The Spatial Distribution and Distance-Based Regulatory Compliance of Private Medicine Outlets in Two Urban Districts of Dar es Salaam, Tanzania.

Background and objective Pharmacies and Accredited Drug Dispensing Outlets (ADDOs) play a central role in expanding access to essential medicines in low- and middle-income countries. In Tanzania, national regulations mandate minimum separation distances to prevent excessive clustering and help ensure that all communities have reasonable access to essential medicines. However, the extent of compliance in rapidly urbanizing districts remains unclear. This study aimed to examine the spatial distribution of private medicine outlets (PMOs) in the Kinondoni and Ubungo districts of Dar es Salaam and assess adherence to regulatory distance requirements. Methods A cross-sectional geospatial survey was conducted across 18 urban centers. Outlet coordinates were collected through field enumeration using REDCap (Research Electronic Data Capture) mobile tools between July 14, 2019, and September 6, 2019. Official ward boundary shapefiles were obtained from the National Bureau of Statistics. Spatial patterns were analyzed by mapping PMO locations, estimating ward-level densities, calculating nearest-neighbor distances, and evaluating compliance with Tanzania's minimum-distance regulations of 150 m for same-type outlets and 500 m for ADDO-pharmacy pairs. Results A total of 377 PMOs were mapped, comprising 232 (61.5%) ADDOs and 145 (38.5%) pharmacies. The outlet distribution was highly uneven: some wards demonstrated dense clustering, while others showed sparse coverage. The median nearest-neighbor distance was 753 m, although distances ranged from <1.0 m to over 6.0 km. Overall, 110 (29.2%) of the outlets fell below the regulatory spacing thresholds. Compliance levels were similar across outlet types. Conclusions Marked clustering and substantial non-compliance with minimum distance regulations were observed in Kinondoni and Ubungo. While dense clustering may improve convenience in some neighborhoods, persistent gaps in other areas suggest emerging spatial inequities. Geospatially informed regulatory planning is required to enhance equitable access to essential medicines. The observed 29.2% non-compliance rate highlights a meaningful regulatory gap, indicating that existing minimum-distance rules are not consistently implemented. This has practical implications for market saturation, potential unfair competition, and uneven access across neighborhoods, reinforcing the need for targeted inspections and more proactive spatial oversight.