Manufacturing and Stability of Azaya’s PSN Technology

Azaya Therapeutics Manufacturing Process:

The PSN technology is unique in several ways. First, the process for generating, loading and sizing the liposomal product is a one step process. The natural excipients (phospholipids, cholesterol, protein and active ingredient) are mixed together and processed in a microfluidizer (high pressure homogenizer). The formulation mixture is processed several times until the desired particle size of <100 nm is achieved. The processed material is then is filtered (aseptic filtration) and lyophilized (concentrated) to afford a dry powder cake for final distribution.

The major advantages of Azaya’s process manufacturing include:

  1. abbreviated processing time compared to conventional methods
  2. large scope of utility (offers opportunities to formulate hydrophobic molecules) and extended product shelf life
  3. processing time is less laborious compared to conventional methods and doesn’t require the extensive quality control that has been necessary for existing processes
  4. no labor intensive gradient diffusion steps required to load aqueous soluble APIs
  5. final product will be marketed as a dry powder that is reconstituted with easy operating procedures at the physician’s office
  6. final product offers an extended shelf half life that is 5–10 fold greater than typical liposomal products
  7. broad application for the formulation of unique drug products

Generally Asked Questions about Azaya Therapeutic’s Protein Stabilized Nanoparticle (PLN) Technology

What differentiates Azaya’s PSN technology from other liposomal formulations that have been and are currently being utilized?
The technological advances made in the PSN technology are numerous and can be analyzed in further detail by focusing on each key point independently as set out below. Broadly, Azaya’s PSN technology offers significant advances compared to liposomal formulations of the last 20 + years with a simplified manufacturing process, greater variety and scope of biologically active molecules that can be formulated and delivered including water insoluble chemotherapy Active Pharmaceutical Ingredient’s (“API”), product stability and shelf life, and the opportunity for both passive and active targeting of cancer tumors.

Manufacturing Process:

Traditional liposome manufacturing processes are often costly and require time consuming preparation steps that yield variable products that often lead to poor encapsulation of active compounds (APIs). Aside from the difficult and cumbersome multi-step manufacturing processes, existing liposomal technology suffers from a lack of utility. To date only water soluble drug compounds have been successfully encapsulated in liposomes and approved as marketed drugs. Furthermore, documented efforts with limited success and very low encapsulation of water insoluble drugs (hydrophobic molecules like the taxane analogs) have been reported. To date, there have been no successful development programs known to have efficiently encapsulated water insoluble drug products.

We believe that the Azaya PSN technology opens the doors for the enhancement of existing marketed drugs, and allows for the delivery of new chemical entities that would otherwise be shelved for solubility reasons.

Traditional Manufacturing Process vs. Azaya’s PSN technology:

A typical manufacturing process of a liposome product requires a cumbersome multi-step process. In one example, the process starts with the pre-formation of empty liposomes; an empty lipid membrane (shell) consisting of phospholipids and cholesterol. These empty liposomes are than loaded with an API into the aqueous core by a gradient or diffusion process utilizing either charge or pH gradient methods. These methods are tedious and require highly controlled conditions to achieve reliable loading of API material. Note: these methods are limited to water soluble drugs and suffer a lack of utility.

After the liposome has been loaded they are then resized using filter excursion methods that are incompatible with lipid loading of hydrophobic APIs. The final material is sterilized via aseptic filtration and dispensed as a solvated product ready for distribution. Depending on the product, the sequences of events can vary depending on the API’s stability. In addition, there are other alternative methods that produce similar liposomal products that encapsulate the active ingredient within the aqueous core.

The demanding manufacturing process to prepare a liposome encapsulated material is expensive. Although materials are readily accessible, the gradient loading of the liposome is work intensive requiring highly qualified scientists, costly analysis and extensive quality testing.

Current liposome preparation utilizes the internal compartment of the liposome to carry the active pharmaceutical ingredient (aqueous core). As a result, water soluble drugs/compounds have been encapsulated, limiting the use of liposomal formulation. Conventional technologies offer have resulted in a few of marketed liposomal drugs; cytarabine (Depocyt), doxorubicin (Myocet and Doxil), and daunorubicin (DaunoXome), Amphotericin B (AmBiosome), and T4N5 (Dimericine).

To date, there has been very little success encapsulating water insoluble drugs (hydrophobic molecules like the taxane analogs). The limited success that has been observed has resulted in variable very low loading concentrations with hydrophobic drugs i.e. taxol and docetaxel using conventional methods. Furthermore, very few reports attempting to encapsulate hydrophobic molecules (taxanes) have been published, reporting limited success with very low concentration of encapsulated drug i.e. mole % of active ingredient vs. lipids.

Azaya Therapeutics Manufacturing Process:

The PSN technology is unique in several ways. First, the process for generating, loading and sizing the liposomal product is a one step process. The natural excipients (phospholipids, cholesterol, protein and active ingredient) are mixed together and processed in a microfluidizer (high pressure homogenizer). The formulation mixture is processed several times until the desired particle size of <100 nm is achieved. Once The processed material is then filtered (aseptic filtration) and lyophilized (concentrated) to afford a dry powder cake for final distribution.

The major advantages of Azaya’s process manufacturing include; abbreviated processing time compared to conventional methods, large scope of utility (offers opportunities to formulate hydrophobic molecules), and extended product shelf life. The processing time is less laborious compared to conventional methods and doesn’t require the extensive quality control that has been necessary for existing processes. There are no labor intensive gradient diffusion steps required to load aqueous soluble APIs. Azaya PSN technology offers the ability to load hydrophobic (water insoluble) ingredients, while generating nanoparticles in one-step process. Unlike the traditional methods, Azaya’s final product is marketed as a dry powder that is reconstituted with easy operating procedures at the physician’s office. In addition, the final product offers an extended the shelf half life 5–10 fold over typical liposomal products as a dried powder. Finally, Azaya’s PSN technology offers a broad application for the formulation of unique drug products.

How does PSN technology differ from conventional liposome formulations?
Liposome delivery of pharmaceutically active drugs has been studied over the past several decades. However, as stated above, there are several issues that have plagued the technology including; loading capacities, retention of drug product, and cost of manufacturing and scope of drug types that can be encapsulated.

Historically, liposome technologies have utilized the internal aqueous compartment of the liposome to carry the active pharmaceutical ingredient (aqueous core; figure 1). To date, several products utilizing liposome technologies that have been successfully marketed include; cytarabine (Depocyt), doxorubicin (Myocet and Doxil), and daunorubicin (DaunoXome), Amphotericin B (AmBiosome), and T4N5 (Dimericine), each of these compounds is water soluble.

Utilizing the same principles found in conventional liposomes, cytotoxic agents encapsulated in a liposome have the ability to target cancerous tumors through a passive targeting mechanism know as the enhance permeation and retention (EPR) effect. Tumor cells allow small particles into the tumor through vasculature leakages while retaining the larger particles i.e. liposome of <200 nm. This allows the cytotoxic agent to be delivered directly to the tumor increasing the local concentration of active compound. This can result in a more efficacious drug.

Unlike conventional technologies, PSN technology offers an active targeting mechanism for cancerous tumors. The PSN technology utilizes an albumin protein to help stabilize the liposomal product. This protein (albumin) has been recently shown to exhibit a high affinity for a protein called secreted protein, acidic and rich in cysteine (SPARC). SPARC is found in much higher concentration in tumor cells and is used to help recruit nutrients to the defunct tumor cells to promote cell growth. Cancer cells require a large amount of nutrients to grown and as a result needs to be feed. As such, albumin has many different functions including the transport of nutrients in the body. In this case, SPARC binds to albumin and transports these nutrients via albumin to the cancer cell. Hence, albumin stabilized liposome is believed to have an affinity for SPARC and is delivered to the cancerous cell, delivering the active ingredient to the site of action. Furthermore, liposomes are made of natural products found naturally in the body that help feed tumors for continual.