How to develop Generic medicine?

A generic drug is identical, or bioequivalent to a brand name drug in dosage form, safety, strength, route of administration, quality, performance characteristics, and intended use.

Generic medicine should be pharmaceutically equivalent to the Reference listed drug which is simply called as RLD. It  the prime responsibility of the Formulation scientist to produce the desired dosage form. Formulation and development is not a single step process it takes lots of efforts. Each company only after market analysis ask the F and D department to proceed for Formulation and development.
Requirement of Generic medicine
  • Contain the same API as the innovator drug (inactive ingredient may vary) 
  • Be identical in strength, dosage form, and route of administration to RLD
  •  Have the same use indications as RLD  
  • be bioequivalent to RLD 
  • meet the same batch requirements for identity, strength, purity and quality 
  • be manufactured under the same strict standards of  GMP regulations required for innovator products
 As a formulation scientist I have summarized some of the steps which will be helpful to the generic player to develop a new product.
Literature study
I have listed some of the points which have to be taken care of during formulation development. The details of the medicine can be accessed form websites. I recommend you to follow always standard and genuine websites. I have listed some of the websites with links. 
1. eMC(electronic medicines compendium )-  emc
2. DailyMed - DailyMed
3. Medscape- Medscape
4.USFDA- USFDA
Above links provide sufficient information well as guideline. The detail literature can give following details 
·         1. Name of the medicinal product
·         2. Qualitative and quantitative composition
·         3. Pharmaceutical form
·         4. Clinical particulars
·         4.1 Therapeutic indications
·         4.2 Posology and method of administration
·         4.3 Contraindications
·         4.4 Special warnings and precautions for use
·         4.5 Interaction with other medicinal products and other forms of interaction
·         4.6 Fertility, pregnancy and lactation
·         4.7 Effects on ability to drive and use machines
·         4.8 Undesirable effects
·         4.9 Overdose
·         5. Pharmacological properties
·         5.1 Pharmacodynamic properties
·         5.2 Pharmacokinetic properties
·         5.3 Preclinical safety data
·         6. Pharmaceutical particulars
·         6.1 List of excipients
·         6.2 Incompatibilities
·         6.3 Shelf life
·         6.4 Special precautions for storage
·         6.5 Nature and contents of container
·         6.6 Special precautions for disposal and other handling
·         The literature study also includes the detailed physiochemical property of the API. This can be obtained from the supplier. One need to consider all the formulation variables, either process variables or the component variables. Following image shows the clear idea about the drug product.
·          Nowadays , Design of experiment is used but in context of Nepal, a simple hit and trial method is used. Before design of experiment on has to establish Quality target Product Profile.
·         Quality Target Product Profile for the ANDA Product
The quality target product profile forms the basis of design for the development of the product. Considerations for the quality target product profile could include:
•  Intended use in clinical setting, route of administration, dosage form, delivery systems
•  Dosage strength(s)
•  Container closure system
• Therapeutic moiety release or delivery and attributes affecting pharmacokinetic characteristics (e.g., dissolution, aerodynamic performance) appropriate to the drug product dosage form being developed
Drug product quality criteria (e.g., sterility, purity, stability, and drug release) appropriate for the intended marketed product
·          But lattice design can be the easiest way for the various trails planning. The each critical parameters has to considered. The literature study gives the excipients but not the grades so as per the target product profile and the process selected the excipients grade selection is equally important. 

      
The excipient grade and the amount of excipient is important to control the quality of the dosage form. A formulation scientist should be well aware about the excipient grades and its rationale use. An excipients should able to impose its property over all the drawbacks of physical property of the API. A good excipients :
a. Controls the process variables
b. Enhance stability
c. Improves Drug release parameters
d. Control Drug release
e. Mask the taste and enhance the palatability.
f. Improve bioavaliablity
g. Reduce the processing cost and improve the product quality.









 Excipients Selection
The excipients chosen, their concentration, and the characteristics that can influence the drug product performance (e.g., stability, bioavailability) or manufacturability should be discussed relative to the respective function of each excipient. This should include all substances used in the manufacture of the drug product, whether they appear in the finished product or not (e.g., processing aids). Compatibility of excipients with other excipients, where relevant (for example, combination of preservatives in a dual preservative system), should be established. The ability of excipients (e.g., antioxidants, penetration enhancers, disintegrants, release controlling agents) to provide their intended functionality, and to perform throughout the intended drug product shelf life, should also be demonstrated. The information on excipient performance can be used, as appropriate, to justify the choice and quality attributes of the excipient, and to support the justification of the drug product specification.

As the API is always fix in the dosage form so a formulation scientist is able to play with the excipients and the process.
Logical selection of the excipients is always superior in terms of Quality. A well characterised excipients always give predictable and reproducible results. 
Compactibility 
Compactibility  study is necessary. So API compatibility study is done at various proportion and it is checked at various condition.
Formulation
During formulation and process development, the formulation scientist should follow those steps which can be reproducible. Precaution should be taken in those steps which may create problem in scale-up. Each step should be note down clearly. Before planing each batch all the process variable which has impact on the characteristic of the dosage form, has to be considered so that it will help during optimization of the batch. During the process each inprocess Quality control test need to be controlled. Care has to be given for Relative Humidity if the API is moisture sensitive.
Books for the formulation of each dosage for will be provided in request.
Invitro evaluation
In vitro evaluation is done as per the pharmacopoeial requirement. The RLD in most of the cases disclose the analytical process.  A narrow range is established by the scientist himself so that during scale up the product won't deviate away from the limit. 
Stability
Stability studies are an essential component of pharmaceutical development, allowing evaluation of active pharmaceutical ingredient (API) stability or drug product stability under the influence of a variety of environmental factors such as temperature, humidity and light. It will be written more in detail in upcoming post.

-Kabin Maleku
Researcher

Micro Labs Advanced Research Centre










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