**5. Conclusion**

The oral route of administration remains formidable in the systemic delivery of therapeutics. It affords patient compliance, ease of administration and flexibility and remains the favourite choice for administration by patients. However, orally administered therapeutics may undergo premature release in the upper GIT which may render them to enzymatic or pH degradation. Therapeutics that are delivered to the absorptive window are susceptible to efflux pump and metabolic enzymes (e.g., cytochrome P450 enzymes) within the GIT epithelia, which is itself a structural barrier. Scientist involved in the design of therapeutics intended for GI delivery must be cognizant of the above constraints and balance these with the physicochemical properties of the therapeutic. Recent evidence attest to the fact that appropriately formulated NP may be fit for this pursuit. In this regard, chitosan NP is the subject of intense interest because it is readily available, biocompatible, biodegradable, mucoadhesive and influences traversing of therapeutics across the GI epithelia. We expect to see more evidence on the application of chitosan in the oral delivery of therapeutics, especially in the form of NP. Further studies on toxicity related issues *in vivo* will assist in discerning any unanticipated effects in humans. These will pave the way for running clinical trials in humans in near future.

**41**

**Author details**

and Nashiru Billa2

\*Address all correspondence to: nbilla@qu.edu.qa

provided the original work is properly cited.

\*

2 College of Pharmacy, QU Health, Qatar University, Doha, Qatar

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

1 The University of Nottingham Malaysia Campus, Malaysia

Rayan Sabra1

*Gastrointestinal Delivery of APIs from Chitosan Nanoparticles*

*DOI: http://dx.doi.org/10.5772/intechopen.95363*

*Gastrointestinal Delivery of APIs from Chitosan Nanoparticles DOI: http://dx.doi.org/10.5772/intechopen.95363*

*Chitin and Chitosan - Physicochemical Properties and Industrial Applications*

available on site for its chemotherapeutic activity against tumour [116].

This was prompted by the mucoadhesive effect imposed by chitosan.

the way for running clinical trials in humans in near future.

The oral route of administration remains formidable in the systemic delivery of therapeutics. It affords patient compliance, ease of administration and flexibility and remains the favourite choice for administration by patients. However, orally administered therapeutics may undergo premature release in the upper GIT which may render them to enzymatic or pH degradation. Therapeutics that are delivered to the absorptive window are susceptible to efflux pump and metabolic enzymes (e.g., cytochrome P450 enzymes) within the GIT epithelia, which is itself a structural barrier. Scientist involved in the design of therapeutics intended for GI delivery must be cognizant of the above constraints and balance these with the physicochemical properties of the therapeutic. Recent evidence attest to the fact that appropriately formulated NP may be fit for this pursuit. In this regard, chitosan NP is the subject of intense interest because it is readily available, biocompatible, biodegradable, mucoadhesive and influences traversing of therapeutics across the GI epithelia. We expect to see more evidence on the application of chitosan in the oral delivery of therapeutics, especially in the form of NP. Further studies on toxicity related issues *in vivo* will assist in discerning any unanticipated effects in humans. These will pave

*4.4.4 Protein drug delivery*

10 mg/ml in rats a 4-fold increase in CUR concentration was detected compared to that of free CUR. Their findings indicated a null release of CUR in the upper GIT and a successful delivery of CUR to the colon with increased bioavailability of delivered CUR with time from CUR-CS-PEC-NPs for 24 h. Hence, rapid degradation metabolism of free CUR was noticed at the same duration. They concluded that this formulation may serve as a suitable delivery system for CUR to the colon in which CUR will be

Proteins are the building blocks of life and required in replicating organisms. Their high molecular weight, chemical and enzymatic susceptibility in the GIT, low diffusion rate through the mucosa barrier and fast systemic clearance, limit their delivery via oral route. As a result, most proteins are administered parenterally. Fortunately, chitosan-based NP are emerging as promising means for the delivery of protein drugs by the oral route through a combination of shielding GI pH, enzymatic degradation and facilitation of epithelial uptake [117]. In a study by He et al., chitosan-STPP insulin NP (CS/STPP/insulin) were orally administered to Type I diabetic rat models in comparison to free insulin solution. Free insulin solution failed to elicit any difference in the blood glucose level, whilst CS/STPP/insulin NP distinctly reduced the blood glucose levels by up to 59% within 8 hours. Crucially, CS/TPP/ insulin NP allowed for a fast recovery of blood sugar level when fasting was halted. Moreover, the CS/TPP/insulin NP exhibited negligible toxicity to liver enzymes, confirming the safety profile of the orally delivered CS/TPP/insulin NP. They concluded that CS/TPP NP are an effective oral delivery vehicle for insulin [118]. In another study, Tan et al. demonstrated better *in vitro* uptake and safety profile from amphotericin B-containing chitosan coated nanostructured lipid carrier (ChiAmpB NLC) than from uncoated NLC [119]. The same authors later demonstrated better *in vivo* uptake from ChiAmpB NLC in rats than from uncoated NCL [120]. They attributed the observed increase in systemic bioavailability to increased mean absorption and mean residence times (MAT and MRT) from ChiAmpB NLC than from naked NLC.

**40**

**5. Conclusion**
