automatic fillers using tamping-pin or dosator technology. On a tamping-pin machine with five tamping stations, the pin compression force is kept between 50 N and 150 N per station; excessive tamping creates inhomogeneous plugs and causes capsule body splitting because the chlorophyll-rich powder has limited elastic recovery. The fill blend commonly contains 20–35 wt% API, 45–60 wt% mannitol or maltodextrin, 10–20 wt% microcrystalline cellulose, 0.5–1.0 wt% colloidal silicon dioxide, and 1.0–2.0 wt% sodium stearyl fumarate. A size 0 capsule can be filled with 250–400 mg of blend, delivering 100–250 mg API depending on shell capacity; a size 00 capsule may deliver up to 600–800 mg of blend, but weight variation must be maintained below ±4.0% RSD. The capsule filling room is controlled to 35–45% RH because hard gelatin shells become brittle below 35% RH and soften above 50% RH; HPMC shells show less brittleness but higher static charge. After filling, the capsules are polished, metal-checked, and packaged in induction-sealed HDPE bottles with silica gel. Compliance for this scenario includes USP <905> for content uniformity, USP <2040> for disintegration, USP <711> or Ph.Eur. 2.9.3 for dissolution where a claim is made, and 21 CFR 111 for dietary supplement cGMP. The end products are two-piece hard gelatin or HPMC capsules in blister-packed or bottle formats.

During aqueous fluid-bed granulation, the process window for spirulina-containing granules narrows because the API proteins denature above 40°C product temperature and phycocyanin degradation accelerates under prolonged wet heat. The granulation is run in a top-spray fluid-bed system with inlet air at 50–65°C, product temperature 30–38°C, atomization pressure 1.5–2.5 bar, and spray rate 10–30 g/min for a 10 kg batch; the binder solution is typically 3–5 wt% povidone K30 or 1–2 wt% hydroxypropyl cellulose in purified water. The finished granule moisture is dried to 1.5–3.0% loss on drying because residual moisture above 3.5% causes stickiness and granule collapse during storage, while overdrying below 1.0% increases friability and dusting. The addition ratio for the API in oral granule formulations is 10–25 wt% of the granule mass, with the balance composed of isomalt, sorbitol, maltodextrin, or sucrose as bulk fillers, 2–4 wt% crospovidone or sodium starch glycolate as disintegrant, and 0.5–1.0 wt% colloidal silicon dioxide. The process sequence includes dry pre-blending, top-spray granulation, drying to endpoint, sieving through 0.8–1.0 mm mesh, and filling into triple-layer sachets under nitrogen or vacuum. A 2 g sachet granule containing 200 mg API is a commonly selected single-dose presentation; the granule should disperse in 50–100 mL water within 60 s at 15–25°C. This scenario is governed by USP <2040> and Ph.Eur. 2.9.1 for disintegration of granules, USP <921> for water content, and 21 CFR 111 for dietary supplement production. End product types are single-dose stick packs, multi-dose granule bottles, and sachet-form oral powders for reconstitution.

When a dispersible tablet must disintegrate in ≤ 60 s without leaving chlorophyll agglomerates

Dispersible spirulina tablets require a formulation strategy that preserves rapid water uptake while preventing the chlorophyll-protein matrix from forming sticky surface gels on contact with water. The API is incorporated at 15–30 wt%, with 20 wt% as the usual starting point for a 250 mg labeled API claim in a 1,250 mg tablet. The blend uses spray-dried mannitol 40–55 wt%, microcrystalline cellulose 10–20 wt%, crospovidone 5–8 wt%, and magnesium stearate 0.5–1.0 wt%; sucrose-based bulking agents are avoided because they depress water uptake and leave sweet gritty residues. Tablets are compressed to 4–7 kp hardness at a main compression force of 5–10 kN; higher forces reduce tablet porosity and push disintegration beyond 60 s. The target disintegration time is ≤ 60 s in 900 mL water at 15–25°C, with no visible agglomerates after 120 s. Pilot runs on a rotary press equipped with 12–20 mm round or caplet tooling have shown that punch-tip lubrication and RH below 40% are critical to avoid edge picking. The production sequence is dry blending, direct compression, optional flash film coating, and packaging in perforated or peelable blister packs with desiccant. Compliance references include USP <2040> and Ph.Eur. 2.9.1 for disintegration, USP <905> for uniformity, and ICH Q3D for elemental impurities. End products are orodispersible tablets, fast-dissolving adult tablets, and dispersible tablets for reconstitution in water.

A parenteral spirulina presentation cannot be treated as a simple dilution of the oral-grade whole-cell powder because the microbial endotoxin load, insoluble cell-wall debris, and chlorophyll-lipid complexes exceed the limits of USP <788> particulate matter and USP <85> bacterial endotoxins. Any injectable development based on Unifarma Herbals Spirulina Plus Pharma Grade API therefore starts with a phycocyanin-rich aqueous fraction rather than the crude whole biomass; the fraction is dissolved in Water for Injection, pH-adjusted to 6.8–7.4, and clarified through 0.45 µm and 0.22 µm sterilizing-grade PVDF or PES filters under nitrogen. There is no harmonized compendial addition ratio for injectable spirulina; the only defensible approach is to define the concentration through an ICH Q8 design space and parenteral stability protocol, with conservative exploratory batches reported at 0.05–0.20% w/v phycocyanin-rich fraction because higher concentrations promote visible aggregation and filter fouling. Osmolality is adjusted to 280–320 mOsm/kg with sodium chloride or mannitol, and the solution is filled under ISO 14644-1 class 5 conditions. If the product is lyophilized, the fill is performed at 5 ± 3°C, freeze-dried with a primary drying shelf temperature of -25°C to -15°C and secondary drying at 20–25°C, then sealed with nitrogen. Final release testing includes USP <71> sterility, USP <85> endotoxin, USP <788> particulate matter, USP <790> visible particulates, USP <785> osmolality, and ICH Q3B for degradation products. The end product types are sterile aqueous injections for investigational use and lyophilized cakes for reconstitution. Published data for this specific injectable configuration is limited, so batch-specific process qualification is mandatory before any commercial transfer.

The coating threshold is defined by pH-dependent degradation, not by film build-up

In a Wurster fluid-bed coater, enteric coating of spirulina-containing pellets or granules is employed only when the phycocyanin fraction must bypass gastric pH and release in the proximal intestine, but the process adds heat and moisture burden that must be controlled below the denaturation threshold of the API. The pellet cores are prepared by extrusion-spheronization or by layering the API onto sugar or microcrystalline cellulose nonpareil seeds; the API loading is 15–25 wt% of the pellet mass, with 5–10 wt% microcrystalline cellulose and 1–2 wt% hydroxypropyl methylcellulose as binder. A seal coat of HPMC at 3–5 wt% solids is applied before the enteric coat to prevent migration of chlorophyll into the methacrylic acid copolymer film. The enteric coating is an aqueous dispersion of methacrylic acid-ethyl acrylate copolymer such as Eudragit L30D-55 at 20–30% solids, with triethyl citrate 10–20 wt% of dry polymer and talc 40–50 wt% of dry polymer. In the Wurster coater, the product temperature is held at 25–30°C, atomization pressure at 1.5–2.0 bar, and spray rate at 8–15 g/min per kg of pellets to achieve 8–12% coating weight gain; curing is performed at 40–45°C for 2 h. The coated pellets must resist 0.1 M HCl for 2 h without releasing more than 10% of the marker compound and must release at least 75% within 60 min in pH 6.8 phosphate buffer per USP <711> delayed-release testing. Compliance references are USP <711> for dissolution, Ph.Eur. 2.9.3 for gastrointestinal resistance, and ICH Q3D for elemental impurities. End products are enteric-coated pellets filled into two-piece capsules, enteric-coated granules in sachets, and coated pellets for compression into modified-release tablets. This pellet track should not be selected for a simple oral supplement product because the added thermal burden and polymer cost are justified only when gastric protection is a registered claim.