Dolutegravir Sodium (Tivicay, DTG, GSK1349572, CAS 1051375-19-9, C₂₀H₁₈F₂N₃NaO₅, MW 441.36 g/mol) is the sodium salt of Dolutegravir, a second-generation HIV-1 integrase strand transfer inhibitor (INSTI) developed by GSK/ViiV Healthcare and FDA-approved in August 2013 for HIV-1 infection in treatment-naïve and treatment-experienced adults and pediatric patients. Chemically, it features a carbamoyl pyridopyrazine-oxazin-olate scaffold that chelates two essential Mg²⁺ cofactors within the HIV integrase catalytic active site, blocking the strand transfer step of viral DNA integration into the host cell genome. The critical mechanistic distinction between Dolutegravir and first-generation INSTIs (raltegravir, elvitegravir) is its unique flexible binding mode: the carbamoyl pyridopyrazine-oxazin-olate ring system and the 2,4-difluorobenzyl substituent can independently adjust their conformation within the integrase active site to accommodate structural perturbations caused by common INSTI resistance mutations (e.g., Q148H/R/K, N155H, Y143R/C). This conformational plasticity means that even when key active-site residues are mutated, Dolutegravir can reorient its pharmacophore to maintain effective Mg²⁺ chelation geometry and sustained enzymatic inhibition. The result is a significantly higher genetic barrier to resistance: whereas single amino acid substitutions (e.g., N155H) confer high-level resistance to raltegravir and elvitegravir, multiple simultaneous mutations are typically required to produce clinically meaningful Dolutegravir resistance. Furthermore, Dolutegravir exhibits prolonged integrase target occupancy with a dissociation half-life of approximately 71 hours from the integrase-viral DNA complex, compared to approximately 9 hours for raltegravir and approximately 3-7 hours for elvitegravir. This exceptionally slow off-rate translates to sustained suppression of integration activity long after plasma drug concentrations decline. Unlike elvitegravir, Dolutegravir does not require pharmacokinetic boosting with cobicistat or ritonavir because its primary metabolic pathway is UGT1A1-mediated glucuronidation (not CYP3A4 oxidation), yielding a plasma elimination half-life of approximately 14 hours with once-daily oral dosing. Dolutegravir is recommended as the preferred first-line INSTI by WHO (since 2018 consolidated ARV guidelines), DHHS, and EACS guidelines for all populations. UPOR Biotech supplies Dolutegravir Sodium pharmaceutical API at ≥99% HPLC purity under c-GMP with USP/EP compliance.

The high genetic barrier to resistance is the defining clinical advantage of Dolutegravir over first-generation INSTIs and arises from a combination of structural, kinetic, and thermodynamic factors. First-generation INSTIs (raltegravir, elvitegravir) bind the integrase active site in a relatively rigid conformation that is highly sensitive to structural perturbations caused by resistance mutations. A single amino acid substitution in the integrase catalytic core domain — most commonly N155H, Q148H/R/K, or Y143R/C — can reduce raltegravir susceptibility by 10- to 50-fold, resulting in virologic failure on continued therapy. Elvitegravir shares extensive cross-resistance with raltegravir due to overlapping binding modes. Dolutegravir overcomes this limitation through three synergistic mechanisms: (1) Conformational flexibility — the carbamoyl pyridopyrazine-oxazin-olate core and the 2,4-difluorobenzyl substituent can independently adjust their spatial orientation within the active site. When a resistance mutation alters the geometry of the Mg²⁺ coordination sphere (e.g., Q148H displaces one Mg²⁺ ion), Dolutegravir can shift its metal-chelating pharmacophore to re-establish effective Mg²⁺ coordination, whereas raltegravir cannot make this conformational adjustment. (2) Extended hydrophobic contacts — the 2,4-difluorobenzyl group makes extensive van der Waals contacts with the walls of the integrase active-site pocket formed by the viral DNA terminus and the catalytic triad residues (D64, D116, E152), providing a binding energy reservoir that absorbs the energetic cost of point mutations without complete loss of affinity. (3) Prolonged target residence time — the 71-hour dissociation half-life means that once Dolutegravir occupies the integrase-DNA complex, it remains bound for approximately 8-fold longer than raltegravir (t_1/2 ~9h) and approximately 20-fold longer than elvitegravir (t_1/2 ~3-7h). This kinetic stability means that even partially resistant mutants experience sustained inhibition because drug dissociation is rate-limiting for enzymatic recovery. Clinically, in the SAILING trial, no participant receiving Dolutegravir developed treatment-emergent INSTI resistance, compared to 4% of patients receiving raltegravir. In the VIKING trials, Dolutegravir 50 mg BID maintained antiviral activity against raltegravir/elvitegravir-resistant virus with multiple INSTI resistance mutations, although higher-level resistance emerged with Q148 + 2 or more secondary mutations. The requirement for multiple simultaneous mutations to produce clinically significant resistance defines Dolutegravir’s high genetic barrier and underpins its preferred status in WHO, DHHS, and EACS first-line antiretroviral therapy guidelines.

Dolutegravir Sodium exhibits a favorable pharmacokinetic profile characterized by a 14-hour plasma elimination half-life, enabling convenient once-daily oral dosing without pharmacokinetic boosting. Key parameters: Oral bioavailability approximately 70-80% (formulation-dependent) with rapid GI absorption (t_max 2-3 hours for standard immediate-release tablets). Volume of distribution (V_d) approximately 17-20 L, reflecting moderate tissue distribution with extensive plasma protein binding (>99%, primarily to albumin). The 14-hour half-life results from: (1) primary metabolism via UGT1A1-mediated glucuronidation (~53%) to an inactive ether glucuronide metabolite, with minor contributions from CYP3A4 (~5% oxidative metabolism) and UGT1A3/UGT1A9. The independence from CYP3A4 as the primary clearance route is critical — it eliminates the need for pharmacokinetic boosting (unlike elvitegravir, which is extensively CYP3A4-metabolized and requires cobicistat co-administration) and minimizes CYP450-mediated drug-drug interactions; (2) modest enterohepatic recirculation of the glucuronide conjugate; (3) renal elimination of the glucuronide metabolite accounting for approximately 30-35% of total clearance, with <1% excreted as unchanged parent drug. The linear, dose-proportional pharmacokinetics across 2-100 mg single-dose and 10-50 mg once-daily repeat-dose ranges simplify dosing. Steady state is achieved within 5-7 days of once-daily dosing. Food increases AUC by 33-66% (with moderate-fat meals); standard recommendations allow administration with or without food. Dolutegravir is a substrate of UGT1A1, UGT1A3, UGT1A9, CYP3A4, and P-glycoprotein (P-gp). UGT1A1 polymorphisms (e.g., UGT1A1*28 reduced-function allele) may modestly increase Dolutegravir exposure but are not considered clinically significant. Dolutegravir is not a clinically relevant inhibitor or inducer of CYP450 enzymes at therapeutic concentrations. However, it does inhibit the renal organic cation transporter 2 (OCT2) and multidrug and toxin extrusion transporter 1 (MATE1), which reduces metformin renal clearance (increasing metformin C_max and AUC by ~2-fold and ~1.5-fold, respectively — managed by metformin dose adjustment) and increases serum creatinine via reduced tubular secretion (a benign pharmacodynamic effect without true GFR reduction). Metal cation-containing products (antacids containing Al³⁺/Mg²⁺, calcium carbonate, iron supplements, zinc, sucralfate) can chelate Dolutegravir in the GI tract, reducing absorption; administration should be separated by at least 2 hours before or 6 hours after Dolutegravir dosing. The overall PK profile — once-daily dosing, no booster requirement, predictable linear kinetics, and a manageable drug interaction profile — makes Dolutegravir ideally suited for combination into fixed-dose single-tablet regimens (STRs) with other antiretrovirals, which is the standard of care in modern HIV therapy.

Dolutegravir is recommended as the preferred first-line integrase inhibitor by WHO (since 2018 consolidated guidelines, with 2019 update confirming favorable benefit-risk for women of childbearing potential), DHHS (US Department of Health and Human Services Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents), and EACS (European AIDS Clinical Society) based on superior performance across five critical comparison axes with first-generation INSTIs. (1) Genetic barrier to resistance: Dolutegravir requires multiple simultaneous mutations for clinically significant resistance (typically Q148H/R/K plus 2 or more secondary mutations). In contrast, single-point mutations (N155H, Q148H/R/K, Y143R/C) confer high-level resistance to raltegravir and elvitegravir. In the SAILING trial, zero Dolutegravir-treated patients developed treatment-emergent INSTI resistance vs 4% raltegravir-treated patients. (2) Pharmacokinetic boosting requirement: Elvitegravir is extensively metabolized by CYP3A4, requiring pharmacokinetic boosting with cobicistat to achieve adequate plasma concentrations and once-daily dosing. Raltegravir does not require boosting but has a shorter half-life (~9h) and requires twice-daily dosing at the standard 400 mg dose. Dolutegravir does NOT require boosting because its primary metabolic route is UGT1A1 glucuronidation, independent of CYP3A4. This simplifies treatment, eliminates cobicistat-associated adverse effects (CYP3A4 inhibition, increased serum creatinine, bilirubin elevations), and avoids cobicistat-mediated drug-drug interactions. (3) Dissociation half-life and target occupancy: Dolutegravir dissociates from the integrase-DNA complex with a half-life of ~71 hours vs ~9 hours for raltegravir and ~3-7 hours for elvitegravir. This prolonged occupancy provides sustained antiviral pressure even during brief lapses in adherence and contributes to the high genetic barrier. (4) Dosing convenience: Dolutegravir 50 mg once daily (QD), unboosted, compared to raltegravir 400 mg twice daily (BID) or elvitegravir 150 mg QD only with cobicistat boosting. Once-daily, unboosted dosing improves long-term adherence, the single most important behavioral determinant of virologic suppression. (5) Guideline preference and global adoption: The universal guideline endorsement reflects the totality of evidence from landmark trials (SINGLE, SPRING-2, FLAMINGO, ARIA, SAILING, VIKING-3/4) and large observational cohorts demonstrating superior or non-inferior efficacy, a higher barrier to resistance, and favorable tolerability compared to efavirenz, darunavir/ritonavir, and raltegravir-based regimens. Dolutegravir-containing regimens are listed among recommended initial regimens for most people with HIV by all three major guideline bodies. UPOR Biotech supplies Dolutegravir Sodium API with full c-GMP documentation to support generic ANDA development and global regulatory submissions, enabling access to this WHO-essential antiretroviral worldwide.

UPOR Biotech provides a complete c-GMP-compliant Dolutegravir Sodium API documentation package designed for seamless integration into regulatory submissions (ANDA Module 3.2.S, NDA, MAA) and customer quality systems: (1) Certificate of Analysis (COA) per batch — assay (≥99.0% HPLC), full impurity profile with RRT/RRF values, enantiomeric purity (≥99.5% ee), water content (Karl Fischer, ≤0.5%), residual solvents (ICH Q3C Class 3), heavy metals (≤10 ppm), bacterial endotoxins (≤0.5 EU/mg), and microbial panel (USP <61>/<62>). (2) Material Safety Data Sheet (MSDS/SDS) — GHS-compliant, 16-section format. (3) Signed and dated HPLC chromatogram with integration parameters, system suitability data, and Dolutegravir Reference Standard (USP/EP) traceability. (4) GMP Compliance Certificate (ICH Q7). (5) ISO 9001:2015 Certificate. (6) USP/EP Monograph Compliance Statement with individual monograph parameter conformance verification. (7) FDA Facility Registration Number. (8) BSE/TSE-Free Statement. (9) Nitrosamine Risk Assessment Report per FDA Guidance and EMA CHMP Guidance (Article 5(3) of Regulation (EC) No 726/2004). (10) Elemental Impurities Compliance Statement (ICH Q3D) with risk assessment per USP <232>. (11) Residual Solvents Statement (ICH Q3C Class 3). (12) Stability Data Package — real-time (24-month, 2-8°C) and accelerated (6-month, 25°C/60%RH) with trend analysis per ICH Q1A(R2) and Q1E. (13) Complete Lot Traceability Documentation from starting material through intermediate to finished API. (14) Genotoxic Impurity Assessment per ICH M7. (15) Enantiomeric Purity Certificate (≥99.5% ee by chiral HPLC). DMF support (Type II) is available with a Letter of Authorization for ANDA cross-reference. HALAL and KOSHER certificates provided upon request. MOQ: 1 kg for commercial orders; 100 g for R&D characterization and method development samples. Free sample available for qualified B2B buyers — contact our sales team with your company profile, intended application, and target regulatory market. All documents are provided in English; certified translations available upon request for Spanish, Portuguese, Arabic, Japanese, and Korean regulatory submissions. Our facility undergoes regular customer and regulatory audits; audit reports and quality agreements are available upon execution of a Mutual Confidentiality Agreement (MCA). UPOR Biotech offers dedicated regulatory affairs support for ANDA filers, including DMF reference, CMC query responses, and post-approval change management. Every batch is shipped with complete documentation; electronic copies are provided within 24 hours of shipment confirmation.