Rare-disease treatment pathways are especially vulnerable to coordination failures because they depend on repeated treatment cycles, strict eligibility criteria, and medicines whose financial and clinical value makes diversion particularly harmful. Spinal muscular atrophy is a relevant example because it is a progressive genetic disease, often diagnosed in infancy or childhood, and its treatment has major clinical and economic implications for patients, families, and health systems [1–4]. In settings where the public sector participates in procurement or subsidized access, the consequences of weak traceability extend beyond logistics and directly affect distributive justice, clinical continuity, and public trust.

The central problem addressed in this study is not limited to counterfeit detection. In the Iranian context, the deeper challenge is the absence of an end-to-end mechanism that can connect import approval, unique medicine identification, distribution logging, patient eligibility verification, and treatment reporting within one auditable workflow. When each actor stores only a fragment of the process in separate systems, visibility becomes incomplete, oversight becomes retrospective, and the probability of diversion or undocumented allocation rises. This study therefore frames rare-drug governance as an information-integration problem as much as a pharmaceutical one.

Blockchain has attracted sustained attention in supply chain management because it can provide a distributed, tamper-resistant ledger that supports shared records, event traceability, and programmable control logic through smart contracts [5–7]. In the pharmaceutical domain, these features are attractive for provenance tracking, anti-diversion controls, and stronger accountability across multiple actors. However, the literature remains uneven. Many published studies discuss transparency, provenance, or authenticity in general terms, while far fewer propose systems that connect logistics with patient-linked allocation and downstream treatment documentation in a rare-disease setting [6–10].

This study addresses that gap by presenting a structured article extraction from that designed and evaluated a blockchain-based architecture for tracking rare and specialty medicines in Iran’s pharmaceutical supply chain. The study asks two practical questions: how blockchain can improve the current supply chain for rare-disease medicines, and which operational challenges it can reduce or introduce in the Iranian context. The contribution is not a generic conceptual framework. It is a concrete, modular architecture with defined stakeholders, modeled workflows, implemented smart contracts, and a multi-dimensional evaluation that includes functional execution, cost, scalability, usability, and user-facing transparency outcomes.

Against this background, the key research gap is the lack of a decentralized, auditable architecture that links five things at once: medicine registration, unique identifier control, distribution history, patient eligibility verification, and treatment-process documentation. Previous work explains why traceability matters and how blockchain can support it, but much less work shows how those elements can be joined in a single workflow for rare and specialty medicines under real institutional constraints [6–11], [17]. This study directly to that gap by designing a modular system for the Iranian setting and evaluating it beyond a purely conceptual level.

The study followed a design-oriented systems-engineering methodology. Rather than testing an already deployed platform, it moved from problem analysis and workflow reconstruction to artifact design, implementation, and evaluation. The approach can be summarized in four stages: identifying the current supply-chain problem and its communication bottlenecks, modeling the intended end-to-end process, implementing the blockchain-based solution, and evaluating the resulting system from technical, structural, economic, and user-centered perspectives.

Process discovery relied on a combination of literature review, informal consultations, and contextual inquiry into the current Iranian rare-drug pathway. Access to formal process blueprints from national authorities was limited because of data sensitivity and institutional restrictions. The practical workflow was therefore reconstructed from field-informed accounts and reviewed with domain specialists. This produced a stepwise representation of medicine registration, identifier assignment, distribution, clinic validation, patient allocation, physician oversight, and reporting. The reconstructed process was then modeled in BPMN to make actor roles, event sequences, and control points explicit.

The implementation stage focused on Ethereum smart contracts written in Solidity and deployed in the Remix development environment. The smart-contract layer was complemented by an application layer built with Node.js and Express.js, blockchain interaction via Ethers.js, and off-chain storage in MongoDB. The design intentionally separated public and private records. Sensitive patient and clinical information remained off-chain, while hashes and operational events were stored on-chain to preserve immutability and verifiability without exposing protected data.

Evaluation was multi-dimensional. Functional testing examined whether the contracts could execute core events correctly in a test environment [15], [16], [18]. Architectural evaluation examined maintainability and scalability under a modular contract design. Economic assessment estimated gas consumption and projected execution cost under stated public-network assumptions. User-centered assessment combined moderated usability testing, thematic analysis, quantitative task-performance review, and error analysis, drawing on well-established usability and qualitative-analysis methods [19–22]. In addition, the study also included a controlled comparative user study that contrasted the current display condition with the proposed interface for medicine availability.

The proposed system is built around six stakeholder groups: the regulator, the importer, the distributor, the clinic, the certified physician, and the patient. Each role is functionally distinct. The regulator approves medicines and oversees the chain; the importer initializes formal medicine entries and obtains unique identifiers; the distributor records movement and destination; the clinic validates identifiers and allocates medicines to eligible patients; the certified physician records post-allocation treatment evidence; and the patient accesses permitted status information. This role separation is essential because the system is not simply a logistics registry. It is a governance framework that coordinates distribution, allocation, and downstream clinical confirmation.

The workflow reconstructed in the study contains nine operational steps. First, medicine information is registered with the regulator before import. Second, a unique identifier is assigned to each unit or package. Third, medicines are transferred to distribution centers. Fourth, receiving centers verify UID validity. Fifth, receipt confirmation is logged. Sixth, eligible patients are notified. Seventh, the patient’s eligibility is checked at the clinic. Eighth, the patient is referred to a certified physician for treatment authorization. Ninth, treatment use is documented and linked back into the system. This sequence is significant because it connects the administrative and clinical phases of medicine use rather than treating traceability as a warehouse-only function.

At the smart-contract level, the architecture is modular. The DrugRegistration contract acts as the official on-chain registry for approved medicines and enforces non-reusable unique identifiers. UIDTracker records per-UID transfer records and aggregated distribution events. ClinicVerification serves as the allocation-control layer: it validates the UID against the registration registry, checks whether the patient is eligible based on the interval since the last receipt, and updates the receipt status. PublicDrugJourney makes non-sensitive distribution history available for public-facing transparency by medicine type rather than individual patient-linked identifiers. DoctorReport stores hashes of physician reports so that treatment documentation can be connected to the traceability chain without disclosing protected content.

purely on-chain.

constraints emerged, and which trade-offs remain open.

The application layer extends the contracts into a usable system. The backend follows a modular pattern in which routes direct requests to controllers, controllers call service logic, and services interact with the database and the blockchain interface. Three off-chain data domains are emphasized in this study: patient records, medicine-related records, and regional quota information. This design choice reflects a principled privacy trade-off. Hot-path governance events remain auditable on-chain, while more sensitive and mutable healthcare data stay in controlled off-chain storage. The resulting architecture is therefore hybrid rather than

The evaluation was organized around functional correctness, technical robustness, economic feasibility, architectural suitability, and user experience. This separation is important because the study’s contribution lies not only in designing the artifact but also in demonstrating which parts performed well, which

Functional validation showed that the contract set can reproduce the principal events required for rare-drug traceability. In the first scenario, the DrugRegistration contract successfully registered a medicine identifier, and duplicate registration attempts were rejected with an “already approved” logic path. This made the UID the central anchor for all subsequent supply-chain events. In the next stage, UIDTracker recorded transfer and clinic-distribution events. ClinicVerification then confirmed whether a UID was valid and whether the patient was eligible to receive the medicine at the current time. If the patient presented earlier than permitted, the logic returned a negative result; otherwise, allocation could proceed and the receipt interval was updated. At the clinical end of the chain, DoctorReport retrieved prior report hashes and recorded new ones using keccak256, so the proof of reporting was on-chain even though the source clinical document remained off-chain.

Economic testing revealed the main barrier to direct public-network deployment. For a full traceability path comprising six principal operations, the prototype consumed 635,186 gas. Under the assumptions —15 Gwei gas price and an Ether price of USD 3,000—this corresponds to approximately 0.00955 ETH, or USD 28.64 per medicine. UID registration alone consumed 185,963 gas, or roughly USD 8.36 per item under the same assumptions. Extrapolated to 2,000 rare and specialty medicines, the estimated cost is about USD 16,720 for UID registration alone and about USD 57,280 for end-to-end on-chain tracking. These numbers do not invalidate the architecture, but they strongly suggest that public Ethereum mainnet is not the economically optimal deployment target for a national health-governance use case.

Architectural analysis favored the modular design over a monolithic contract structure. For a system with multiple actors, multiple data domains, and evolving regulatory requirements, a single large contract would be difficult to test, document, debug, and upgrade. The modular pattern adopted here allows one contract domain—such as clinic verification or physician reporting—to evolve without forcing redesign of the full system. This decision improves maintainability and is especially important in healthcare infrastructures where policy and workflow requirements often change incrementally rather than all at once.

User-centered evaluation produced encouraging early evidence. Because of operational constraints during the study period, the moderated usability test was conducted with two pharmacists rather than a broader target group. Even so, both participants completed the tasks successfully. The mean task-completion times were 20 seconds and 32.5 seconds, respectively. Trust scores were high, and overall user-interface satisfaction was rated 4 out of 5 by both participants. Qualitative analysis revealed three recurring needs: clearer system messages, stronger institutional trust cues such as official visual markers, and more explicit explanations when a patient is deemed ineligible to receive the medicine.

The comparative user study reinforced the claim that the proposed design improves interpretability of medicine-availability information. The study reports that the proportion of users who believed the target medicine was available rose from 47% in the current condition to 81% in the proposed model. For quantity interpretation, 82% of users in the current condition selected “cannot be determined,” whereas that figure fell to 15% in the proposed model. In the improved interface, 61% selected the correct visible quantity. Confidence also increased markedly: 72% of users in the proposed condition reported high confidence in their answer, compared with 33% in the current condition. The study summarizes these shifts as gains of 34 percentage points in perceived availability, 58 percentage points in correct quantity interpretation, and 39 percentage points in high-confidence responses.

The study has several limitations that should be stated clearly. First, the system was evaluated at prototype level rather than in a live national deployment. Second, we did not have access to real regulatory datasets from the Ministry of Health or the national drug authority, so the workflow was reconstructed from field information and expert-informed process understanding rather than from full operational data exports. Third, some components necessarily remained off-chain because of privacy considerations. Fourth, the usability evaluation involved only two pharmacists, which limits the generalizability of behavioral conclusions even though the findings remain useful for design refinement. Finally, the public Ethereum cost analysis shows that direct mainnet deployment would likely be impractical at scale.

These limitations also define the future-research agenda. The next step is migration from a public test environment toward permissioned or hybrid blockchain infrastructures that offer lower transaction cost, stronger access control, and better institutional fit. Subsequent work should also explore interoperability with electronic health-record systems and hospital information systems so that treatment documentation can be hashed automatically rather than entered manually.

This study demonstrates that a blockchain-enabled architecture can provide a coherent and technically grounded foundation for the traceability of rare and specialty medicines in Iran’s pharmaceutical supply chain. Its main contribution lies in integrating medicine registration, UID control, distribution logging, patient eligibility verification, public traceability, and physician reporting within one modular framework. The evaluation indicates that the artifact is functionally credible and structurally valuable, while also making clear that privacy, institutional adoption, and public-network cost remain the major constraints on real-world deployment. For healthcare systems engineering, the most defensible conclusion is therefore that blockchain is not a complete solution by itself, but it can serve as a strong backbone for a more transparent, auditable, and patient-centered rare-medicine supply chain.

The author gratefully acknowledges the academic guidance received during the work, the domain experts who clarified the current medicine-distribution process, and the pharmacists who participated in the usability evaluation.

Conceptualization, M.D.; formal analysis, A.A.; Methodology, A.A.; Software, A.A.; Validation, S.C, A.A.; investigation, A.A.; resources, M.D, A.A.; data maintenance, A.A.; writing – original draft, A.A.; writing-review and editing, M.D, S.C, A.A.; visualization, A.A.; Supervision, S.C.; project administration, A.A. The authors has read and agreed to the published version of the manuscript.

No public patient-level dataset accompanies this manuscript. The study is based on a prototype system and process reconstruction. Access to real operational data from national health authorities was restricted, and sensitive patient-related content was intentionally designed to remain off-chain because of privacy considerations. Accordingly, no new public dataset was generated for open release.

The author declares no conflict of interest. Funders played no role in the design of the study, in the collection, analysis, or interpretation of the data, in the writing of the manuscript, or in the decision to publish the results.