Photostability Issues in Pharmaceutical Dosage Forms and Photostabilization

Abstract

Photodegradation is one of the major pathways of the degradation of drugs. Some therapeutic agents and excipients are highly sensitive to light and undergo significant degradation, challenging the quality and the stability of the final product. The adequate knowledge of photodegradation mechanisms and kinetics of photosensitive therapeutic entities or excipients is a pivotal aspect in the product development phase. Hence, various pharmaceutical regulatory agencies, across the world, mandated the industries to assess the photodegradation of pharmaceutical products from manufacturing stage till storage, as per the guidelines given in the International Conference on Harmonization (ICH). Recently, numerous formulation and/or manufacturing strategies has been investigated for preventing the photodegradation and enhancing the photostability of photolabile components in the pharmaceutical dosage forms. The primary focus of this review is to discuss various photodegradation mechanisms, rate kinetics, and the factors that influence the rate of photodegradation. We also discuss light-induced degradation of photosensitive lipids and polymers. We conclude with a brief note on different approaches to improve the photostability of photosensitive products.

Photostability of Topical Agents Applied to the Skin: A Review

“…In this context, research dealing with the photodegradation of dermatological drugs as well as photostabilization strategies is summarized in Table 3. The main factors playing an important role in overcoming photoinstability are: formulation factors, UV-absorbers and pigments, antioxidants, cyclodextrins inclusion, vesicular systems, and combination of different techniques [20,21,38,84].…”

“…On the other hand, it should be stressed that following topical administration several papers discussed the lack of photostability testing of pharmaceutical drug substances during or after administration. It is therefore necessary to examine how the existing instruments and existing guidelines aid the understanding of the photostability of topical drugs, which could be exposed to a significant amount of light after application to the skin [10,[17][18][19][20][21].…”

“…On the other hand, several papers discussed the lack of photostability testing of pharmaceutical drug substances during or after administration. It is therefore necessary to examine how the existing instruments and existing guidelines aid the understanding of the photostability of topical drugs, which could be exposed to a significant amount of light after application to the skin [10,[17][18][19][20][21].Two main categories of drug products applied topically to the skin are identified: products applied for local action (creams, gels, sprays, solutions) and products applied for systemic effects-transdermal drug delivery systems. The aim of this study was to conduct a systematic review of the photostability of dermatological drugs applied topically to the skin for local effect.…”

Comparative Evaluation of the Photostability of Carbamazepine Polymorphs and Cocrystals

“…The efficacy, safety, and quality of pharmaceuticals are adversely affected by light exposure. Most drugs are exposed to light during production, storage, distribution, handling, and use [1,2]. Light potentially alters physicochemical properties of the active pharmaceutical ingredients (APIs) and affects the stability of the final products [1][2][3].…”

“…Most drugs are exposed to light during production, storage, distribution, handling, and use [1,2]. Light potentially alters physicochemical properties of the active pharmaceutical ingredients (APIs) and affects the stability of the final products [1][2][3]. Light can provoke the photodecomposition of a drug, which may cause not only a loss of potency of the drug but also the production of a highly toxic compound.…”