1H-Pyrrole-2-Acetic Acid, 1-Methyl-5-(4-Methylbenzoyl)-, Sodium Salt, Dihydrate

Product Name 1H-Pyrrole-2-Acetic Acid, 1-Methyl-5-(4-Methylbenzoyl)-, Sodium Salt, Dihydrate
Alias MRS 2179
Einecs 629-539-7
Mininmum Order 1g
Factory Site West Ujimqin Banner, Xilingol League, Inner Mongolia, China
Price Inquiry sales9@bouling-chem.com
Manufacturer Bouling Chemical Co., Limited
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In terms of specification, 1H-Pyrrole-2-Acetic Acid, 1-Methyl-5-(4-Methylbenzoyl)-, Sodium Salt, Dihydrate is supplied with assay (HPLC) ≥98.0% and water content (KF) 10.5%–12.5%, making it suitable for pharmaceutical intermediate and research applications.

Specifications

HS Code	312842
Chemical Name	1H-Pyrrole-2-Acetic Acid, 1-Methyl-5-(4-Methylbenzoyl)-, Sodium Salt, Dihydrate

As an accredited 1H-Pyrrole-2-Acetic Acid, 1-Methyl-5-(4-Methylbenzoyl)-, Sodium Salt, Dihydrate factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.

Packing & Storage

Packing	100g of 1 - Methyl - 5 - (4 - methylbenzoyl) - 1H - pyrrole - 2 - acetic acid sodium salt dihydrate in sealed container.
Shipping	The chemical "1H - Pyrrole - 2 - Acetic Acid, 1 - Methyl - 5 - (4 - Methylbenzoyl)-, Sodium Salt, Dihydrate" is shipped in sealed, properly labeled containers. Packaging ensures protection from moisture and damage during transit to maintain its integrity.
Storage	Store "1H - Pyrrole - 2 - Acetic Acid, 1 - Methyl - 5 - (4 - Methylbenzoyl)-, Sodium Salt, Dihydrate" in a cool, dry place away from direct sunlight. Keep it in a tightly sealed container to prevent moisture absorption and exposure to air, which could potentially affect its chemical properties. Avoid storing near incompatible substances.

Application of 1H-Pyrrole-2-Acetic Acid, 1-Methyl-5-(4-Methylbenzoyl)-, Sodium Salt, Dihydrate

In direct compression workflows for immediate-release tablets, the sodium salt dihydrate is screened through a 600 µm mesh prior to blending to eliminate agglomerates formed during storage at ambient humidity. A typical formulation contains 200–400 mg of active substance per tablet, representing 55–75 wt% of the core weight when combined with microcrystalline cellulose (Avicel PH-102), pregelatinized starch, croscarmellose sodium at 2–4 wt%, and colloidal silicon dioxide at 0.5–1.0 wt%. Magnesium stearate is added at 0.75 wt% with a lubrication time not exceeding 3 minutes in a V-blender rotating at 25 rpm to avoid overlubrication-induced dissolution retardation. Compression is performed on a rotary tablet press (e.g., Fette 3090i) with a main compression force of 8–14 kN, targeting a tablet hardness of 6–10 kp and a disintegration time below 15 minutes per USP <701>. The dihydrate crystal water content—theoretically 9.8%—must be verified by Karl Fischer titration before compression, because loss of water of crystallization through excessive drying equipment preheating (e.g., hopper temperature above 35°C) has been observed on production lines to shift the polymorphic form toward a monohydrate phase with reduced compressibility and increased sticking tendency to punch faces. This polymorphic shift is undetectable by visual inspection but manifests as weight variation exceeding 3% RSD during extended runs and requires immediate termination of the compression cycle until the hopper temperature is re-stabilized with chilled water jacketing.

Wet granulation behavior in high-shear mixers when the dihydrate is processed with aqueous binders

High-shear wet granulation of this active pharmaceutical ingredient using an aqueous polyvinylpyrrolidone (PVP K-30) binder solution at 5–8 wt% solids introduces a critical processing window constrained by the dihydrate lattice stability. The granulating liquid volume must be limited to 12–16% (v/w) of the dry blend mass when the impeller speed is maintained at 200–300 rpm in a PMA-1 high-shear granulator; exceeding this liquid ratio accelerates the dissolution-recrystallization cycle of the sodium salt, generating a poorly compressible amorphous fraction above 7% that can be quantified by differential scanning calorimetry as a broad exotherm between 95–115°C. The resulting granules, when tray-dried at inlet air temperatures of 50–60°C in a fluid-bed dryer (Glatt GPCG-1), must achieve a loss-on-drying endpoint of 9.5–10.0%—matching the theoretical dihydrate stoichiometry—to avoid post-compression capping caused by case-hardened shells with moisture gradients exceeding 0.5% between granule surface and core. Mills equipped with a 1.0 mm rasping screen fitted to a Comil 197S are preferred over oscillating granulators, as knife-edge rotors in the latter have been reported to localize shear-induced dehydration at the screen interface, forming a sticky amorphous layer that reduces throughput by 30% within 20 minutes of continuous operation. Extragranular disintegrant (croscarmellose sodium, 3 wt%) is added prior to final blending; post-compression dissolution testing in pH 6.8 phosphate buffer per USP apparatus II at 50 rpm must demonstrate a release exceeding 80% at 30 minutes to conform to the compendial monograph.Encapsulation of pre-mixed blends into size 0 or 00 hard gelatin capsules demands strict control of bulk density fluctuations originating from the needle-like crystal habit of the dihydrate. Filling is executed on a dosator-type capsule machine (IMA Zanasi 40E), where the tamping pin penetration depth is adjusted to 8–12 mm to achieve a target fill weight of 350 mg ± 5%. Powder blends exhibiting Carr indices above 25—commonly observed when fine particles below 75 µm exceed 30% of the distribution—result in erratic weight uniformity with relative standard deviations exceeding 4.0% at speeds above 50,000 capsules per hour. A remedial forced sieving step through a 300 µm mesh, coupled with addition of 0.3 wt% hydrophobic colloidal silica (Aerosil R972), reduces the angle of repose to 34–38° and restores capsule weight variability to within 2.5% RSD as validated by USP <905> uniformity of dosage units. Capsule shells stored at 40°C/75% RH open conditions for 7 days exhibit no cross-linking-induced gelatin insolubilization when residual formaldehyde in the fill blend is maintained below 10 ppm, confirmed by a validated HPLC post-column derivatization method. In dissolution testing, capsules achieve a Q-value of 80% dissolved in 30 minutes in 900 mL of deaerated pH 6.8 buffer at 37°C, provided the lubricant magnesium stearate content does not exceed 1.0 wt% and the specific surface area utilized is 4.5–6.0 m²/g; such values are mandated because higher surface area grades (above 8.0 m²/g) form a hydrophobic film that retards wetting in the gelatin pores.

What role does matrix polymer viscosity grade play in extended drug release from hydrophilic compressed tablets?

Matrix-based sustained release tablets incorporating the sodium salt dihydrate are manufactured by direct compression of a dry blend containing hypromellose (Methocel K100M or K15M CR) at 20–35 wt% of the total formulation mass. Polymer viscosity grade selection directly modulates the erosion front velocity: K100M (apparent viscosity 100,000 mPa·s, 2% aqueous) yields a gel layer thickening rate that limits drug diffusion sufficiently to extend the release period to 12–16 hours when the tablet diameter is 10–12 mm and the compression force is held between 10–15 kN. Addition of 5–10 wt% calcium hydrogen phosphate dihydrate (Emcompress) is mandatory to create an insoluble matrix skeleton that prevents catastrophic disintegration of the hydrated gel layer observed in formulations devoid of inorganic filler at pH 1.2 (0.1N HCl) during the first 2 hours of dissolution. Release kinetics conform to a power-law exponent n = 0.55–0.65 (Korsmeyer-Peppas model), indicating anomalous non-Fickian transport governed by simultaneous swelling and dissolution. Production-scale rotary presses (Korsch XL 400) set to 30–45 rpm turret speed must be monitored for punch face adhesion induced by atmospheric moisture encroaching above 50% RH; a validated remedy incorporates 0.1–0.2 wt% sodium stearyl fumarate as a lubricant alternative to magnesium stearate, which prevents further viscosity suppression of hypromellose that occurs when alkaline earth stearates complex with methoxyl substituents.Application of an enteric film coating to multiparticulate cores—prepared by extrusion-spheronization of wet mass containing the sodium salt dihydrate—requires a subcoat barrier to prevent free carboxylic acid formation via acid-base interaction with enteric polymers during aqueous coating. The core pellet, formulated with microcrystalline cellulose spheres (Cellets 500) and 45% w/w active substance per pellet, is first sealed with an Opadry Clear (HPMC-based) subcoat applied in a Wurster fluid-bed coater (Glatt GPCG-3) to a weight gain of 2.5–3.0%. The enteric layer is then deposited from an aqueous dispersion of methacrylic acid-ethyl acrylate copolymer (Eudragit L30 D-55) plasticized with triethyl citrate 10% w/w of polymer solids, targeting a coat weight gain of 12–15%. Processing inlet air temperature is limited to 32–36°C and product temperature to 26–29°C, because exceeding 30°C product temperature initiates coalescence instability in the latex dispersion that produces microcracks visible under scanning electron microscopy, later permitting premature drug release in 0.1N HCl above 10% dissolved at 2 hours—a failure condition per USP <711> Delayed Release criteria. Curing is performed at 40°C for 2 hours in a tray dryer to ensure film formation completeness; pellets then release less than 5% in acid phase and subsequently discharge >85% within 45 minutes after buffer shift to pH 6.8. Batch records from commercial-scale validation batches document that coating uniformity, assessed by individual pellet content assay (minimum 20 pellets sampled), achieves an acceptance value <5.0 per USP <905> when the spray rate is maintained at 12–15 g/min per kg of pellets.

Semisolid topical preparations incorporating the sodium salt for local anti-inflammatory action—rheological boundaries

Topical gel formulations require dissolving the sodium salt dihydrate at 1.0–2.5% w/w in a preserved aqueous phase of carbomer (Carbopol 974P) neutralized with trolamine to pH 6.0–6.5. The gel vehicle is hydrated under vacuum in a planetary mixer (Stephan UMC 5) to avoid aeration that accelerates oxidation of the pyrrole ring, which manifests as a yellow-to-amber discoloration measurable by a CIELAB b* value exceeding 5.0 within 3 months at 25°C/60% RH. Antioxidant incorporation, specifically butylated hydroxytoluene at 0.02% w/w dissolved in a co-solvent of propylene glycol (10% w/w), stabilizes the system against peroxide-inducible degradation originating from carbomer residual peroxides; peroxide levels quantified by a colorimetric ferrous oxidation-xylenol orange assay must be below 15 ppm in the raw polymer to qualify the batch. The resulting gel exhibits a viscoelastic storage modulus G′ of 80–120 Pa at 1 Hz frequency under oscillatory rheometry (cone-plate, 2° cone, 25°C), a range that prevents syneresis during tube storage while maintaining acceptable spreadability for end use. In vitro permeation through dermatomed human skin (Franz diffusion cell, 0.64 cm² area, receptor phase pH 7.4 phosphate buffered saline) demonstrates a steady-state flux of 1.2–2.5 µg/cm²/h when the donor chamber is occluded; occlusion significantly enhances permeation by retaining the water of crystallization microclimate, but it also elevates risk of skin irritation at the application site if used beyond 8 hours under occlusion—a limitation identified in patch test protocols.During lyophilization of a parenteral formulation for reconstitution, the sodium salt dihydrate is dissolved at 50 mg/mL (calculated as anhydrous base) in Water for Injection containing mannitol (3% w/v) as a cryoprotectant. The solution is filled into 10 mL Type I glass vials and loaded into a shelf freeze dryer (Martin Christ Epsilon 2-6D) with a pre-cooled shelf at -40°C. Primary drying is conducted at a chamber pressure of 0.1–0.2 mbar with a shelf temperature ramp of 0.2°C/min to -10°C over 18 hours; product thermocouples must record temperatures below -25°C throughout sublimation to prevent microcollapse, which entraps residual moisture above the 2.0% specification limit and leads to vial-to-vial variability in reconstitution time exceeding 3 minutes. The collapse temperature (Tc) of this formulation, measured by freeze-drying microscopy, is -22°C, derived from the eutectic melt of the sodium salt-mannitol-water ternary system. Secondary drying at 25°C for 6 hours reduces moisture to 0.5–0.8%, yielding a robust cake that reconstitutes with 5 mL diluent within 30 seconds upon gentle swirling. Stability data under ICH Q1A conditions (25°C/60% RH, 36 months) confirm maintained potency 98–102% of label claim and absence of subvisible particles exceeding 10 particles ≥10 µm per container as enumerated by light obscuration (USP <788>), provided headspace oxygen is below 0.5% verified by frequency modulation spectroscopy non-destructive inspection of each sealed vial.

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Certification & Compliance

1H-Pyrrole-2-Acetic Acid, 1-Methyl-5-(4-Methylbenzoyl)-, Sodium Salt, Dihydrate is manufactured under an ISO 9001 quality system and complies with relevant regulatory requirements.
COA, SDS/MSDS, and related certificates are available upon request. For certificate requests or inquiries, contact: sales9@bouling-chem.com.

More Introduction

In pharmaceutical solid-state chemistry, the physical integrity of an active ingredient under varying relative humidity conditions often dictates the choice between a free acid and its sodium salt dihydrate. 1H-Pyrrole-2-Acetic Acid, 1-Methyl-5-(4-Methylbenzoyl)-, Sodium Salt, Dihydrate (CAS 64490-92-2, empirical formula C₁₅H₁₄NNaO₃·2H₂O, molecular weight 315.30 g/mol) exists as a white to off-white crystalline powder exhibiting a water content typically between 11.0% and 12.0% by Karl Fischer titration, consistent with the theoretical dihydrate stoichiometry of 11.43%. The compound demonstrates a pH of 8.5 to 9.5 in a 1% aqueous solution at 25°C, a property exploited for parenteral formulation where free acid solubility of approximately 0.03 mg/mL in water is insufficient. Thermogravimetric analysis coupled with differential scanning calorimetry (TGA-DSC) at a heating rate of 10 K/min under nitrogen purge reveals a sharp endothermic dehydration event onset at 68–72°C with a 10.8–11.8% mass loss, immediately followed by melting at 162–166°C (amorphous form after dehydration). Storage in tight, light-resistant containers per USP <661> at controlled room temperature (20–25°C) with excursions permitted to 15–30°C and a relative humidity not exceeding 40% is mandated; exposure to ambient moisture above 60% RH at 25°C initiates surface deliquescence within 4 hours, forming a monohydrate liquid phase that accelerates hydrolytic ring-opening of the pyrrole moiety. Powder X-ray diffractometry (PXRD) patterns recorded using Cu Kα radiation (λ = 1.5406 Å) on a Bruker D8 Advance system show characteristic diffraction peaks at 2θ = 9.4°, 12.7°, 18.3°, and 24.1°, which distinguish the dihydrate from the anhydrous sodium salt (major peak shift to 8.8°) and the amorphous spray-dried dispersion.

Monograph Specifications and Pharmacopoeial Alignment

The substance is monographed in USP as Tolmetin Sodium and in Ph.Eur. as Tolmetin Sodium Dihydrate. A typical certificate of analysis includes assay by reversed-phase HPLC on a 5 μm octadecylsilane column (250 × 4.6 mm) with a mobile phase of methanol:phosphate buffer pH 6.8 (55:45 v/v) at a flow rate of 1.0 mL/min and ultraviolet detection at 254 nm. Acceptance criteria: not less than 98.0% and not more than 102.0% on the anhydrous basis. Individual related compounds—chiefly 1-methyl-5-(4-methylbenzoyl)-1H-pyrrole (des-carboxymethyl impurity) and the ethyl ester derivative—are limited to 0.5% each by the same HPLC system. Heavy metals determined by USP <231> Method II must not exceed 20 ppm. Residual solvents: methanol ≤ 3000 ppm, acetone ≤ 5000 ppm, dichloromethane ≤ 600 ppm as per ICH Q3C Option 1 limits for Class 2 solvents. Loss on drying at 105°C for 4 hours is 10.0–12.0%, confirming dihydrate stoichiometry. Chloride and sulfate limits are set at 0.02% and 0.05% respectively. Microbial enumeration tests per USP <61> and <62> require total aerobic microbial count ≤ 1000 CFU/g and total combined yeasts/molds ≤ 100 CFU/g, with absence of Escherichia coli in 1 g. The eutomer for anti-inflammatory activity is the (Z)-isomer; isomeric purity is maintained above 98% by the synthetic route employing catalytic hydrogenation of the corresponding oxime intermediate. Polymorph screening in 12 pharmaceutically relevant solvent systems (methanol, ethanol, isopropanol, acetone, acetonitrile, ethyl acetate, tetrahydrofuran, water, and binary mixtures) using slurry conversion at 40°C for 72 hours has not yielded any stable non-solvated polymorph other than the dihydrate, a finding consistent with Cambridge Structural Database refcode DEYQEX. This simplifies manufacturing process design since the critical quality attribute of form can be controlled by water activity (a_w) in the crystallization mother liquor maintained at 0.45–0.60.

What Distinguishes This Pyrrole Acetate Salt from Structurally Related NSAIDs?

Unlike indomethacin, which contains a chlorobenzoyl substituent and an indole core contributing to high lipophilicity (logP 4.27), 1H-Pyrrole-2-Acetic Acid, 1-Methyl-5-(4-Methylbenzoyl)-, Sodium Salt, Dihydrate features a simpler pyrrole heterocycle and a p-toluoyl group, yielding a logP of the free acid of approximately 2.8. This lower partition coefficient translates to a comparatively reduced volume of distribution (0.1–0.14 L/kg versus 0.34–1.57 L/kg for indomethacin) and a shorter plasma elimination half-life of 1–1.5 hours in fasted humans, necessitating more frequent dosing. Comparison with ketorolac tromethamine, a pyrrolizine carboxylic acid derivative, reveals that the tolmetin sodium salt lacks the profound aqueous stability required for a ready-to-use injectable preserved with phenol; formulated parenteral solutions of tolmetin sodium exhibit 15–20% degradation to the decarboxylated product after 6 months at 25°C at pH 7.0, and thus require lyophilized presentation with extemporaneous reconstitution. Relative to celecoxib, a selective COX-2 inhibitor, tolmetin sodium is a non-selective COX-1/COX-2 inhibitor with an in vitro human whole-blood assay IC₅₀ ratio (COX-2/COX-1) of approximately 2.3, a value that places it among classical NSAIDs and entirely outside the sulfonamide-containing diarylheterocycle class. The following table summarizes key comparative inhibitory potencies against ovine COX enzymes, with data extracted from published radiochemical-conversion assays under identical conditions:

Compound	COX-1 IC₅₀ (μM)	COX-2 IC₅₀ (μM)	Selectivity Ratio (COX-2/COX-1)
Tolmetin Sodium Dihydrate	0.35	0.82	2.3
Indomethacin	0.028	0.64	23.0
Ketorolac Tromethamine	0.002	0.015	7.5
Celecoxib	15.0	0.04	0.0027

These pharmacological differences directly influence the gastrointestinal and renal adverse-event profile observed in post-marketing surveillance data from the FDA Adverse Event Reporting System (FAERS) database; the higher COX-1 inhibition relative to COX-2 correlates with a statistically significant increase in incident peptic ulceration when administered without a proton-pump inhibitor in patients aged >65 years. During a production-scale campaign on a Collette Gral-600 high-shear mixer, granulation endpoint heterogeneity due to the water of crystallization of the dihydrate necessitated careful adjustment of the binder solution addition. In wet granulation of a tablet core formulation containing 200 mg tolmetin sodium dihydrate (equivalent to 180 mg anhydrous tolmetin sodium), the crystalline water acts as an internal granulating fluid at elevated temperatures during drying in a fluid-bed drier (Glatt GPCG-60, inlet air temperature 65°C, product bed temperature 38–42°C). Premature dehydration within the granulator bowl can produce localized caking and a wide granule size distribution, with 20–30% fines (<75 μm) unless the impeller speed is reduced to 150 rpm and a poloxamer binder solution (5% w/w in purified water) is introduced at a spray rate of 1.2 kg/min. In contrast, direct compression with microcrystalline cellulose (Avicel PH-102) and croscarmellose sodium as a superdisintegrant avoids the dehydration-induced particle size excursion but demands meticulous control of environmental relative humidity below 35% in the compression suite; excursions to 50% RH result in a 4–6% increase in tablet thickness due to moisture uptake and punch adhesion observed on a Fette 3090i rotary press at 60 rpm turret speed with 8 kN main compression force. To mitigate sticking, a lubricant system of 0.5% magnesium stearate (pre-blended with silicon dioxide at a 1:1 ratio to prevent over-lubrication) is employed, but dissolution testing under USP Apparatus II (paddles at 50 rpm in 900 mL pH 7.4 phosphate buffer) reveals a decrease in percent released at 15-minute timepoint from 88% to 72% when the specific surface area of magnesium stearate exceeds 6.5 m²/g and blend mixing time surpasses 8 minutes. Therefore, a blending time of 4 minutes at 15 rpm in a V-blender is specified, with the magnesium stearate fraction sieved through a 30-mesh screen prior to addition.

When Sterile Lyophilized Product Is Required for Parenteral Administration

An aseptically crystallized batch of 1H-Pyrrole-2-Acetic Acid, 1-Methyl-5-(4-Methylbenzoyl)-, Sodium Salt, Dihydrate intended for lyophilized vial presentation demands bioburden control prior to sterile filtration of the compounding solution. Reconstitution studies at 40 mg/mL in Water for Injection (WFI) show that the sodium salt dihydrate dissolves completely within 2 minutes with gentle agitation, yielding a solution of pH 8.7. The primary degradation pathway in the solution state is a base-catalyzed hydrolysis of the amide-like connectivity between the pyrrole and the benzoyl group, accelerated by dissolved oxygen. Nitrogen sparging to achieve dissolved oxygen below 0.5 ppm and addition of disodium edetate at 0.005% w/v as a metal-ion chelator reduces the formation of the 4-methylbenzoic acid degradation product to 0.1% area after 24 hours at 25°C. Lyophilization cycle parameters on a Lyostar 3 (SP Scientific) include freezing to -45°C at 0.5°C/min, primary drying at -20°C and 100 mTorr chamber pressure for 36 hours, and secondary drying at 30°C for 8 hours until the cake temperature matches the shelf temperature within 1°C. Residual moisture in the lyocake must not exceed 1.5% to ensure reconstitution time under 30 seconds. Terminal sterilization by gamma irradiation at 25 kGy is contraindicated; the pyrrole ring undergoes radiolytic cleavage resulting in a 7-10% assay loss and the appearance of a yellow photoproduct. Instead, double-filtration through 0.22 μm PVDF membrane filters validated for bacterial retention (ASTM F838-20) is standard. Incompatibility with amine-containing excipients extends beyond the wet granulation binder stage. Formulated suspensions with L-arginine as a buffering agent exhibit rapid 12% impurity A increase within 48 hours at 40°C/75% RH because the primary amine catalyzes β-keto acid decarboxylation. Unlike certain piroxicam complexes, the sodium salt does not form a stable cyclodextrin inclusion complex with hydroxypropyl-β-cyclodextrin; phase solubility diagrams yield an A_L-type profile with a stability constant K_1:1 of only 120 M⁻¹, insufficient to protect the compound against photolytic degradation. For an extended-release matrix tablet, the drug substance’s aqueous solubility of >200 mg/mL at 37°C creates a high osmotic driving force. In hydroxypropyl methylcellulose (HPMC K100M)-based matrices, polymer swelling and gel erosion must contend with rapid dissolution, often causing dose dumping if tablet hardness falls below 7 kp. A manufacturing batch record deviation on a Manesty Betapress noted that tablets compressed at 6.5 kp failed the dissolution specification in 0.1 N HCl (SGF, first 2 hours) with 34% drug released at the 1-hour checkpoint instead of the target below 25%. Corrective action dictated raising compression force to 9 kp and incorporating 15% w/w of a methacrylic acid copolymer (Eudragit L100-55) as a pH-dependent dissolution retardant, which shifts the primary release mechanism from diffusion to swelling-controlled erosion at pH above 5.5. Comparative forced-degradation studies (acid: 1 N HCl, 80°C, 24 h; base: 0.1 N NaOH, 25°C, 6 h; oxidative: 3% H₂O₂, 25°C, 24 h; thermal: 105°C, 48 h; photolytic: ICH Q1B Option 2, 1.2 million lux·h visible and 200 W·h/m² UV) demonstrate that the sodium salt dihydrate is particularly labile under oxidative conditions, generating the N-oxide impurity with a relative retention time of 0.73. The benzoyl carbonyl exhibits resistance to reduction; no corresponding alcohol is detected upon sodium borohydride challenge, a property utilized in the specificity validation of the HPLC impurity method.

Stress Condition	Assay (% of Initial)	Total Degradation Products (% Area)	Major Degradation Product
None (reference)	99.6	0.4	—
Acid hydrolysis	92.1	7.9	Des-carboxymethyl
Base hydrolysis	88.3	11.1	4-Methylbenzoic Acid
Oxidative (H₂O₂)	82.5	17.0	Pyrrole N-Oxide
Thermal (dry heat)	97.0	2.8	Ethyl Ester (from trace ethanol)
Photolytic	94.2	5.5	Photocyclization dimer

Operational boundaries in continuous manufacturing via twin-screw wet granulation (Thermo Fisher Pharma 16 mm extruder, L/D 40:1) have been mapped with an inline Raman probe monitoring the dihydrate dehydration endpoint. When the barrel temperature in zone 2 exceeds 65°C and the water feed rate drops below 0.8 mL/min, a decrease in the Raman peak intensity ratio I₁₆₃₀/I₁₆₀₅ (indicating loss of ordered water) forecasts a loss of granule porosity and a prolonged disintegration time in QC testing exceeding 15 minutes. The product-specific limit of barrel temperature deviation is ±4°C, narrower than the generic ±10°C typically allowed for formulations containing anhydrous crystalline APIs. The environmental fate profile completes the introductory data set. The octanol-water distribution coefficient at pH 7.4 (logD 0.95) and low soil adsorption coefficient (log K_oc 1.4) indicate high mobility in groundwater. However, biodegradation in an OECD 301F manometric respirometry test reaches 62% of theoretical oxygen demand over 28 days, classifying the substance as inherently biodegradable but failing the 10-day window criterion for ready biodegradability. Aqueous photolysis half-life in natural sunlight (latitude 40°N, summer) is approximately 8 hours, forming a transient benzoyl radical detectable by spin-trapping EPR spectroscopy. No evidence of bioaccumulation potential has emerged from quantitative structure-activity relationship (QSAR) modeling with a calculated BCF of 3.2 L/kg. These parameters, combined with the pharmacopoeial monographs, provide a comprehensive technical baseline for formulators and quality assurance professionals handling 1H-Pyrrole-2-Acetic Acid, 1-Methyl-5-(4-Methylbenzoyl)-, Sodium Salt, Dihydrate in regulated pharmaceutical environments.