Prescription Screening of Generic Drug

In the consistency evaluation, prescription screening is carried out to determine the key factors affecting the quality of prescriptions. Scientists utilize various experimental designs (such as comparative method, orthogonal design, uniform design, etc.) to screen and determine the type and dosage of key excipients. At Alfa Chemistry, our standard prescription process screening process is:

• Determine the dosage of excipients, and process route/parameters of the prescription
• Screen the prescription with reference to the basic properties of the Reference Listed Drugs (RLDs)'s formulation (compressibility of intermediate granules, fluidity/dissolution rate of tablets, hardness/friability of tablets/injections/capsules-tablets, etc.)
• Adjust the amount of excipients or select new alternative excipients to achieve the same clinical efficacy as the RLD

Evaluation Index

• Appearance
• Color
• Hygroscopicity
• Fluidity
• Solubility
• pH
• Content
• Related substance
• Bacterial endotoxin or pyrogen
• Insoluble particles
• Stability

Figure 1. Simplified outline of the generic drug product-development cycle. (Wang, Y. 1999)

Our Services

Alfa Chemistry provides different prescription screening solutions according to different dosage forms (solid oral dosage forms, liquid formulations, injections) with the application of the single-factor test and orthogonal test.

Solid Oral Dosage Forms

① According to the common dosage and process of excipients, basic properties of the prescription (such as the compressibility and fluidity of the granules and the hardness, friability and moisture of the tablets) are used as indicators for preliminary screening

② Two to three prescription samples with qualified characteristics are selected to conduct dissolution curve testing

③ Adjust the amount of excipients by comparing dissolution curve with the RLD's

④ Select two or three optimal prescription processes to conduct research on the influencing factors, and determine the optimal prescription process based on the results of the compatibility test of excipients

Liquid formulations

① Determine the amount of excipients according to the basic properties of the reference preparation, such as viscosity, taste, osmotic pressure, and pH value

② Determine the amount of the preservatives: If the dosage can be found in the instructions or quality standards of the RLD, we directly refer to the dosage of the RLD. If there is no available information, the lowest effective dose is determined by performing the antibacterial testing

③ Select one or two prescription samples with qualified characteristics to conduct research on the influencing factors, to test the stability and determine the prescription process

Injection

The types and dosages of excipients in generic injections should generally be the same as those in the reference preparation, with an acceptable range of 95% to 105%. The information of type and dosage of injection excipients can be obtained directly from the drug insert sheet and label. We refer to the FDA guidelines "ANDA Submissions-Refuse-to-Receive Standards" to establish appropriate evaluation indicators, and analyze the RLD prescription of injections in combination with performing some experiments.