This collaborative study was conducted to determine the total monomeric anthocyanin concentration by the pH differential method, which is a rapid and simple spectrophotometric method based on the anthocyanin structural transformation that occurs with a change in pH (colored at pH 1.0 and colorless at pH 4.5). Eleven collaborators representing commercial laboratories, academic institutions, and government laboratories participated. Seven Youden pair materials representing fruit juices, beverages, natural colorants, and wines were tested. The repeatability relative standard deviation (RSDr) varied from 1.06 to 4.16%. The reproducibility relative standard deviation (RSDR) ranged from 2.69 to 10.12%. The HorRat values were < or = 1.33 for all materials. The Study Director recommends that the method be adopted Official First Action.

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Determination of total monomeric anthocyanin pigment content of fruit juices, beverages, natural colorants, and wines by the pH differential method: collaborative study.

https://onlinelibrary.wiley.com/doi/pdf/10.1021/js9601896

Characteristics and Significance of the Amorphous State in Pharmaceutical Systems

Salt Selection and Optimisation Procedures for Pharmaceutical New Chemical Entities

Studies of active drug/excipient compatibility represent an important phase in the preformulation stage of the development of all dosage forms. The potential physical and chemical interactions between drugs and excipients can affect the chemical nature, the stability and bioavailability of drugs and, consequently, their therapeutic efficacy and safety. The present review covers the literature reports of interaction and incompatibilities of commonly used pharmaceutical excipients with different active pharmaceutical ingredients in solid dosage forms. Examples of active drug/excipient interactions, such as transacylation, the Maillard browning reaction, acid base reactions and physical changes are discussed for different active pharmaceutical ingredients belonging to different therapeutic categories viz antiviral, anti-inflammatory, antidiabetic, antihypertensive, anti-convulsant, antibiotic, bronchodialator, antimalarial, antiemetic, antiamoebic, antipsychotic, antidepressant, anticancer, anticoagulant and sedative/hypnotic drugs and vitamins. Once the solid-state reactions of a pharmaceutical system are understood, the necessary steps can be taken to avoid reactivity and improve the stability of drug substances and products.

https://jefc.scholasticahq.com/article/1131.pdf

Interactions and incompatibilities of pharmaceutical excipients with active pharmaceutical ingredients: a comprehensive review

Pharmaceutical evaluation of early development candidates “the 100 mg-approach”

The equilibrium moisture content (EMC) was determined for thirty pharmaceutical excipients. These data are to be included in the forth-coming publication of the Handbook of Pharmaceutical Excipients. This work was undertaken as a collaborative effort under the sponsorship of the Academy of Pharmaceutical Sciences. The results of this study are being reported herein prior to publication of the Handbook.The experimental procedure for determining equilibrium moisture content is included along with a method for classifying the hygroscopic property of solids.

G. Kaplan

Papers

Equilibrium Moisture Content of Pharmaceutical Excipients