The development of generic ophthalmic drug products with complex formulations is challenging due to the complexity of the ocular system and a lack of sensitive testing to evaluate the interplay of its physiology with ophthalmic drugs. New methods are needed to facilitate the development of ophthalmic generic drug products. Ocular physiologically based pharmacokinetic (O-PBPK) models can provide insight into drug partitioning in eye tissues that are usually not accessible and/or are challenging to sample in humans. This study aims to demonstrate the utility of an ocular PBPK model to predict human exposure following the administration of ophthalmic suspension. Besifloxacin (Bes) suspension is presented as a case study. The O-PBPK model for Bes ophthalmic suspension (Besivance® 0.6%) accounts for nasolacrimal drainage, suspended particle dissolution in the tears, ocular absorption, and distribution in the rabbit eye. A topical controlled release formulation was used to integrate the effect of Durasite® on Bes ocular retention. The model was subsequently used to predict Bes exposure after its topical administration in humans. Drug-specific parameters were used as validated for rabbits. The physiological parameters were adjusted to match human ocular physiology. Simulated human ocular pharmacokinetic profiles were compared with the observed ocular tissue concentration data to assess the OCAT models\' ability to predict human ocular exposure. The O-PBPK model simulations adequately described the observed concentrations in the eye tissues following the topical administration of Bes suspension in rabbits. After adjustment of physiological parameters to represent the human eye, the extrapolation of clinical ocular exposure following a single ocular administration of Bes suspension was successful.

During the COVID-19 pandemic, intellectual property licensing through bilateral agreements and the Medicines Patent Pool were used to facilitate access to new COVID-19 therapeutics in low- and middle-income countries (LMICs). The lessons learnt from the application of the model to COVID-19 could be relevant for preparedness and response to future pandemics and other health emergencies.The speed at which affordable versions of a new product are available in LMICs is key to the realization of the potential global impact of the product. When initiated early in the research and development life cycle, licensing could facilitate rapid development of generic versions of innovative products in LMICs during a pandemic. The pre-selection of qualified manufacturers, for instance building on the existing network of generic manufacturers engaged during the COVID-19 pandemic, the sharing of know-how and the quick provision of critical inputs such as reference listed drugs (RLDs) could also result in significant time saved. It is important to find a good balance between speed and quality. Necessary quality assurance terms need to be included in licensing agreements, and the potentials of the new World Health Organization Listed Authority mechanism could be explored to promote expedited regulatory reviews and timely access to safe and quality-assured products.The number, capacity, and geographical distribution of licensed companies and the transparency of licensing agreements have implications for the sufficiency of supply, affordability, and supply security. To foster competition and support supply security, licenses should be non-exclusive. There is also a need to put modalities in place to de-risk the development of critical pandemic therapeutics, particularly where generic product development is initiated before the innovator product is proven to be effective and approved. IP licensing and technology transfer can be effective tools to improve the diversification of manufacturing and need to be explored for regional manufacturing for accelerated access at scale in in LMICs and supply security in future pandemics.

UNASSIGNED: This study aims to determine whether the live birth rates were similar between GnRH antagonist original reference product Cetrotide® and generic Ferpront®, in gonadotropin-releasing hormone (GnRH) antagonist protocol for controlled ovarian stimulation (COS).
UNASSIGNED: This retrospective cohort study investigates COS cycles utilizing GnRH antagonist protocols. The research was conducted at a specialized reproductive medicine center within a tertiary care hospital, spanning the period from October 2019 to October 2021. Within this timeframe, a total of 924 cycles were administered utilizing the GnRH antagonist originator, Cetrotide® (Group A), whereas 1984 cycles were undertaken using the generic, Ferpront® (Group B).
UNASSIGNED: Ovarian reserve markers, including anti-Mullerian hormone, antral follicle number, and basal follicular stimulating hormone, were lower in Group A compared to Group B. Propensity score matching (PSM) was performed to balance these markers between the groups. After PSM, baseline clinical features were similar, except for a slightly longer infertile duration in Group A versus Group B (4.43 ± 2.92 years vs. 4.14 ± 2.84 years, P = 0.029). The duration of GnRH antagonist usage was slightly longer in Group B than in Group A (6.02 ± 1.41 vs. 5.71 ± 1.48 days, P < 0.001). Group B had a slightly lower number of retrieved oocytes compared to Group A (14.17 ± 7.30 vs. 14.96 ± 7.75, P = 0.024). However, comparable numbers of usable embryos on day 3 and good-quality embryos were found between the groups. Reproductive outcomes, including biochemical pregnancy loss, clinical pregnancy, miscarriage, and live birth rate, did not differ significantly between the groups. Multivariate logistic regression analyses suggested that the type of GnRH antagonist did not independently impact the number of oocytes retrieved, usable embryos, good-quality embryos, moderate to severe OHSS rate, clinical pregnancy, miscarriage, or live birth rate.
UNASSIGNED: The retrospective analysis revealed no clinically significant differences in reproductive outcomes between Cetrotide® and Ferpront® when used in women undergoing their first and second COS cycles utilizing the GnRH antagonist protocol.

UNASSIGNED: Atrial fibrillation (AF) is the most common abnormal heart rhythm in elderly patients. Rivaroxaban has been widely used for stroke prevention. The anticoagulant response to rivaroxaban increases with age, which may make elderly patients susceptible to adverse outcomes resulting from small differences in bioavailability between generic and brand products.
UNASSIGNED: We designed a cohort study of ≥65-year-old inpatients with AF. Sociodemographic and laboratory measures of qualified patients who received brand or generic rivaroxaban for at least 72 hours at the study hospital from January 2021 to June 2023 were collected retrospectively. The primary outcome was the incidence of bleeding.
UNASSIGNED: A total of 1008 qualifying patients were included for analysis, with 626 (62.1%) receiving brand rivaroxaban and 382 (37.9%) receiving generic rivaroxaban. After propensity score matching and weighting to account for confounders, the odds ratios comparing brand vs generic rivaroxaban (95% confidence intervals) for the bleeding was 1.15 (0.72-1.82). Results from subgroup analyses of patients with age ≥85, HAS-BLED score ≥ 3, containment of antiplatelet drugs, and female patients were consistent with the primary analysis.
UNASSIGNED: It provides evidence regarding the clinical safety outcome of generic rivaroxaban in the elderly AF population that may be particularly susceptible to adverse outcomes resulting from small allowable differences in pharmacokinetics.

In an era of cost pressure, substituting generic drugs represents one of the main cost-containment strategies of healthcare systems. Despite the obvious financial benefits, in a minority of cases, substitution may require caution or even be contraindicated. In most jurisdictions, to obtain approval, the bioequivalence of generic products with the brand-name equivalent needs to be shown via bioavailability studies in healthy subjects. Rare diseases, defined as medical conditions with a low prevalence, are a group of heterogenous diseases that are typically severe, disabling, progressive, degenerative, and life-threatening or chronically debilitating, and disproportionally affect the very young and elderly. Despite these unique features of rare diseases, generic bioequivalence studies are typically carried out with single doses and exclude children or the elderly. Furthermore, the excipients and manufacturing processes for generic/biosimilar products can differ from the brand products which may affect the shelf-life of the product, its appearance, smell, taste, bioavailability, safety and potency. This may result in approval of generics/biosimilars which are not bioequivalent/comparable in their target population or that meet bioequivalence but not therapeutic equivalence criteria. Another concern relates to the interchangeability of generics and biosimilars which cannot be guaranteed due to the phenomenon of biocreep. This review summarizes potential concerns with generic substitution of orphan drugs and discusses potentially problematic cases including narrow therapeutic index drugs or critical conditions where therapeutic failure could lead to serious complications or even death. Finally, we put forward the need for refining regulatory frameworks, with emphasis on Saudi Arabia, for generic substitution and recent efforts toward this direction.

Apixaban is a direct oral Xa inhibitor and is indicated for the treatment of venous thrombo-embolism (VTE) and prevention of stroke in atrial fibrillation (AF). Recently, a generic (ZyQuis, Zydus Lifesciences Limited, India) has received Food and Drug Administration approval. While bioequivalence has been demonstrated with Eliquis (Bristol-Myers Squibb/Pfizer, UK), it is necessary to monitor its effectiveness prior to acceptance in medical practice. This prospective study independently evaluated Apixaban (ZyQuis) at two accredited laboratories. Participants were converted from Warfarin or Rivaroxaban to Apixaban 5 mg bd for a duration of one month. Peak anti-Xa levels were measured 3-4 h post the morning dose. The samples were processed on the Atellica COAG 360 (Siemens Healthineers, Marburg, Germany) analyzers with a chromogenic anti-Xa assay (Innovance, reference interval 69-321 ng/mL). There were 26 participants; 5 men, 21 women; mean ± standard deviation age of 46 ± 12 years. Indications for anticoagulation included: VTE (88.5%) and AF (11.5%). 69.2% of the participants had at least one comorbidity. 96.2% of the anti-Xa levels were within the laboratory\'s 95% reference interval. Mean anti-Xa activity was 191 ± 69 ng/mL and 186 ± 68 ng/mL measured at respective laboratories. Mean differences in anti-Xa measurements represented by Bland-Altman statistics were small (bias of -2.6%, 95% confidence interval -1.11 to -4.09) and a strong correlation was observed on Deming regression analysis (0.995). Apixaban (ZyQuis) was effective for the management of VTE and AF as evidenced by anti-Xa activity.

OBJECTIVE: Clozapine is considered the most reliable drug for treatment-resistant schizophrenia. In 2014, a generic formulation of clozapine (Clzapine) was introduced in Korea. This study was performed to provide clinical information regarding the use of clozapine and to compare efficacy and tolerability when converting from the brand-name formulation (Clozaril) to the generic formulation during longterm maintenance treatment among Korean patients with schizophrenia.
METHODS: This mirror-image study retrospectively investigated the electronic medical records of patients who had switched from Clozaril to Clzapine with a ≥1-year duration for each formulation. Clinical data were collected, including information regarding clozapine use, psychiatric hospitalization, co-medications, and blood test findings. Data before and after the switch were compared using paired t-tests.
RESULTS: Among 332 patients, the mean 1-year dosages were 233.32±149.35 mg/day for Clozaril and 217.36±136.66 mg/day for Clzapine. The mean clozapine concentration-to-dose ratios were similar before and after the switch (Clozaril, 1.33±0.68; Clzapine, 1.26±0.80). Switching from Clozaril to Clzapine resulted in no significant differences in the hospitalization rate, hospitalization duration, or laboratory findings (liver function parameters, serum cholesterol level, and serum glucose level). Equivalent doses of co-prescribed antidepressants were decreased, but concomitant medications otherwise showed no significant differences.
CONCLUSIONS: Clinical efficacy and tolerability appear comparable when switching to Clzapine during clozapine maintenance treatment. This study offers descriptive real-world clinical insights into clozapine maintenance treatment in Korea, thereby providing patients with more treatment options and contributing to the development of maintenance guidelines tailored to the Korean population.

Cambodia has experienced exponential economic growth in recent years and is expected to graduate from least developed country (LDC) status within the next decade. Membership of the World Trade Organization (WTO) will require Cambodia to grant product and process patents for pharmaceuticals upon LDC graduation. This study aims to measure the impact of the WTO Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) on the price of HIV and hepatitis C medicine in Cambodia once it graduates from LDC status and is obliged to make patents available for pharmaceutical products and processes. Using scenarios based on likely outcomes of accession to the TRIPS Agreement, it measures the impact on the price of the HIV treatment program and compares that impact with the hepatitis C treatment program. Graduation from LDC status would be expected to result in a modest increase in the cost of the antiretroviral (ARV) treatment program and very large increases in the cost of the direct acting antivirals (DAA) treatment program. If annual treatment budgets remain constant, patent protection could see 1,515 fewer people living with HIV able to access ARV treatment and 2,577 fewer people able to access DAA treatment (a drop in treatment coverage of 93%).

Most of the government regulatory agencies, including the United States Food and Drug Administration and the European Medicine Agency, demand that the generic complex topical products prove pharmaceutical and bioequivalence. The evaluation of bioequivalence for complex topical dermatological formulations is a challenging task that requires careful consideration of several factors. Although comparative clinical studies are still considered the gold standard approach for establishing bioequivalence in most formulations, these studies can be costly and insensitive to detect formulation differences. Therefore, significant efforts have been made to develop and validate alternative approaches that demonstrate bioequivalence and expedite the availability of high-quality generic topical dermatological products. This article reviews the current methods for determining the bioequivalence of topical formulations in humans, with particular emphasis on recent advances in these methodologies. Most of the alternative methods are sensitive and reproducible, with the capability to ease the financial burden of comparative clinical studies within a short delivery time. The limitations associated with each technique are reviewed in detail.

OBJECTIVE: To assess the effectiveness of generic sofosbuvir (SOF) and branded daclatasvir (DCV) for the treatment of chronic hepatitis C virus (HCV)infected patients.
METHODS: This retrospective study, performed in a single center in Saudi Arabia between August 2017 and July 2022, we enrolled 140 consecutive patients with HCV who received generic SOF and branded DCV. The primary outcome was sustained virologic response at week 12 (SVR12).
RESULTS: The majority of the patients were female (62.1%), infected with genotype 4 (57.9%), and treatment-naïve in 120 (85.7%) patients with baseline cirrhosis in 55 (39.3%). The mean patient age was 61±13.6 years. In the intention-to-treat analysis, 131 (93.6%) patients achieved SVR12. Moreover, 85.7%, 100%, 100%, 88.9%, and 96.3% of genotypes 1a, 1b, 2, 3, and 4, respectively, achieved SVR12. In the per-protocol analysis, 131 (96.3%) patients achieved an SVR of 12. Additionally, 92.3%, 100%, 100%, 88.9%, and 98.7% of the patients with genotypes 1a, 1b, 2, 3, and 4, respectively, achieved SVR12. No HCV virologic breakthroughs occurred. In the subgroup analysis, SVR12 rates were comparable regardless of baseline characteristics, such as treatment history, cirrhosis, and hepatocellular carcinoma. Patients achieving SVR12 showed a significant improvement in post-treatment serum liver enzyme and total bilirubin levels.
CONCLUSIONS: The findings of our study confirm the effectiveness of generic sofosbuvir as a treatment option for HCV infection.