Effect of Counterion on the Solid State Photodegradation Behavior of Prazosin Salts

Abstract

Abstract. The effect of counterion was evaluated on the photodegradation behavior of six prazosin salts, viz., prazosin hydrochloride anhydrous, prazosin hydrochloride polyhydrate, prazosin tosylate anhydrous, prazosin tosylate monohydrate, prazosin oxalate dihydrate, and prazosin camsylate anhydrous. The salts were subjected to UV-Visible irradiation in a photostability test chamber for 10 days. The samples were analyzed for chemical changes by a specific stability-indicating high-performance liquid chromatography method. pH of the microenvironment was determined in 10%w/v aqueous slurry of the salts. The observed order of photostability was: prazosin hydrochloride anhydrous>prazosin camsylate anhydrous∼prazosin-free base>prazosin hydrochloride polyhydrate>prazosin tosylate anhydrous>prazosin oxalate dihydrate∼prazosin tosylate monohydrate. Multivariate analysis of the photodegradation behavior suggested predominant contribution of the state of hydration and also intrinsic photosensitivity of the counterion. Overall, hydrated salts showed higher photodegradation compared to their anhydrous counterparts. Within the anhydrous salts, aromatic and carbonyl counterion-containing salts showed higher susceptibility to light. The pH of microenvironment furthermore contributed to photodegradation of prazosin salts, especially for drug counterions with inherent higher pH. The study reveals importance of selection of a suitable drug salt form for photosensitive drugs during preformulation stage of drug development.

Evolution of Choice of Solubility and Dissolution Media After Two Decades of Biopharmaceutical Classification System

“…The type of water was not specified in 19 of 51 studies (37%) (38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56).…”

“…In the last decade, biorelevant media have been extensively used to determine drug solubility and as dissolution media, especially for BCS class II compounds (14 studies or 25.0%) (8,9,13,22,27,33,35,42,44,45,47,51,54,55) as well as for BCS class I (4 studies or 7.1%) (33,34,49,51), class III (2 or 3.6%) (33,51), and class IV (2 or 3.6%) (33,51). As mentioned, biorelevant media contain generally components which are likely present in the human GI tract such as bile salts and lecithin aiming to mimic the physiological conditions in specific segments of the GI tract; thus, in these media, pH, osmolality, and surface tension are adapted to physiological values (75).…”

Influence of Oil Sands Composition on Bitumen Quality During Non‐Aqueous Bitumen Extraction from the Athabasca Deposit

“…The cumulated percent of CL size that accounts for 50 % or less of the CL (which is the 50th percentile) is called D50. [20] The same procedure was used to determine D10 and D90. Figure 1.…”