Solid lipids nanoparticles (SLNs) are an alternative carrier system to polymeric nanoparticles or liposomes. They consist of physiological and biocompatible lipids. It has been claimed that SLNs offer the combined advantages and avoid the disadvantages of other colloidal carrier systems. The aim of this research work is to fabricate and evaluate the carbocisteine-loaded solid lipid nanoparticles. SLNs were prepared by using glycerol monostearate by a high-pressure homogenization method, using poloxamer 188 as stabilizer to improve drug bioavailability and to reduce particle size. A drug and excipient compatibility study was checked by using FTIR, and it was found that there was no interaction between the drug and excipients. Optimized carbocisteine SLNs were evaluated for zeta potential, particle size, and % drug release, revealing results of -19 mv, 50 to 200 nm, and up to 70.84%, respectively. To check the stability of the formulation, an accelerated stability study was performed and the results show that the formulation was stable. To evaluate SLNs prepared by the HPH method, all the batches were evaluated for various parameters and we found good results. The F6 batch was found to be best among all prepared batches, and the same batch was optimized on the basis of particle size, stability, Zeta potential, and release pattern. SLNs could provide improved advantages of good penetration and targeting to treat pulmonary disease.