top of page

CENTRAL MIXING STATION FOR HOSPITALS



Hospital compounding plants are facilities for medium and high complexity institutions. The main purpose is the safe, standardized and controlled preparation of sterile drugs, mainly parenteral solutions, parenteral nutrition, chemotherapy mixtures and other drugs that require special handling conditions. The aim of these plants is to guarantee not only the accuracy of the dosage and the quality of the final drug, but also the protection of the personnel performing these tasks and of the patient who will receive the product.



Central Mixing Plant Hospital San Javier
CENTRAL MIXING PLANT - SAN JAVIER HOSPITAL











Central mixing station for hospitals



In essence, a central mixing plant is understood as a laboratory for the preparation of drugs under strictly controlled conditions, both in terms of sterility and accuracy in the composition of the preparations. These facilities are not improvised or arbitrarily adapted to pre-existing spaces. Their design and construction are governed by international standards, such as USP <797> and <800> guidelines, as well as good sterile preparation practice (GPP) guidelines, ISO standards for clean rooms and country-specific local regulations.


From a constructive point of view, a blending plant must have differentiated and clearly delimited areas according to the process flow and the type of preparation. Generally, there is an input reception area, a storage area, a preparation area, the clean room where the actual blending takes place, and a control and dispatch area. The clean room is the heart of the plant and is built under clean architecture criteria: smooth surfaces, without joints or cracks, made of materials resistant to disinfectants, and with a design that minimizes the accumulation of particles and facilitates cleaning.



The controlled environment is an absolutely essential component in these facilities. The mixtures that are prepared are administered directly into the patient's vascular system, without passing through the body's natural barriers, which makes them high-risk products in microbiological terms. To mitigate this risk, the environment must be strictly controlled in terms of positive or negative pressure (depending on the type of preparation: e.g. positive for nutrients and negative for cytotoxics), temperature, relative humidity, air flow and level of suspended particles in the environment.

These conditions are achieved through the implementation of specialized HVAC systems (heating, ventilation and air conditioning), with high efficiency HEPA filters, which allow maintaining ISO 7 or 8 room classifications in the support areas, and ISO 5 within the laminar flow cabinets or biological safety cabinets where mixing is carried out. These cabinets not only ensure an ultra-clean environment for product handling, but also protect the operator in case of working with hazardous substances, such as oncological drugs.




The existence of a central mixing center within a hospital is not only an added value, but a necessity when aiming for safe, effective and quality-standard care. The centralized system allows complete traceability of each preparation, from medical prescription to patient administration, including pharmaceutical validation, batch registration, control of environmental conditions and supervision of each step of the process. It also reduces the margin of human error and limits the exposure of nursing staff to risk by avoiding the handling of drugs in clinical units.








From the manufacturing side, we work closely with hospital pharmacists, biomedical engineers and hospital management teams. The objective is to ensure that the infrastructure not only meets regulatory requirements, but also responds to the specific operational and logistical needs of each institution. Therefore, a sizing study is carried out according to the expected volume of preparations, type of drugs to be handled, work shifts and level of automation to be implemented.



In some cases, the plant may include robotic systems for the preparation of mixtures, especially in large hospitals. These automated systems, although costly, offer exceptional levels of accuracy and safety, reducing personnel exposure to hazardous substances and minimizing the risk of contamination.

In addition to the physical and environmental design, the operation within a compounding plant implies a rigorous organization of the workflow, with standardized protocols for each type of preparation. These protocols are developed by the hospital pharmacy service and must be aligned with pharmacological, pharmacokinetic and pharmacodynamic regulations. Each drug being handled has its own requirements for stability, compatibility, sensitivity to light or temperature, and shelf life after reconstitution or mixing. All this must be considered from the moment the plant layout is designed to the training of personnel.

Central mixing station for hospitals

In addition to the physical and environmental design, the operation within a compounding plant implies a rigorous organization of the workflow, with standardized protocols for each type of preparation. These protocols are developed by the hospital pharmacy service and must be aligned with pharmacological, pharmacokinetic and pharmacodynamic regulations. Each drug being handled has its own requirements for stability, compatibility, sensitivity to light or temperature, and shelf life after reconstitution or mixing. All this must be considered from the moment the plant layout is designed to the training of personnel.



CENTRAL MIXING PLANT - SAN JAVIER HOSPITAL


For example, the preparation of parenteral nutrition, which requires a precise mixture of macronutrients and micronutrients, requires a detailed knowledge of the physicochemical principles that affect the stability of lipid emulsions, the compatibility of calcium-phosphate solutions, and the sensitivity of certain vitamins to oxidation. These mixtures are made under total aseptic conditions, usually inside a class II laminar flow hood type A2 or B2, depending on the characteristics of the compound.


On the other hand, when handling oncological or cytotoxic drugs, a specific infrastructure with controlled negative pressure, dedicated exhaust fans with secondary HEPA filters and physical containment areas, such as class II or III biological safety cabinets, is required. In these cases, the design seeks not only to protect the product, but also to protect the operator and the environment from possible exposure to highly toxic agents. These areas require daily decontamination procedures, constant monitoring of differential pressure between zones, and redundant filtration and ventilation systems.













Central mixing station for hospitals

Continuous environmental monitoring is one of the cornerstones of quality assurance. It is not enough to build a clean room with the appropriate filters: it is essential to monitor in real time the air's microbial load, suspended particles, differential pressure between critical areas, temperature and relative humidity. For this purpose, sensors connected to automated management systems (BMS: Building Management System) are installed, which issue alerts when any parameter deviates from the established range. This allows immediate action to be taken to prevent contamination of a mixture or interruption of a critical batch.

CENTRAL MIXING PLANT - SAN JAVIER HOSPITAL




In parallel, microbiological monitoring practices of the environment, surfaces, gloves, and personnel are implemented on a routine basis, using sedimentation plates, swabs, or contact tests. This is part of the environmental validation program, which should consistently demonstrate that the area is suitable for sterile drug preparation.




Process validation is another indispensable component. Every procedure must be subjected to media fill tests, where the preparation process is reproduced using sterile culture media instead of real drugs. These tests verify the asepsis of the process, the competence of the personnel and the integrity of the sterile barrier system. Mixing plants should perform these tests on a regular basis and whenever new personnel are hired or critical procedures are modified.
In terms of traceability, every modern compounding plant must have a computerized management system to record every step of the process: from validation of the medical prescription, the selection and batch of the input, the operator who made the mixture, the environmental conditions at the time of preparation, to the final labeling and the expiration date of the product. This not only facilitates internal and external audits, but is also a requirement for active pharmacovigilance and risk management.


Staff training is another key factor in the efficiency of a plant. Operators-usually pharmacy technicians, under the direct supervision of a clinical pharmacist-must be rigorously trained in aseptic handling techniques, one-way flows, cross-contamination control, proper use of PPE (personal protective equipment), and emergency protocols in case of spills or accidental exposure. In addition, they must undergo regular retraining and proficiency testing, as human error in a highly controlled environment can have severe clinical consequences.


MACHINE ROOM, CENTRAL MIXING PLANT : SAN JAVIER HOSPITAL

Central mixing plant

From a broader perspective, central compounding centers represent a profound transformation in the way hospital pharmacotherapy is handled. They make it possible to move from a decentralized model, where each clinical unit handles and mixes drugs at the patient's bedside, to a centralized model, where all preparations are carried out under strict quality, control and biosafety standards. This, in addition to reducing the risk of medication errors and increasing efficiency, frees up nursing staff time and improves hospital response times.



Another important aspect that is emerging is the integration of these centers with electronic prescription systems, dispensing automation and traceability with RFID technology or barcodes. These tools allow even finer control of the flow of medication, from preparation to administration, reducing the margin of error at each point in the process.

With all these elements together - infrastructure, controlled environment, process validation, continuous training and digital traceability - the compounding center becomes not only a physical space, but also a complex pharmaceutical quality management system.




Automation Systems



One of the most important components of a mixing plant is undoubtedly the HVAC (Heating, Ventilation and Air Conditioning) system. Unlike a conventional air conditioning system that is limited to maintaining thermal comfort, in a mixing plant the HVAC plays an essential role in biosafety, contaminant control and preservation of environmental sterility.


The air conditioning system in these environments must be designed with surgical precision. The aim is not only to control temperature and humidity, but also to ensure laminar airflow, differential pressure between zones, high efficiency filtration and constant air renewal with controlled flow rates. All this in order to comply with ISO 14644 standards for clean rooms and good practice guidelines (GMP) applicable to the preparation of sterile products.



To achieve this, real-time automation and monitoring systems are implemented, usually integrated into a BMS (Building Management System). These systems allow continuous control over critical environmental variables such as:


  • Differential pressure between areas (e.g., maintain positive pressure in sterile mixing areas to prevent ingress of particles from less clean areas, or negative pressure in the handling of hazardous drugs to contain contaminants).


  • Temperature and relative humidity, which must be kept within very strict ranges (usually between 20 and 24°C, with a humidity of 30% to 60%) to ensure drug stability and operator comfort.


  • Air flow speed and direction, especially in laminar flow or biological safety cabinets, where the flow must be unidirectional and laminar, without turbulence, to avoid particle recirculation.


  • Airborne particle count, which is a requirement to maintain the ISO classification of the rooms (ISO 5 inside booths, ISO 7 or 8 in adjacent areas).



MACHINE ROOM, CENTRAL MIXING PLANT : SAN JAVIER HOSPITAL


These automation systems include sensors distributed at strategic points that transmit data to a centralized server or a digital interface accessible to technical and pharmaceutical personnel. Any deviation from the preset parameters triggers an immediate alarm, either visual, audible or digital, which forces the process to be interrupted if necessary. In addition, all data is automatically recorded and stored, allowing historical traceability, trend analysis and regulatory audits.


An advanced feature of some systems is the automation of the access control system, which is linked to differential pressure. That is, if the pressure between two areas is not adequate, the doors cannot be opened simultaneously. This logic avoids cross drafts and ensures the integrity of the clean environment. These systems can include biometric readers, RFID cards or even proximity sensors to limit entry to authorized personnel only.
HEPA filter monitoring systems are also integrated, which indicate in real time the saturation level of the system's terminal filters and pre-filters, triggering alerts when replacement is necessary. This is critical, as the performance of the filtration system is the first barrier against microbial and particulate contamination.


Beyond HVAC, there are other equally relevant automation systems. One of them is the pharmaceutical production management system. This system is connected to electronic medical prescription, pharmaceutical validation systems and traceability of supplies. It can print labels with unique barcodes for each preparation, manage batches, control expiration dates, validate compatibilities and record the history of each mixture.


CENTRAL MIXING PLANT - SAN JAVIER HOSPITAL

In the most technologically advanced plants, robotic mixing systems are implemented, especially for the preparation of chemotherapy or parenteral nutrition. These robots work in controlled environment conditions, reducing human manipulation to a minimum, which translates into greater precision and less risk of error or contamination. Automation of this type not only improves safety, but also increases efficiency and allows the volume of preparations to be scaled up without compromising quality.


Another aspect to consider is the integration of hospital information technology (HIS) with the central mixing station. This integration ensures that all information - from the medical order to patient administration - is synchronized in real time. This avoids duplication, reduces errors and guarantees evidence-based pharmacotherapy and control.


The energy component cannot be left out of this scenario. These systems must have redundant power sources, such as dedicated power plants or UPSs, to ensure continuity of operation of the HVAC, monitoring systems and safety cabinets in case of power grid failures. The stability of the environment cannot be compromised, even for a few minutes, as it could mean the loss of expensive medications or risk to a patient's life.

Finally, an element that is often underestimated is the preventive maintenance and periodic validation of all systems. A central mixing plant may be built to the highest standards, but without rigorous maintenance and recurring validations - of air flow, particle counts, filter integrity testing, process simulations, sensor and software review - there is a risk that patient safety will be compromised over time. Automation also facilitates this task, as systems can generate scheduled reports, schedule calibration reminders, and maintain automated records that meet regulatory requirements.




Hazardous waste management


In a mixing plant, particularly when handling cytotoxic drugs, antineoplastic drugs, biological agents, or even substances with high pharmacological concentration (such as anesthetics or hyperosmolar solutions), waste is generated that must be treated as biohazardous, infectious or chemical waste. These wastes, if not properly managed, represent a high risk to staff, patients, the environment and may constitute a legal non-compliance.


The management of these wastes begins with the design of the facility. The plant must have a specific area for the handling, classification, temporary storage and removal of waste. This area should be physically separated from the preparation area to avoid cross-contamination. In addition, it should be easily accessible to removal teams, but restricted to unauthorized personnel.


There are several types of waste generated in a blending plant, and each requires a particular treatment:


  • Cytotoxic and antineoplastic wastes, including partially used vials, syringes, needles, empty vials, contaminated infusion bags and cleaning materials (towels, gloves, gowns) that have had contact with these compounds. These should be placed immediately after use in rigid, airtight, puncture-resistant containers, marked with the cytotoxic symbol and managed as special hazardous waste according to local legislation or standards such as NTP 905, OSHA or PAHO's Manual of Good Handling Practices for Cytotoxics.


  • Contaminated liquid wastes, such as spills of drug solutions, are collected using specific absorbent kits and are also disposed of as hazardous waste. They should not be discharged into common drains, as they contaminate the water system and can affect sensitive organisms even at minimal concentrations.


  • Used HEPA filters, personal protective equipment (PPE) and other maintenance waste, if they have been in contact with hazardous drugs, should be considered as chemical or infectious waste depending on the exposure context.



MACHINE ROOM, CENTRAL MIXING PLANT : SAN JAVIER HOSPITAL


All personnel working at the plant must be specifically trained in the safe handling of hazardous waste. This includes knowing the types of waste, the protective equipment needed to handle them, the maximum time they can remain in the temporary storage area, and the protocols in case of spills or accidents.


It is essential to have a spill contingency plan. This includes the availability of spill kits at strategic points in the plant, which should contain thick nitrile gloves, a mask, eye protection, an impermeable gown, hazardous waste bags, absorbent material and rigid containers. Personnel should know how to act quickly and follow a procedure sheet validated by the hospital biosafety committee.



In addition, all waste must be labeled, classified and recorded in specific logs that allow control over the quantity, type of waste, date of generation and date of collection. In accredited or highly complex hospitals, this waste traceability system is supervised by the environmental health area and in many cases is carried out digitally.






Temporary storage must comply with clear technical characteristics: adequate ventilation, chemical-resistant surfaces, visible signage, appropriate lighting, controlled temperature and secondary containment systems in case of spills. Storage must not exceed the times established by the regulations (usually no more than 48 to 72 hours for hospital hazardous waste), and must have a contract with an authorized external company for collection and final disposal.


Final disposal is carried out by certified waste management companies that transport the waste under safety standards and destroy it through processes such as high-temperature incineration or alternative technologies such as plasma treatment or encapsulation. These companies must provide certificates of final disposal, which are part of the documentation required in sanitary and environmental audits. Finally, it is necessary to establish a periodic evaluation of the waste management program, including internal audits, analysis of nonconformities, review of incidents and drills. The central mixing plant should be an environment of continuous improvement, where biosafety is managed with the same rigor required for pharmaceutical quality.



CENTRAL MIXING PLANT - SAN JAVIER HOSPITAL


Biosafety and traceability are fundamental issues, the construction of a mixing plant cannot be left to chance or rely on improvised solutions. A highly specialized technical intervention is required, capable of integrating not only a high-level physical infrastructure, but also the intelligent systems and equipment necessary to ensure that each pharmacological mixture is carried out under the strictest conditions of environmental control, safety and quality.


At INPAL, we are dedicated to design, build and implement state-of-the-art hospital compounding plants, based on international standards such as ISO 14644, USP <797> and <800>, and with a deep understanding of the hospital pharmaceutical operational flow. Beyond the civil or architectural work, our focus is on the functional engineering of the environment, and the integration of specialized technology that guarantees sterile, safe and traceable spaces from the first day of operation.

We implement highly automated systems, with differential pressure control between areas, terminal HEPA filtration, real-time environmental monitoring and centralized digital management. This allows us to maintain the appropriate cleanroom classification in each zone (ISO 7, ISO 8, and ISO 5 in cabins), actively minimizing the presence of particulate and microbiological contaminants. We incorporate distributed sensors, motorized valves, automated airlock doors and warning systems that guarantee an environment always within safe parameters.



MACHINE ROOM, CENTRAL MIXING PLANT : SAN JAVIER HOSPITAL

In addition, we integrate laminar flow cabinets, class II B2 biological safety cabinets, weighing cabinets and aseptic workstations, all connected to an intelligent monitoring network that allows the hospital to have full visibility of operating conditions, record every step of the process and react in real time to any deviation.

We know that a compounding center is not just a space, but a living system that must be sustained with technical reliability over time. That is why we design our solutions with a long-term vision, incorporating pharmaceutical automation options, electronic traceability, integration with HIS systems and medical prescription platforms, and scalable components to adapt to the growth of the institution.


In a hospital where the patient's life literally depends on every milliliter prepared under sterile conditions, our job is to build spaces that not only comply with the norm, but also exceed the standards and become a benchmark for safety, efficiency and technology applied to healthcare.






INPAL | Engineering for Clean Environments
INPAL | Engineering for Clean Environments



Tel: +52 55-1114-8980

Wa: +52 55 8255 8084


Comments

Rated 0 out of 5 stars.
No ratings yet

Add a rating
bottom of page