Nitroso Impurities in Drug Products: An Overview of Risk Assessment, Regulatory Milieu, and Control Strategy.

Many nitrosamines have been recognized to be carcinogenic for many decades. Despite the fact that several nitrosamine precursors are frequently used in the manufacturing of pharmaceutical products, their potential presence in pharmaceutical products has previously been overlooked due to a lack of understanding on how they form during the manufacturing process. From the risk assessment, it is clear that nitrosamines or their precursors may be present in any component of the finished dosage form. As a risk mitigation strategy, components with a high potential to form nitrosamine should be avoided. In the absence of suitable alternatives, sufficient measures to maintain nitrosamines below acceptable intake levels must be applied. Excipient manufacturing pathways must be extensively studied in order to identify probable excipient components that may contribute to nitrosamine formation. The manufacturers must not solely rely on pharmacopeial specifications for APIs and excipients, rather, they should also develop and implement additional strategies to control nitrosamine impurities. The formulation can be supplemented with nitrosating inhibitors, such as vitamin C, to stop the generation of nitrosamine. The purpose of this review is to identify key risk factors with regard to nitrosamine formation in pharmaceutical dosage forms and provide an effective control strategy to contain them below acceptable daily intake limits.

Data integrity issues in pharmaceutical industry: Common observations, challenges and mitigations strategies.

Data integrity (DI) reaffirms the pharmaceutical industry's commitment to manufacture drugs that are safe, effective and fulfil quality standards. At the same time, DI is a crucial tool for regulatory authorities to use in protecting public health. Recent FDA Form-483 observations and warning letters indicate that DI is the main issue the pharmaceutical industry is currently dealing with. Failure to comply with DI requirements may result in a high number of un-validated results, which may cause post-marketing issues and frequent product recalls. To address the underlying causes of DI problems, a comprehensive approach is necessary. The majority of DI issues are caused by poor quality culture, organizational or individual behaviour, leadership, processes, or technology. DI should be effectively integrated into the quality management system, and it should apply to both paper and electronic records. Employees should be trained on 21 CFR Part 11. Consistent review and audit are required to ensure that procedures are followed and audit trails are generated. Electronic systems, in addition to being an efficient solution (system integration, data verification at both input and output, security), offer advantages over traditional paper-based systems in terms of improved compliance with DI regulatory requirements. For example, many electronic system platforms provide enhanced security features and audit trail capabilities. Finally, management support for data governance is essential for successful implementation of DI. This article reviews commonly observed deviations by FDA pertaining to DI and discusses measures to be undertaken to avoid them.

Biowaiver Monograph for Immediate-Release Solid Oral Dosage Forms: Levocetirizine Dihydrochloride.

Levocetirizine, a histamine H1-receptor antagonist, is prescribed to treat uncomplicated skin rashes associated with chronic idiopathic urticaria as well as the symptoms of both seasonal and continual allergic rhinitis. In this monograph, the practicality of using Biopharmaceutics Classification System (BCS) based methodologies as a substitute for pharmacokinetic studies in human volunteers to appraise the bioequivalence of immediate-release (IR) oral, solid dosage forms containing levocetirizine dihydrochloride was investigated, using data from the literature and in-house testing. Levocetirizine's solubility and permeability properties, as well as its dissolution from commercial products, its therapeutic uses, therapeutic index, pharmacokinetics and pharmacodynamic traits, were reviewed in accordance with the BCS, along with any reports in the literature about failure to meet bioequivalence (BE) requirements, bioavailability issues, drug-excipient interactions as well as other relevant information. The data presented in this monograph unequivocally point to classification of levocetirizine in BCS Class 1. For products that are somewhat supra-equivalent or somewhat sub-equivalent, clinical risks are expected to be insignificant in light of levocetirizine's wide therapeutic index and unlikelihood of severe adverse effects. After careful consideration of all the information available, it was concluded that the BCS-based biowaiver can be implemented for products which contain levocetirizine dihydrochloride, provided (a) the test product comprises excipients that are typically found in IR oral, solid drug products that have been approved by a country belonging to or associated with ICH and are used in quantities that are typical for such products, (b) data supporting the BCS-based biowaiver are gathered using ICH-recommended methods, and (c) all in vitro dissolution requirements specified in the ICH guidance are met by both the test and comparator products (in this case, the comparator is the innovator product).

Biowaiver Monograph for Immediate-Release Solid Oral Dosage Forms: Sitagliptin Phosphate Monohydrate.

Sitagliptin is an antihyperglycemic drug used in adults for the treatment of diabetes Type 2. Literature data and in-house experiments were applied in this monograph to assess whether methods based on the Biopharmaceutics Classification System (BCS) could be used to assess the bioequivalence of solid immediate-release (IR) oral dosage forms containing sitagliptin phosphate monohydrate, as an alternative to a pharmacokinetic study in human volunteers. The solubility and permeability characteristics of sitagliptin were reviewed according to the BCS, along with dissolution, therapeutic index, therapeutic applications, pharmacokinetics, pharmacodynamic characteristics, reports of bioequivalence (BE) / bioavailability problems, data on interactions between the drug and excipients and other data germane to the subject. All data reviewed in this monograph unambiguously support classification of sitagliptin as a BCS Class 1 drug. In light of its broad therapeutic index and lack of severe adverse effects, the clinical risks associated with moderately supraoptimal doses were deemed inconsequential, as were the risks associated with moderately suboptimal doses. Taking all evidence into consideration, it was concluded that the BCS-based biowaiver can be implemented for solid IR oral drug products containing sitagliptin phosphate monohydrate, provided (a) the test product is formulated solely with excipients commonly present in solid IR oral drug products approved in ICH or associated countries and used in amounts commonly applied in this type of product, (b) data in support of the BCS-based biowaiver are obtained using the methods recommended by the WHO, FDA, EMA or ICH and (c) the test product and the comparator product (which is the innovator product in this case) meet all in vitro dissolution specifications provided in the WHO, FDA, EMA or ICH guidance.

Biowaiver Monograph for Immediate-Release Solid Oral Dosage Forms: Moxifloxacin Hydrochloride.

In this monograph, literature data is reviewed to evaluate the feasibility of waiving in vivo bioequivalence testing and instead applying the Biopharmaceutics Classification System (BCS) based methods to the approval of immediate-release solid oral dosage forms containing moxifloxacin hydrochloride as the sole active pharmaceutical ingredient. To facilitate the feasibility decision, solubility and permeability and dissolution characteristics in the context of the BCS, therapeutic index, therapeutic use, pharmacokinetic parameters, bioequivalence/bioavailability issues, drug-excipient interactions and other relevant data were taken into consideration. Moxifloxacin is a BCS class I drug with a wide therapeutic index. Bioequivalence risks arising from the presence of different excipients in the formulation and due to manufacturing variables were deemed to be low. The risks can be further reduced if the choice of excipients is limited to those present in products already approved in International Conference on Harmonisation or associated countries and if the results of in vitro dissolution studies comply with the specifications stipulated in the appropriate biowaiver guidelines. Under these conditions, we conclude that a BCS-based biowaiver can be recommended for moxifloxacin immediate-release solid oral dosage forms.

Selective laser sintering 3D printing - an overview of the technology and pharmaceutical applications.

Food and Drug Administration (FDA) has approved a drug product (Spritam®) and many medical devices manufactured by three-dimensional printing (3DP) processes for human use. There is immense potential to print personalized medicines using 3DP. Many 3DP methods have been reported in the literature for pharmaceutical applications. However, selective laser sintering (SLS) printing has remained least explored for pharmaceutical applications. There are many advantages and challenges in adopting a SLS method for fabrication of personalized medicines. Solvent-free nature, availability of FDA approved thermoplastic polymer/excipients (currently used in hot melt-extrusion process), minimal/no post-processing step, etc. are some of the advantages of the SLS printing process. Major challenges of the technology are requirement of at least one thermoplastic component in the formulation and thermal stability of drug and excipients. This review provides an overview of the SLS printing method, excipient requirements, process monitoring, quality defects, regulatory aspects, and potential pharmaceutical applications.

Integrating QbD Tools for Flexible Scale-Up Batch Size Selection for Solid Dosage Forms.

The pilot scale batch size for solid oral dosage forms is currently defined by major regulatory agencies as one-tenth of the full production, or 100,000 units, whichever is larger. The current criterion is arbitrary and is not based on scientific and risk assessment principles. The approach does not consider geometric, kinematic, and dynamic changes that come into play on scale-up. Even if this criterion is met, impact of scale-up on critical quality attributes cannot be ruled out and also reproducibility cannot be assured simply by restricting the scale-up size. In keeping with the vision for the 21st Century Good Manufacturing Practice initiative to build quality into the product, it is imperative that the selection of scale-up batch size be based on science and risk assessment principles and be part of the product development program. Scale-up should never be seen as an isolated activity. This article will review various tools that can be integrated with quality by design for flexible batch size selection during scale-up.

Additive Manufacturing with 3D Printing: Progress from Bench to Bedside.

Three-dimensional (3D) printing was discovered in the 1980s, and many industries have embraced it, but the pharmaceutical industry is slow or reluctant to adopt it. Spiritam® is the first and only 3D-printed drug product approved by FDA in 2015. Since then, the FDA has not approved any 3D-printed drug product due to technical and regulatory issues. The 3D printing process cannot compete with well-established and understood conventional processes for making solid dosage forms. However, pharmaceutical companies can utilize it where mass production is not required; rather, consistency, precision, and accuracy in quality are paramount. There are many 3D printing technologies available, and not all of them are amenable to pharmaceutical manufacturing. Each 3D technology has certain prerequisites in terms of material that it can handle. Some of the pertinent technical and regulatory issues are as follows: Current Good Manufacturing Practice, in-process tests and process control, and cleaning validation. Other promising area of 3D printing use is printing medications for patients with special needs in a hospital and/or pharmacy setting with minimum regulatory oversight. This technology provides a novel opportunity for in-hospital compounding of necessary medicines to support patient-specific medications. However, aspects of the manufacturing challenges and quality control considerations associated with the varying formulation and processing methods need to be fully understood before 3D printing can emerge as a therapeutic tool. With these points in mind, this review paper focuses on 3D technologies amenable for pharmaceutical manufacturing, excipient requirement, process understanding, and technical and regulatory challenges.

Is the demonstration of bioequivalence for clavulanic acid required in amoxicillin-clavulanic acid orally administered immediate-release products?

OBJECTIVES: Bioequivalence (BE) criteria for amoxicillin-clavulanic acid (Co-amoxiclav) oral formulations are based on 90% confidence interval for both amoxicillin and clavulanic acid. The aim of this work is to explore the relevance of demonstrating BE of clavulanic acid in Co-amoxiclav oral formulations and also to assess the impact on safety and efficacy of product due to bioinequivalent clavulanic acid. METHODS AND KEY FINDINGS: The subtherapeutic levels of clavulanic acid would continue to exert their action against ß-lactamases due to postß-lactamase inhibitor effect. Additionally, only minute quantities are required to inhibit ß-lactamases. Majority of adverse effects associated with Co-amoxiclav are of less serious nature, therefore, risk due to suprabioavailable clavulanic acid was determined to be low. 'Very rapid clavulanic acid release' in in vitro dissolution test would ensure that clinically significant differences between test and reference formulations if any are detected in advance. As an additional risk mitigation strategy, WHO recommends qualitative and quantitative composition similarity between test and reference formulations to ensure excipients do not adversely impact bioavailability. CONCLUSIONS: Co-amoxiclav with non-bioequivalent clavulanic acid, but bioequivalent amoxicillin would still achieve its therapeutic objectives without exposing patients to unwanted adverse effects. Therefore, the current regulatory criterion of demonstrating BE of clavulanic acid appears conservative.

Integrating biopharmaceutics risk assessment and in vivo absorption model in formulation development of BCS class I drug using the QbD approach.

OBJECTIVE: Clinically relevant critical quality attributes (CQA's) were identified for the development of generic drug products containing fluconazole and potential design spaces relevant to the clinical application of the drug candidate was explored. SIGNIFICANCE: A simplified scoring system for the biopharmaceutics risk assessment roadmap (BioRAM) is proposed to guide product development. METHODS: Factorial design of experiments was employed to study the effect of formulation and process variables on CQA's. The in vivo model was developed for predicting the fraction of drug absorbed and to identify the effect of formulation components on drug absorption. RESULTS: BioRAM yielded low scores for fluconazole absorption with respect to severity (risks of sub and supra-bioavailable drug products), probability of incidence of bioinequivalent results and capacity of detection. The results demonstrated that dissolution was highly influenced by the active pharmaceutical ingredient (API) polymorphism and the ratio of diluents. Process variables (mixing time, lubricant concentration, lubrication time and filling speed) did not impact the clinical outcome of the formulation with respect to dissolution and content uniformity. CONCLUSIONS: Understanding the clinical implications of the adopted formulation approach led to the construction of purposeful design space and control strategy.

Pharmaceutical product development: A quality by design approach.

The application of quality by design (QbD) in pharmaceutical product development is now a thrust area for the regulatory authorities and the pharmaceutical industry. International Conference on Harmonization and United States Food and Drug Administration (USFDA) emphasized the principles and applications of QbD in pharmaceutical development in their guidance for the industry. QbD attributes are addressed in question-based review, developed by USFDA for chemistry, manufacturing, and controls section of abbreviated new drug applications. QbD principles, when implemented, lead to a successful product development, subsequent prompt regulatory approval, reduce exhaustive validation burden, and significantly reduce post-approval changes. The key elements of QbD viz., target product quality profile, critical quality attributes, risk assessments, design space, control strategy, product lifecycle management, and continual improvement are discussed to understand the performance of dosage forms within design space. Design of experiments, risk assessment tools, and process analytical technology are also discussed for their role in QbD. This review underlines the importance of QbD in inculcating science-based approach in pharmaceutical product development.

Exploratory Investigation of the Limiting Steps of Oral Absorption of Fluconazole and Ketoconazole in Children Using an In Silico Pediatric Absorption Model.

Due to the higher total clearance of certain drugs in children than in adults, it is recommended that, in such cases, higher relative doses on a milligram/kilogram basis should be administered to children in order to achieve similar systemic exposure to adults. This is the case for fluconazole and ketoconazole. Even though the lower absorptive surface area and smaller volumes of intestinal fluids in children does not affect fluconazole absorption, cumulative fraction absorbed of ketoconazole seems to be dose dependent. A dose of 200 mg of ketoconazole, which belongs to the class 2a of the Developability Classification System (DCS) in adults, seems to be higher than the maximum absorbable dose in children, and ketoconazole absorption is expected to be solubility limited (i.e., DCS class 2b) in this population, indicating a DCS class migration. Therefore, extrapolating DCS and DCS drug classification from adults to pediatric groups does not seem to be straightforward and the development of specific pediatric classification systems should be a high priority.

Risk assessment for extending the Biopharmaceutics Classification System-based biowaiver of immediate release dosage forms of fluconazole in adults to the paediatric population.

OBJECTIVES: The paediatric population undergoes developmental changes in gastric pH, gastric emptying, intestinal transit time, membrane permeability, protein binding, body water, distribution and metabolism. It is widely recognised that changes in these parameters may result in an alteration of the plasma profile and thus in key bioequivalence parameters such as Cmax (maximum plasma concentration of drug) and area under the plasma concentration vs time profile curve. The aim of this work is to assess the risk of extending the biowaiver for immediate release dosage formulations of fluconazole from the adult to the paediatric population. METHODS AND KEY FINDINGS: Fluconazole exhibits good solubility and very rapid dissolution characteristics in various pH media. The absorption of fluconazole in children is known to be complete (over 90%) and not impaired by elevated pH, which is prevalent during the early days of life. Dose numbers calculated using body surface area are less than 1. Therefore, the risk to drug absorption due to differences in gastric pH, gastric emptying, intestinal transit, membrane permeability and metabolising enzymes between adults and children is considered low. CONCLUSIONS: Thus, it can be safely concluded that fluconazole meets highly soluble and highly permeable criteria in the paediatric population and can be allocated to class 1 of the Biopharmaceutics Classification System (BCS) for this population as well as in adults. Additionally, fluconazole has an excellent safety profile in children, similar to that in adults. The BCS-based biowaiver claimed in adults can be safely extended to the paediatric population provided that the requirements in excipient selection and dissolution profile comparison using BCS-based dissolution conditions as stated in the biowaiver monograph for fluconazole immediate release dosage forms in adults are fulfilled.

Biowaiver monograph for immediate-release solid oral dosage forms: bisoprolol fumarate.

Literature data relevant to the decision to allow a waiver of in vivo bioequivalence (BE) testing for the approval of immediate-release (IR) solid oral dosage forms containing bisoprolol as the sole active pharmaceutical ingredient (API) are reviewed. Bisoprolol is classified as a Class I API according to the current Biopharmaceutics Classification System (BCS). In addition to the BCS class, its therapeutic index, pharmacokinetic properties, data related to the possibility of excipient interactions, and reported BE/bioavailability problems are taken into consideration. Qualitative compositions of IR tablet dosage forms of bisoprolol with a marketing authorization (MA) in ICH (International Conference on Harmonisation) countries are tabulated. It was inferred that these tablets had been demonstrated to be bioequivalent to the innovator product. No reports of failure to meet BE standards have been made in the open literature. On the basis of all these pieces of evidence, a biowaiver can currently be recommended for bisoprolol fumarate IR dosage forms if (1) the test product contains only excipients that are well known, and used in normal amounts, for example, those tabulated for products with MA in ICH countries and (2) both the test and comparator dosage form are very rapidly dissolving, or, rapidly dissolving with similarity of the dissolution profiles demonstrated at pH 1.2, 4.5, and 6.8.

Tulsi oil as a potential penetration enhancer for celecoxib transdermal gel formulations.

The focus of the present study was to develop and evaluate the transdermal system of celecoxib. Transdermal gels composed of carbopol 940 in propylene glycol (PG) containing penetration enhancers. The formulations were characterized by permeation, pharmacokinetics, pharmacodynamics and histopathology. Celecoxib permeation across excised rat skins were statistically (p < 0.05) enhanced by tulsi oil compared to turpentine oil containing formulations. In comparison to orally administered formulations, the pharmacokinetic parameters of gel and control formulations were significantly higher (p < 0.05). The maximum plasma concentration (Cmax) obtained with formulations containing 4% turpentine and 6% tulsi oil was, respectively, 1.52 and 2.41 times higher than the formulations without penetration enhancer. Similarly, area under the curve (AUC) of these formulations was 1.70 and 2.40 times higher than the formulations without penetration enhancers. Anti-inflammatory studies demonstrated a statistically significant (p < 0.05) pharmacodynamics profile for the transdermal gel formulations compared to orally administered and control celecoxib formulations. Histopathological studies revealed some disruption in the epidermis without any toxic effect on the dermis layer of skin by penetration enhancers. In summary, the transdermal gel formulations of celecoxib containing penetration enhancers sustained drug level in the blood and will reduce the dose frequency as required with its conventional oral formulation.

Quality by design approach for formulation development: a case study of dispersible tablets.

The focus of the current investigations was to apply quality by design (QbD) approach to the development of dispersible tablets. Critical material and process parameters are linked to the critical quality attributes of the product. Variability is reduced by product and process understanding which translates into quality improvement, risk reduction and productivity enhancement. The risk management approach further leads to better understanding of the risks, ways to mitigate them and control strategy is proposed commensurate with the level of the risk. Design space in combination with pharmaceutical quality management system provide for flexible regulatory approaches with opportunity for continuous improvement that benefit patient and manufacturer alike. The development of dispersible tablet was proposed in the current study through a QbD paradigm for a better patient compliance and product quality. The quality target product profile of a model biopharmaceutical class II drug was identified. Initial risk analysis led to the identification of the critical quality attributes. Physicochemical characterization and compatibility studies of the drug with commonly used excipients were performed. Experiments were designed with focus on critical material and process attributes. Design space was identified and risk factors for all the possible failure modes were below critical levels after the implementation of control strategy. Compliance to the design space provides an opportunity to release batches in a real time. In conclusion, QbD tools together with risk and quality management tools provided an effective and efficient paradigm to build the quality into dispersible tablet.

Electroporation: an avenue for transdermal drug delivery.

The stratum corneum (SC) is a primary rate limiting barrier to permeation of drug molecules through the skin. Small molecular weight lipophilic drugs that are effective at low doses can be effectively delivered by passive transdermal delivery. The SC does not permit passage of polar/hydrophilic and macromolecules. Passive and physical penetration enhancements strategies are used to overcome this barrier property of the SC. Passive penetration enhancement techniques include use of supersaturated solutions and penetration enhancers. In general, the drug delivery potential of chemical modalities is limited. Therefore, physical permeation enhancement techniques gained a lot of focus in the recent past. Physical penetration enhancement techniques include iontophoresis, electroporation and sonophoresis. Electroporation utilizes high voltage pulses that are applied for a very short time to permeabilize the skin to facilitate transport of macromolecules and hydrophilic compounds. Several drugs have been administered via this system successfully. This review presents an overview of in-vitro and in-vivo studies demonstrating therapeutic benefits offered by electroporation assisted permeation. Factors affecting electroporation, synergism between electroporation and other penetration enhancing strategies are also discussed.

In-vivo evaluation in rats of colon-specific microspheres containing 5-fluorouracil.

The aims of this investigation were to determine the distribution in the gastrointestinal (GI) tract of Eudragit S-100 encapsulated colon-specific sodium alginate microspheres containing 5-fluorouracil (5-FU) in rats, and to perform pharmacokinetic and pharmacodynamic studies. Comparisons were with a control immediate-release (IR) formulation of 5-FU. 5-FU was distributed predominantly in the upper GI tract from the IR formulation but was distributed primarily to the lower part of the GI tract from the microsphere formulation. No drug was released in the stomach and intestinal regions from the colon-specific microspheres. Significantly, a high concentration of the active drug was achieved in colonic tissues from the colon-specific microspheres (P < 0.001), which was higher than the IC50 required to halt the growth of and/or kill colon cancer cells. Colon cancer was induced in rats by subcutaneous injection of 1,2-dimethylhydrazine (40 mg kg (-1)) for 10 weeks. The tumours induced were non-invasive adenocarcinomas and were in Duke's stage A. The 5-FU formulations were administered for 4 weeks after tumour induction. Non-significant reductions in tumour volume and multiplicity were observed in animals given the colon-specific microspheres. Enhanced levels of liver enzymes (SGOT, SGPT and alkaline phosphatase) were found in animals given the IR formulation of 5-FU, and values differed significantly (P < 0.001) from those in animals treated with the colon-specific microspheres. Elevated levels of serum albumin and creatinine, and leucocytopenia and thrombocytopenia were observed in the animals given the IR formulation. In summary, Eudragit S-100 coated alginate microspheres delivered 5-FU to colonic tissues, with reduced systemic side-effects. A long-term dosing study is required to ascertain the therapeutic benefits.

Characterization of 5-fluorouracil microspheres for colonic delivery.

The purpose of this investigation was to prepare and evaluate the colon-specific microspheres of 5-fluorouracil for the treatment of colon cancer. Core microspheres of alginate were prepared by the modified emulsification method in liquid paraffin and by cross-linking with calcium chloride. The core microspheres were coated with Eudragit S-100 by the solvent evaporation technique to prevent drug release in the stomach and small intestine. The microspheres were characterized by shape, size, surface morphology, size distribution, incorporation efficiency, and in vitro drug release studies. The outer surfaces of the core and coated microspheres, which were spherical in shape, were rough and smooth, respectively. The size of the core microspheres ranged from 22 to 55 microm, and the size of the coated microspheres ranged from 103 to 185 microm. The core microspheres sustained the drug release for 10 hours. The release studies of coated microspheres were performed in a pH progression medium mimicking the conditions of the gastrointestinal tract. Release was sustained for up to 20 hours in formulations with core microspheres to a Eudragit S-100 coat ratio of 1:7, and there were no changes in the size, shape, drug content, differential scanning calorimetry thermogram, and in vitro drug release after storage at 40 degrees C/75% relative humidity for 6 months.

Ophthalmic delivery of ciprofloxacin hydrochloride from different polymer formulations: in vitro and in vivo studies.

Reservoir-type ocular inserts were fabricated using sodium alginate containing ciprofloxacin hydrochloride as the core (drug reservoir) that was sandwiched between the Eudragit and/or polyvinylacetate films. Ocular inserts were packaged in aluminium foil and sterilized by gamma radiation. These were tested for sterility as per British Pharmacopoeia (BP). Ocular inserts were evaluated for in vitro release rate studies, microbial efficacy, in vivo release studies, efficacy against induced bacterial conjunctivitis in rabbit's eyes, concentration in the aqueous humor, and stability studies as per the International Conference on Harmonization (ICH) guidelines. Ocular inserts passed the test for sterility. They showed zero-order release of the drug in the in vitro and in vivo release studies over a period of 120 hr. The drug was found to be active against selected microorganisms as was proved by microbial efficacy studies. A high correlation coefficient was found between in vitro and in vivo release rate studies. Better improvement was observed in artificially induced bacterial conjunctivitis in rabbit's eyes, compared with marketed eye drops and placebo. Drug concentration in the aqueous humor was found above Minimum Inhibitory Concentration (MIC-90) against selected microorganisms. Shelf-life of the product was found to be more than 2 years.